A practical reference on Moisture sorption: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-15 and is reviewed periodically as new material appears.
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.
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.
Quality control for lyophilized products focuses on appearance, moisture level, reconstitution time, and structural integrity. A cake should be uniform, intact, and free of meltback or collapse. Moisture level is measured by Karl Fischer titration or thermogravimetric analysis. Reconstitution time reflects pore structure and formulation. Visual inspection and vial integrity checks detect cracks, stopper defects, or particulate matter. These checks are often performed on samples from each batch. They help confirm that the drying cycle performed as intended.
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.
| Property | Value | Notes |
|---|---|---|
| Primary phase change | Sublimation | Ice changes directly to vapor under reduced pressure |
| Typical chamber pressure | 0.01–0.5 mbar (1–50 Pa) | Below the triple point of water; product-specific |
| Typical product temperature during primary drying | −40 °C to −10 °C | Kept below collapse temperature |
| Typical residual moisture | 0.5–3% w/w | Target range varies by formulation and use |
| Common synonyms | Freeze-drying; lyophilisation | Lyophilization is the US spelling |
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.
A formulation often contains excipients that protect the active ingredient during freezing and drying. Bulking agents provide structure, while lyoprotectants stabilize sensitive molecules. The freezing step can produce ice crystals whose size and distribution affect the drying rate, and cycle design includes freezing, annealing, and drying phases. If the product temperature rises above a critical value, the cake may collapse or lose its porous structure. Successful lyophilization therefore depends on the interaction between formulation, equipment, and cycle design.
After lyophilization, the dried product is often sealed under vacuum or an inert gas to limit moisture and oxygen exposure. Vials, stoppers, and seals must maintain their barrier throughout shelf life. Storage temperature depends on product sensitivity: some cakes tolerate controlled room temperature, while labile biologics require refrigeration. Humidity is a critical variable because dried cakes are hygroscopic and can absorb water when exposed to air. Handling procedures therefore limit open-vial time and use desiccated environments for sampling.
Quality control for lyophilized materials examines appearance, reconstitution time, residual moisture, and mechanical integrity. An acceptable cake is usually uniform and porous, though appearance alone does not prove stability. Karl Fischer titration is a common method for water content, while differential scanning calorimetry can reveal glass transition events. Stability studies track potency, aggregation, and moisture over time under defined temperature and humidity conditions. Specifications are product-specific and may include sterility and endotoxin tests for sterile preparations.
The San Francisco 49ers defeated the Cincinnati Bengals 26 to 21, to win Super Bowl XVI at the Pontiac Silverdome in Pontiac, Michigan. The telecast of the game continues to hold the record for highest television ratings for a Super Bowl broadcast, with a 49.1 rating and a 73 share of the audience, with almost three out of four households with television watching the game. U.S. astronomer Edward L. G. Bowell discovered three asteroids in the same day, designating the 9 miles (14 km) minor planet as 3131 Mason-Dixon. The name honored English astronomers and surveyors Charles Mason and Jeremiah Dixon for whom the "Mason–Dixon line" boundary between U.S. states was named. On the same day, Bowell discovered 3749 Balam, which has two minor-planet moons revolving around it, and 2905 Plaskett. Born: Jamie "Killer" Lyon, Australian professional rugby league centre, selected as the National Rugby League's Dally M Medal winner for centre of the year in 2010, 2011, 2013 and 2014, and Centre of the Year by the Rugby League International Federation in 2011 and 2013; in Narrabri, New South Wales Died: Alfredo Ovando Candia, 65, President of Bolivia from 1969 to 1970 Karol Borsuk, 76, Polish mathematician and topologist known for the theories of absolute retracts (ARs) and absolute neighborhood retracts (ANRs), as well as the Borsuk-Spanier cohomotopy groups, Borsuk's conjecture, the Borsuk–Ulam theorem and the Bing–Borsuk conjecture. Fernando Sánchez Polack, 61, Spanish film actor with appearances in 110 films, primarily Westerns, from 1959 to 1992, died from a cardiac arrest.
Obesity in Brazil is a major public health challenge and one of the leading risk factors for non-communicable diseases in the country. Brazil is the largest country in South America and the fifth most populous in the world, with approximately 215 million inhabitants. Since the early 21st century, Brazil has experienced a substantial increase in obesity and overweight prevalence among adults, reflecting changes in dietary patterns, physical activity levels, urbanisation, and socioeconomic conditions. According to data from the Brazilian Ministry of Health's Vigilância de Fatores de Risco e Proteção para Doenças Crônicas por Inquérito Telefônico (transl. Surveillance of Risk and Protective Factors for Chronic Diseases via Telephone Survey) (Vigitel), obesity prevalence among adults living in the 26 Brazilian state capitals and the Federal District more than doubled between 2006 and 2024.
Acetaminophen (or paracetamol) is an analgesic medication that can affect the liver when administered in high doses. Acetaminophen is predominantly conjugated into glucuronate and sulfate moieties by Phase II metabolism. A small percentage is metabolized by the cytochrome P450 pathway to a toxic metabolite, NAPQI. NAPQI is conjugated by glutathione to non-toxic cysteine and mercapturic acid moieties. In cases of acetaminophen toxicity, the Phase II conjugation enzymes are saturated, and a higher fraction is converted to NAPQI. The conjugation of NAPQI to glutathione occurs until glutathione is depleted from hepatic reserves, after which the toxic NAPQI accumulates and causes damage to the hepatocytes. This occurs primarily in areas of the liver that are relatively poorly perfused with oxygen, or furthest away from the hepatic artery, termed Zone 3. Acetaminophen overdose is associated with Zone 3 necrosis, to the point that acute liver failure may result. The King's College Criteria identify two groups of patients that have a poor prognosis with acetaminophen induced liver failure:
The oxidative environment of the periplasm contains Dsb (disulfide bond formation) proteins that catalyze such post-translational modifications, and therefore play an important role in establishing virulence factor tertiary and quaternary structure essential for proper protein function. In addition to Dsb proteins found in the periplasm, motility organelles such as the flagellum are also essential for host infection. The flagellum is rooted in the periplasm and is stabilized by interaction with periplasmic structural components, and is therefore another pathogenesis-related target for antimicrobial agents. During infection of a host, the cell of a bacterium is subject to many turbulent environmental conditions, which highlights the importance of the structural integrity afforded by the periplasm. In particular, peptidoglycan synthesis is vital to cell wall production, and inhibitors of peptidoglycan synthesis have been of clinical interest for targeting bacteria for many decades. Furthermore, the periplasm is also relevant to clinical developments by way of its role in mediating the uptake of transforming DNA.
Malaysian 7-Eleven stores are owned by 7-Eleven Malaysia Sdn. Bhd., which operates 3,225 stores nationwide. 7-Eleven in Malaysia was incorporated on June 4, 1984, as a joint venture of Jardine Matheson, Innovest and Antah Holdings group. The first 7-Eleven store was opened in October 1984, in Jalan Bukit Bintang, Kuala Lumpur. Its 2,000th outlet at Jalan Klang Lama opened in July 2016.
Sources: en.wikipedia.org
Constitutionally, the USSR was a federation of constituent Union Republics, which were either unitary states, such as Ukraine or Byelorussia (SSRs), or federations, such as Russia or Transcaucasia (SFSRs), all four being the founding republics who signed the Treaty on the Creation of the USSR in December 1922. In 1924, during the national delimitation in Central Asia, Uzbekistan and Turkmenistan were formed from parts of Russia's Turkestan ASSR and two Soviet dependencies, the Khorezm and Bukharan PSPs. In 1929, Tajikistan was split off from the Uzbekistan SSR. With the constitution of 1936, the Transcaucasian SFSR was dissolved, resulting in its constituent republics of Armenia, Georgia and Azerbaijan being elevated to Union Republics, while Kazakhstan and Kirghizia were split off from the Russian SFSR, resulting in the same status. In August 1940, Moldavia was formed from parts of Ukraine and Soviet-occupied Bessarabia, and Ukrainian SSR. Estonia, Latvia and Lithuania were also annexed by the Soviet Union and turned into SSRs, which was not recognized by most of the international community and was considered an illegal occupation. After the Soviet invasion of Finland, the Karelo-Finnish SSR was formed on annexed territory as a Union Republic in March 1940 and then incorporated into Russia as the Karelian ASSR in 1956. Between July 1956 and September 1991, there were 15 union republics (see map below).
== See also == Clinical laboratory scientist Healthcare scientist List of publications in physics: Biophysics and medical physics Modernising Scientific Careers Physicist European Federation of Organisations for Medical Physics (EFOMP)
Moreover, manual analysis of the proposed candidates and their MS/MS spectra was still necessary to verify structures, which requires laborious technical analysis. To enable larger scale screenings, the software will require more advanced compound filtering and candidate ranking. Overall, the system is intended to facilitate the identification of inhibitors for challenging enzymatic targets while reducing the amount of synthetic efforts required. Its potential applications include inhibitor discovery in both academic and industrial research settings.
Frugivorous bats lack that ability and have kidneys adapted for electrolyte retention due to their low-electrolyte diet; their kidneys accordingly have a thick cortex and very short conical papillae. Flying gives bats relatively high metabolism, which increases respiratory water loss. Lipids known as cerebrosides retain water in cold temperatures but allow for evaporation through the skin in hot temperatures to cool them. Water helps maintain the ionic balance in their blood, thermoregulation system and urinary and waste system. They are also susceptible to blood urea poisoning if they do not receive enough fluid. The structure of the uterine system in female bats can vary by species, with some having two uterine horns while others have a single mainline chamber.
Sources: en.wikipedia.org
== Autologous grafts == Autologous grafts are used to transfer tissue from one site to another on the same body. The use of autologous grafts prevents transplantation rejection reactions. Grafts used for oral reconstruction are preferably taken from the oral cavity itself (such as gingival and palatal grafts). However, their limited availability and small size leads to the use of either skin transplants or intestinal mucosa to be able to cover bigger defects. Other than tissue shortage, donor site morbidity is a common problem that may occur when using autologous grafts. When tissue is obtained from somewhere other than the oral cavity (such as the intestine or skin) there is a risk of the graft not being able to lose its original donor tissue characteristics. For example, skin grafts are often taken from the radial forearm or lateral upper arm when covering more extensive defects. A positive aspect of using skin grafts is the large availability of skin. However, skin grafts differ from oral mucosa in: consistency, color and keratinization pattern. The transplanted skin graft often continues to grow hair in the oral cavity.
=== Video games === The term applies to video games that persuade consumers to buy a particular video game console or accessory, by virtue of platform exclusivity. Such a game is also called a "system seller".
Websites dedicated to erotic or pornographic AI-generated content primarily cater to an audience seeking personalized material. These platforms allow generating explicit content using various AI models or viewing content created by others. Tags are frequently used to refine search results, allowing users to find highly specific content by selecting attributes such as body type, facial features, sexual fetishes, general art styles, ranging from anime to realism, as well as art styles of specific artists. Many AI porn sites feature extensive image libraries and continuous feeds of user-generated content, with the ability to modify already generated images. Generative AI pornography has also been reported to reproduce stereotypes and unrealistic depictions of LGBTQ people. There are concerns that using existing pornography as training data may reinforce harmful stereotypes and fetishization.
Sources: en.wikipedia.org
Lyophilization relies on sublimation, so water moves from solid ice to vapor without becoming liquid. The material is frozen, pressure is reduced, and controlled heat is supplied. Vapor is captured on a cold condenser, leaving a dry porous solid.
The process has three main stages: freezing, primary drying, and secondary drying. Freezing sets the ice structure, primary drying removes free ice, and secondary drying removes bound water. Each stage uses specific temperature, pressure, and time settings.
No, it is a drying method rather than a sterilization method. Removing water can limit microbial growth, but it does not reliably kill microorganisms. Sterility must come from separate steps such as filtration, heat treatment, or aseptic processing.
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.