This is a working overview of cake, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-15 and is reviewed periodically as new material appears.
Lyophilization is a dehydration process that removes water from a frozen material by sublimation under low pressure. The material is first frozen to convert liquid water into ice. Next, the pressure is reduced below the triple point of water so that ice changes directly into vapor without passing through a liquid phase. This step is called primary drying. The result is a porous solid or cake that retains the original shape of the frozen solution.
After primary drying, secondary drying removes water that remains bound to the material. This stage raises the shelf temperature while maintaining low pressure, which encourages desorption of unfrozen water. Residual moisture can be reduced to a low percentage, improving stability for many products. The process parameters, including freezing rate, shelf temperature, and chamber pressure, influence the final pore structure and reconstitution behavior. Control of these variables helps prevent collapse or meltback during drying.
Stability of a lyophilized product depends on its glass transition temperature, the temperature at which the amorphous cake transitions from a glassy to a rubbery state. Storage below this temperature minimizes molecular mobility and slows chemical degradation. If the storage temperature exceeds the glass transition temperature, the cake may collapse, shrink, or become sticky. Accelerated stability studies at elevated temperatures and humidity help predict shelf life, but they do not always reflect real-time behavior. Residual moisture content also plays a critical role in long-term stability.
Reconstitution involves adding a suitable diluent, often sterile water or a buffer, to the dried cake. Gentle swirling or inversion helps dissolve the material without creating excessive foam. The time required for complete dissolution can range from seconds to several minutes and depends on the cake structure and the diluent. Improper reconstitution, such as vigorous shaking or using the wrong diluent, can cause protein aggregation or loss of activity. After reconstitution, the product may have a limited shelf life and should be used according to its labeling.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | Freeze-drying, lyophilisation | Lyophilization is the American spelling; lyophilisation is British |
| Primary drying mechanism | Sublimation of ice | Occurs under vacuum below the triple point |
| Typical chamber pressure | 0.05-0.5 mbar | Range depends on product and equipment |
| Typical shelf temperature during freezing | -40 to -20 °C | Lower temperatures may be used for labile products |
| Resulting product form | Porous cake or powder | Appearance depends on 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.
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.
Handling and storage practices aim to keep the cake intact and dry. Vials are typically stored upright at controlled temperatures, often between 2 °C and 8 °C or at -20 °C for longer-term use. Reconstitution involves adding a suitable diluent and gently mixing until the solid dissolves. Shaking or rapid injection of diluent can create foam or damage sensitive molecules. Once reconstituted, the product may require refrigeration and use within a defined period.
Residual moisture is a key quality attribute for lyophilized products. Water that remains after secondary drying can affect chemical stability, cake structure, and shelf life. Karl Fischer titration is a common method for measuring water content in the dried solid. The target range varies by product, but many biologics are dried to between 0.5% and 3% water by weight. Acceptable limits are set during development and confirmed by stability studies.
Komagataella is a methylotrophic yeast within the order Pichiales. It was found in the 1960s as Pichia pastoris, with its feature of using methanol as a source of carbon and energy. In 1995, P. pastoris was reassigned into the sole representative of genus Komagataella, becoming Komagataella pastoris. In 2005, it was found that almost all strains used industrially and in labs are a separate species, K. phaffii. Later studies have further distinguished new species in this genus, resulting in a total of 7 recognized species. It is not uncommon to see the old name still in use in the context of protein production, as of 2023; in less formal use, the yeast may confusingly be referred to as pichia. After years of study, Komagataella is widely used in biochemical research and biotech industries. With strong potential for being an expression system for protein production, as well as being a model organism for genetic study, Komagataella phaffii has become important for biological research and biotech applications.
Methods incorporating chromatography generally begin with cryodepleted plasma undergoing buffer exchange via either diafiltration or buffer exchange chromatography, to prepare the plasma for following ion exchange chromatography steps. After ion exchange there are generally further chromatographic purification steps and buffer exchange. For further information see chromatography in blood processing.
The CJNG are fighting the Nueva Plaza Cartel for control of Guadalajara; La Unión Tepito for Mexico City; Los Viagras and La Familia Michoacana for the states of Michoacán and Guerrero; Los Zetas in the states of Veracruz and Puebla; Cártel del Noreste in Zacatecas; the Sinaloa Cartel in Baja California, Sonora, Ciudad Juárez, Zacatecas and Chiapas; as well as the Santa Rosa de Lima Cartel in Guanajuato. They have an alliance with the Cártel del Golfo in Zacatecas and La Línea in Juárez. CJNG is considered by the Mexican government to be one of the most dangerous criminal organizations in Mexico and the most powerful drug cartel in Mexico. It is also considered the cartel with the most paramilitary firepower. CJNG is heavily militarized and more violent than other criminal organizations. It has a special operations group known as the Grupo Élite for specific types of warfare. Its hitman training program is strict and professional. The cartel is best known for its fights against the Zetas and Templarios, it has fought La Resistencia for control of Aguililla, Michoacán, and its surrounding territories. In later time, it would be revealed that a major part of El Mencho's influence in the CJNG actually came through his marriage to Rosalinda González Valencia, herself highly involved in drug trafficking. From 2018 to 2020, the CJNG engaged in 298 reported acts of gang-related violence, more than any other cartel.
"On the basis of creativity, and research and development, JEOL (日本電子) positively challenges the world’s highest technology thus forever contributing to the progress in both science and human society through its products." In commemoration of JEOL's 20th anniversary, the Kazato Research Foundation was created to support electron microscopy research. Kenji Kazato retired as president of JEOL in 1975, but continued to act as an adviser to the company until his death in 2012. Kazuo Ito was JEOL's president from 1982 to 1987. The Pittcon Heritage Award was posthumously awarded to them in 2016 for their contributions to scientific instrumentation. In 2014, a STEM resolution of 45 pm with a 300 kV microscope was first demonstrated with the atomic transmission electron microscope JEM-ARM300F.
Sources: en.wikipedia.org
Osteolathyrism affects the bones and connecting tissues, instead of the nervous system. It is a skeletal disorder. It is caused by the toxin BAPN, which inhibits the copper-containing enzyme lysyl oxidase, responsible for cross-linking tropocollagen and proelastin. BAPN is also a metabolic product of a compound present in the sprouted seeds of grasspea, pea and lentil.
The balance-of-power system is discredited today. References to it, even by professional historians and international lawyers, commonly imply either that it was a system for war which repeatedly failed or that it was a system for making war which often succeeded in its purpose … During the period of its dominance as a European system, say, 1648 to 1918, its record in preventing war was certainly not striking. Indeed, it probably was itself responsible for starting more wars than it prevented. Former German Foreign Minister Joschka Fischer interpreted the core of the concept of Europe after 1945 as the rejection of the European balance-of-power principle and the hegemonic ambitions of individual states that had emerged following the Peace of Westphalia in 1648: "European integration was the response to centuries of a precarious balance of powers on this continent which again and again resulted in terrible hegemonic wars and culminated in the two World Wars between 1914 and 1945." Former US Secretary of Defense Dick Cheney expressed the same for Europe and other democracies: "It is not in our interest or those of the other democracies to return to earlier periods in which multiple military powers balanced one against another in what passed for security structures, while regional, or even global peace hung in the balance." NATO Secretary General, Manfred Wörner, outlined the European alternative at the end of the Cold War:
The central component of a mRNA vaccine is its mRNA construct. The in vitro transcribed mRNA is generated from an engineered plasmid DNA, which has an RNA polymerase promoter and sequence which corresponds to the mRNA construct. By combining T7 phage RNA polymerase and the plasmid DNA, the mRNA can be transcribed in the lab. Efficacy of the vaccine is dependent on the stability and structure of the designed mRNA. The in vitro transcribed mRNA has the same structural components as natural mRNA in eukaryotic cells. It has a 5' cap, a 5'-untranslated region (UTR) and 3'-UTR, an open reading frame (ORF), which encodes the relevant antigen, and a 3'-poly(A) tail. By modifying these different components of the synthetic mRNA, the stability and translational ability of the mRNA can be enhanced, and in turn, the efficacy of the vaccine improved. The mRNA can be improved by using synthetic 5'-cap analogues which enhance the stability and increase protein translation. Similarly, regulatory elements in the 5'-untranslated region and the 3'-untranslated region can be altered, and the length of the poly(A) tail optimized, to stabilize the mRNA and increase protein production. The mRNA nucleotides can be modified to both decrease innate immune activation and increase the mRNA's half-life in the host cell. The nucleic acid sequence and codon usage impacts protein translation. Enriching the sequence with guanine-cytosine content improves mRNA stability and half-life and, in turn, protein production.
Claims that growth hormone enhances physical performance are not supported by the scientific literature. Although the limited available evidence suggests that growth hormone increases lean body mass, it may not improve strength; in addition, it may worsen exercise capacity and increase adverse events. More research is needed to conclusively determine the effects of growth hormone on athletic performance.
Alexandre Marc Raymond was born on 22 January 1872 in Constantinople, in Turkey, then part of the Ottoman Empire. He was the son of Marc Raymond, architect, born in Constantinople in 1846, and Rose Valsamaki, Greek Orthodox, born in Cephalonia. In 1894, he began studying at Sanayi-i Nefise Mektebi (School of Fine Arts) in Constantinople where he was a student of Alexander Vallaury.
Sources: en.wikipedia.org
Lyophilization removes water by sublimation from a frozen material, while evaporation changes liquid water into vapor. The low-pressure freezing step avoids the liquid phase and can preserve heat-sensitive structures.
Vacuum lowers the pressure below the triple point of water, allowing ice to sublimate directly into vapor. It also helps remove water vapor from the product chamber and shortens primary drying.
Many aqueous solutions and suspensions can be freeze-dried, but some formulations collapse or do not form a stable cake. The process requires careful formulation and cycle development.
Lyophilized products should be stored in airtight containers, protected from moisture and light, at the temperature specified by the manufacturer. Many require refrigeration at 2–8 °C, while some need frozen storage. Always check the product label for specific conditions.