Residual moisture comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-05-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Quality control for lyophilized materials includes visual inspection of the cake, measurement of residual moisture, and tests for reconstitution time. An acceptable cake is typically uniform and may be slightly porous; shrinkage, meltback, or cracks can indicate process deviations. Analytical methods such as Karl Fischer titration, thermogravimetric analysis, and near-infrared spectroscopy quantify water content. Reconstitution time is recorded because a very slow or incomplete dissolution can signal collapse or aggregation. Stability studies compare samples stored under defined temperature and humidity conditions over months or years.
Regulatory expectations for lyophilized products focus on consistent manufacture and documented stability. Batches are often monitored for moisture, appearance, potency, and sterility where applicable. Process parameters such as shelf temperature, chamber pressure, and drying time are recorded and controlled within validated ranges. Open questions remain about how best to predict long-term stability from short accelerated studies, especially for complex biologics. Variations in freezing rate and ice crystal size can produce differences that are not always visible but may affect performance.
| Property | Value | Notes |
|---|---|---|
| Appearance | Porous solid cake | Typically white to off-white; varies with formulation |
| Reconstitution time | Seconds to several minutes | Depends on cake porosity and solute |
| Residual moisture | 0.5-3% w/w | Measured by Karl Fischer titration |
| Storage temperature | Room temperature to -20 °C | Product-specific; humidity-controlled |
| Common quality attribute | Cake elegance | Visual check for collapse, shrinkage, or meltback |
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.
Stability studies examine how temperature, humidity, and time influence a lyophilized product. Accelerated conditions provide early information about degradation pathways, while long-term studies support shelf-life claims. The glass transition temperature of the dried formulation can indicate its physical stability, and storage above this temperature may increase molecular mobility and lead to collapse or aggregation. Container closure integrity also matters because moisture or oxygen ingress can degrade the product, so vial stoppers and seals are part of the quality system.
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.
Storage conditions depend on the formulation and the intended shelf life. Many pharmaceutical and biological freeze-dried products are kept at 2–8 °C, while some stable foods and reagents tolerate room temperature. Others require −20 °C or colder to slow chemical degradation or aggregation. Protection from light and oxygen is common because oxidation can continue in the dry state. Stability studies usually monitor potency, appearance, moisture, and reconstitution time over months or years. Predictions from accelerated studies are useful but may not fully capture real-time changes.
Quality control for freeze-dried lots combines visual inspection with instrumental tests. Cake appearance, color, and shrinkage are recorded against a reference, while residual moisture is measured by Karl Fischer titration or loss on drying. Thermal analysis can reveal phase transitions and crystallization events, and X-ray diffraction distinguishes amorphous from crystalline solids. Microbiological tests and container closure integrity checks are also routine for sterile products. Analytical methods must be validated for the matrix, because excipients and low moisture can affect accuracy. Open questions include how best to predict long-term stability from short-term data.
Lyophilized solids are often hygroscopic, so handling occurs in controlled low-humidity areas or glove boxes when the material is exposed. Vials remain sealed with elastomeric stoppers and aluminum crimps until use, because airborne moisture can raise residual water and shorten shelf life. The porous cake is fragile and may crack, shrink, or powder during transport. Personnel typically avoid repeated warming and cooling of sealed units, which can draw moisture through closures. These practices aim to preserve the low water content achieved during drying.
=== Meiosis === Meiotic recombination in D. melanogaster appears to be employed in repairing damage in germ-line DNA as indicated by the findings that meiotic recombination is induced by the DNA damaging agents ultraviolet light and mitomycin C.
== Structure determination == Initial structures of eukaryotic ribosomes were determined by electron microscopy. First 3D structures were obtained at 30–40 Å resolution for yeast and mammalian ribosomes. Higher resolution structures of the yeast ribosome by cryo-electron microscopy allowed the identification of protein and RNA structural elements. Then structures at sub-nanometer resolution were obtained for complexes of ribosomes and factors involved in translation. After the determination of the first bacterial and archaeal ribosome structures at atomic resolution in the 1990s, it took another decade until in 2011, high resolution structures of eukaryotic ribosome were obtained by X-ray crystallography, mainly because of the difficulties in obtaining crystals of sufficient quality. The complete structure of a eukaryotic 40S ribosomal structure in Tetrahymena thermophila was published and described, as well as much about the 40S subunit's interaction with eIF1 during translation initiation. The eukaryotic 60S subunit structure was also determined from T. thermophila in complex with eIF6. The complete structure of the eukaryotic 80S ribosome from the yeast Saccharomyces cerevisiae was obtained by crystallography at 3.0 A resolution. These structures reveal the precise architecture of eukaryote-specific elements, their interaction with the universally conserved core, and all eukaryote-specific bridges between the two ribosomal subunits.
=== Campaigns === On November 8, 1980, Sanders announced his candidacy for mayor. He formally announced his campaign on December 16 at a City Hall press conference. Sanders selected Linda Niedweske as his campaign manager. The Citizens Party attempted to nominate Greg Guma for mayor, but Guma declined, saying it would be "difficult to run against another progressive candidate". Sanders had been convinced to run for the mayoralty by his close friend Richard Sugarman, an Orthodox Jewish professor of religious studies at the University of Vermont, who had shown him a ward-by-ward breakdown of the 1976 Vermont gubernatorial election, in which Sanders had run, that showed him receiving 12% of the vote in Burlington despite only getting 6% statewide. Sanders initially won the mayoral election by 22 votes against incumbent mayor Gordon Paquette, Richard Bove, and Joseph McGrath, but the margin was later reduced to 10 votes. Paquette did not contest the results of the recount. Paquette did not campaign or promote his candidacy since neither Sanders nor Bove was seen as a serious challenger. Sanders had not previously won an election. Paquette was also considered to have lost because he proposed an unpopular $0.65 per $100 raise in taxes that Sanders opposed. Sanders spent around $4,000 on his campaign. Sanders criticized the pro-development incumbent as an ally of prominent shopping center developer Antonio Pomerleau, while Paquette warned of ruin for Burlington if Sanders were elected.
== See also == The first man who was called a sans-culotte was the poet Nicolas Joseph Laurent Gilbert; also Robespierre and Pétion de Villeneuve were described as sans-culottes before the word came in vogue. Croppy Descamisado François Chabot Lazzaroni (Naples) Lumpenproletariat Pétroleuses
Sources: en.wikipedia.org
Partially hydrogenated vegetable oils were an increasingly significant part of the human diet for about 100 years, especially after 1950 as processed food rose in popularity. Animal-based fats were once the only trans fats consumed, but by far the largest amount of trans fat consumed today is created by the processed food industry as a side effect of partially hydrogenating unsaturated plant fats (generally vegetable oils). These partially hydrogenated fats have displaced natural solid fats and liquid oils in many areas, the most notable ones being in the fast food, snack food, fried food, and baked goods industries. Up to 45% of the total fat in those foods containing human-made trans fats formed by partially hydrogenating plant fats may be trans fat. An analysis of some industrialized foods in 2006 found up to 30% "trans fats" in artificial shortening, 10% in breads and cake products, 8% in cookies and crackers, 4% in salty snacks, 7% in cake frostings and sweets, and 26% in margarine and other processed spreads. Another 2010 analysis however found only 0.2% of trans fats in margarine and other processed spreads. Foods containing higher amounts of trans fat are associated with fast food restaurants. They are consumed in greater quantities by people who lack access to a diet consisting of fewer partially hydrogenated fats, or who often consume fast food. A diet high in trans fats can contribute to obesity, high blood pressure, and higher risk for heart disease. Trans fat is also implicated in Type 2 diabetes.
=== 16 September === The RSF carried out a drone attack that destroyed an ammunition dump within the garrison of the SAF's Fifth Division in El Obeid, resulting in an unspecified number of casualties.
Anderson University* Master of Medical Science (MMS), Pathologists’ Assistant Studies Carroll University** Master of Science in Pathologists' Assistant Studies Drexel University* Master of Science in Pathologists’ Assistant Studies Duke University* Master of Health Science Loma Linda University* Master’s Degree in Health Science, Pathologists’ Assistant Medical University of South Carolina*** Master of Science in Pathologists' Assistant Studies Program Old Dominion University EVMS* Master of Health Sciences, Pathologists’ Assistant Quinnipiac University* Master of Health Science Rosalind Franklin University* Master of Science in Pathologists' Assistant Studies Touro University* Master of Science Tulane University* Master of Science in Anatomic Pathology University of Alberta* MSc with Specialization in Pathologists' Assistant University of Calgary* Master of Pathologists' Assistant University of Jamestown*** Master of Health Science University of Maryland Baltimore* Master of Science in Pathology University of Tennessee Health Science Center* Master's of Health Science (MHS) in Pathologists' Assistants University of Texas Medical Branch at Galveston* Master of Pathologists’ Assistant University of Toledo* Master of Science in Biomedical Science University of Toronto* Master of Health Science Degree in Laboratory Medicine - Pathologists’ Assistant Field University of Washington*** Master of Science in Anatomic Pathology University of Western Ontario* Master of Clinical Science in Pathologists' Assistant Studies Wayne State University* Master of Science in Pathologists' Assistant Studies West Virginia University* Master of Health Science As of 2/20/2026, the programs above have the following status with the National Accrediting Agency for Clinical Laboratory Sciences: |*| Accredited |**| Serious Applicant Status |***| Submitted documentation to become accredited
Sources: en.wikipedia.org
In 1999, the High Court ruled in favor of three transgender women in the case North West Lancashire Health Authority v A, D and G. The transgender women sued the North West Lancashire Health Authority after being denied gender reassignment surgery from 1996 to 1997. The judgement was the first time that transgender surgical operations had been tested in an open court in the United Kingdom and was described by Stephen Lodge (the solicitor representing the three women) as a "landmark in the continuing struggle for legal recognition" of transgender rights in Britain. The ruling means that it is illegal for any health authority in England or Wales to put a blanket ban on gender-affirming surgery relating to transgender people. A 2013 survey of gender identity clinic services provided by the UK National Health Service (NHS) found that 94% of transgender people using the gender identity clinics were satisfied with their care and would recommend the clinics to a friend or family member. This study focused on transgender people using the NHS clinics and so was prone to survivorship bias, as those unhappy with the NHS service are less likely to use it. Despite this positive response, however, other National Health Service programs are lacking; almost a third of respondents reported inadequate psychiatric care in their local area. The options available from the National Health Service also vary with location; slightly differing protocols are used in England, Scotland, Wales and Northern Ireland. Protocols and available options differ widely outside of the UK.
Biological: In many soils, earthworms play a major role in the conversion of large pieces of organic matter into rich humus, thus improving soil fertility. This is achieved by the worm's actions (mainly of anecics) of pulling below the surface deposited organic matter such as leaf fall or manure, either for food or to plug its burrow. Once in the burrow, the worm will shred the leaf, partially digest it and mingle it with the earth. Worm casts (see bottom right) can contain 40 percent more humus than the top 9 inches (230 mm) of soil in which the worm is living.
Several predictions have been made regarding the exact location of the island of stability, though it is generally thought to center near copernicium and flerovium isotopes in the vicinity of the predicted closed neutron shell at N = 184. These models strongly suggest that the closed shell will confer further stability towards fission and alpha decay. While these effects are expected to be greatest near atomic number Z = 114 (flerovium) and N = 184, the region of increased stability is expected to encompass several neighboring elements, and there may also be additional islands of stability around heavier nuclei that are doubly magic (having magic numbers of both protons and neutrons). Estimates of the stability of the nuclides within the island are usually around a half-life of minutes or days; some optimists propose half-lives on the order of millions of years. Although the nuclear shell model predicting magic numbers has existed since the 1940s, the existence of long-lived superheavy nuclides has not been definitively demonstrated. Like the rest of the superheavy elements, the nuclides within the island of stability have never been found in nature; thus, they must be created artificially in a nuclear reaction to be studied. Scientists have not found a way to carry out such a reaction, for it is likely that new types of reactions will be needed to populate nuclei near the center of the island.
The notochord is the defining feature (synapomorphy) of chordates, and was present throughout life in many of the earliest chordates. Although the stomochord of hemichordates was once thought to be homologous or from a common lineal origin, it is now viewed as analogous, convergent, or from a different lineal origin. Pikaia appears to have a proto-notochord, and notochords are present in several basal chordates such as Haikouella, Haikouichthys, and Myllokunmingia, all from the Cambrian. The Ordovician oceans included many diverse species of Agnatha and early Gnathostomata which possessed notochords, either with attached bony elements or without, most notably the conodonts, placoderms, and ostracoderms. Even after the evolution of the vertebral column in chondrichthyes and osteichthyes, these taxa remained common and are well represented in the fossil record. Several species (see list below) have reverted to the primitive state, retaining the notochord into adulthood, though the reasons for this are not well understood. Scenarios for the evolutionary origin of the notochord were comprehensively reviewed by Annona, Holland, and D'Aniello (2015). They point out that, although many of these ideas have not been well supported by advances in molecular phylogenetics and developmental genetics, two of them have actually been revived under the stimulus of modern molecular approaches:
Sources: en.wikipedia.org
Karl Fischer titration is a common reference method that quantifies water by a chemical reaction. Thermogravimetric analysis can also estimate moisture by weight loss on heating. Method choice depends on sample size and whether other volatile substances are present.
Cake collapse often occurs when the product exceeds its collapse temperature during primary drying. The frozen matrix loses structure and the ice channels close. Optimizing formulation and cycle parameters helps avoid this defect.
No. Storage temperature depends on the stability of the dried material. Some products are stable at room temperature, while others require refrigeration or freezing. Container integrity and moisture barriers also affect shelf life.
Most are held in sealed containers at controlled temperatures, often 2–8 °C, while some require frozen storage. Protection from moisture and light helps preserve the dry matrix. Exact conditions are set by the manufacturer or study protocol.