If you have been reading about intranasal delivery and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-03-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffers |
| Typical storage temperature | -20 °C | Dry, desiccated, protected from light |
| Typical analytical method | RP-HPLC with UV detection | Often paired with LC-MS |
| Water content | Reported as Karl Fischer value | Freeze-dried material is hygroscopic |
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
== Reception == Justin Chang gave the film a positive review in Variety, describing it as "a precocious if rather precious debut feature for writer-director Jennifer Phang", praising the film's computer generated effects and the representation of Tim and Pam's relationship through Aasulv Wolf Austad's cinematography, comparing it to the works of Apichatpong Weerasethakul. The Hollywood Reporter was similarly positive, criticizing the film as suffering from budget restraints, but praising Phang's depiction of the two households for capturing dark humor as well as "real pain and anguish", in addition to praising Alexander Agate's performance.
Each part of the digestive system is subject to a wide range of disorders many of which can be congenital. Mouth diseases can also be caused by pathogenic bacteria, viruses, fungi and as a side effect of some medications. Mouth diseases include tongue diseases and salivary gland diseases. A common gum disease in the mouth is gingivitis which is caused by bacteria in plaque. The most common viral infection of the mouth is gingivostomatitis caused by herpes simplex. A common fungal infection is candidiasis commonly known as thrush which affects the mucous membranes of the mouth. There are a number of esophageal diseases such as the development of Schatzki rings that can restrict the passageway, causing difficulties in swallowing. They can also completely block the esophagus. Stomach diseases are often chronic conditions and include gastroparesis, gastritis, and peptic ulcers. A number of problems including malnutrition and anemia can arise from malabsorption, the abnormal absorption of nutrients in the GI tract. Malabsorption can have many causes ranging from infection, to enzyme deficiencies such as exocrine pancreatic insufficiency. It can also arise as a result of other gastrointestinal diseases such as coeliac disease. Coeliac disease is an autoimmune disorder of the small intestine. This can cause vitamin deficiencies due to the improper absorption of nutrients in the small intestine. The small intestine can also be obstructed by a volvulus, a loop of intestine that becomes twisted enclosing its attached mesentery. This can cause mesenteric ischemia if severe enough.
The Battle of the Philippine Sea was a major naval battle of World War II on 19–20 June 1944 that eliminated the Imperial Japanese Navy's ability to conduct large-scale carrier actions. It took place during the United States' amphibious reconquest of the Mariana Islands during the Pacific War. The battle was the last of five major "carrier-versus-carrier" engagements between American and Japanese naval forces, and pitted elements of the United States Navy's Fifth Fleet against ships and aircraft of the Imperial Japanese Navy's Mobile Fleet and nearby island garrisons. The battle was the largest carrier-to-carrier engagement in history, involving 24 aircraft carriers, deploying roughly 1,350 carrier-based aircraft. The aerial part of the battle was nicknamed the Great Marianas Turkey Shoot by American aviators for the severely disproportional loss ratio inflicted upon Japanese aircraft by American pilots and anti-aircraft gunners. During a debriefing after the first two air battles, a pilot from USS Lexington remarked "Why, hell, it was just like an old-time turkey shoot down home!" The outcome is generally attributed to a wealth of highly trained American pilots with superior tactics and numerical superiority, and new anti-aircraft ship defensive technology (including the top-secret anti-aircraft proximity fuze), versus the Japanese use of replacement pilots with not enough flight hours in training and little to no combat experience.
Sources: en.wikipedia.org
The primers used must be specific to the targeted sequences in the DNA of a virus, and PCR can be used for diagnostic analyses or DNA sequencing of the viral genome. The high sensitivity of PCR permits virus detection soon after infection and even before the onset of disease. Such early detection may give physicians a significant lead time in treatment. The amount of virus ("viral load") in a patient can also be quantified by PCR-based DNA quantitation techniques (see below). A variant of PCR (RT-PCR) is used for detecting viral RNA rather than DNA: in this test the enzyme reverse transcriptase is used to generate a DNA sequence that matches the viral RNA; this DNA is then amplified as per the usual PCR method. RT-PCR is widely used to detect the SARS-CoV-2 viral genome. Diseases such as pertussis (or whooping cough) are caused by the bacteria Bordetella pertussis. This bacteria is marked by a serious acute respiratory infection that affects various animals and humans and has led to the deaths of many young children. The pertussis toxin is a protein exotoxin that binds to cell receptors by two dimers and reacts with different cell types such as T lymphocytes which play a role in cell immunity. PCR is an important testing tool that can detect sequences within the gene for the pertussis toxin. Because PCR has a high sensitivity for the toxin and a rapid turnaround time, it is very efficient for diagnosing pertussis when compared to culture.
Awake – a short-lived artificial orange juice formulated by General Foods Corporation and introduced in 1964. It was a predecessor to Tang. Instant breakfast Chocolate drinks Hot chocolate Swiss Miss – hot chocolate Milo – can be prepared cold or hot Nesquik Ovaltine Instant coffee Drink mix Freeze-dried fruit juices Powdered milk – in a 1986 session in Moscow, Russia, the International Dairy Federation defined instant skim milk powder as qualifying for the term "instant" when no more than fifteen seconds are required for all lumps to disappear when the powder is mixed with water and stirred. Coconut milk powder Tang – a fruit-flavored drink that was originally formulated by General Foods Corporation food scientist William A. Mitchell in 1957. It was first marketed in powdered form in 1959. The Tang brand is owned by Mondelēz International. Instant tea Instant milk tea – a mass-produced instant powder
When fellow guard Bosch dissents, Barris pressures him to continue. Travis discovers that Benjy, now severely ill, concealed his need for insulin, believing he could cure his diabetes merely through dieting. Bosche tries to help find Benjy's insulin, but is caught by other guards. Barris provides Benjy's insulin, but later has all the guards beat Bosche severely and orders Travis to clean the prison toilets. When Travis taunts Barris, the guards respond by shoving his head into the toilet, nearly drowning him. One morning during roll call, Travis removes his shirt as a sign of protest, followed by the other prisoners. He climbs up to one of the cameras and demands they be released, but the guards choke him. When Benjy tries to defend Travis, Barris bludgeons him. Guards lock Travis into an old boiler pipe overnight, attack the remaining prisoners, and handcuff each man across the cell doors. While locked in the boiler, Travis discovers a hidden infrared camera. As his despondency turns to anger, he manages to escape and interrupts a guard’s attempt to rape a prisoner. The intended victim and Travis beat the guard and knock him out before freeing the other prisoners. Finding Benjy dead from his head injury, Travis leads an assault against the guards, chasing them through the building. As the remaining guards try to lift the garage door to escape, Barris tries to keep them in, unwilling to forfeit his power. A vicious brawl ensues with the prisoners overwhelming the guards.
=== Fermentation-produced chymosin === Because of the above imperfections of microbial and animal rennets, many producers sought other replacements of rennet. With genetic engineering it became possible to isolate rennet genes from animals and introduce them into certain bacteria, fungi, or yeasts to make them produce recombinant chymosin during fermentation. The genetically modified microorganism is killed after fermentation and chymosin isolated from the fermentation broth, so that the fermentation-produced chymosin (FPC) used by cheese producers does not contain a GMO or any GMO DNA. FPC is identical to chymosin made by an animal, but is produced in a more efficient way. FPC products have been on the market since 1990 and, because the quantity needed per unit of milk can be standardized, are commercially viable alternatives to crude animal or plant rennets, as well as generally preferred to them in industrial production. Originally created by biotechnology company Pfizer, FPC was the first artificially-produced enzyme to be registered and allowed by the US Food and Drug Administration. In 1999, about 60% of US hard cheeses were made with FPC, which thereafter made up to 80% of the global market share for rennet. By 2017, FPC had 90% of the global market share for rennet. By 2021, animal rennet still found use in some traditional or designated European cheeses but FPC covered 80-90% of the market in the US and UK. The most widely used FPC is produced either by the fungus Aspergillus niger and commercialized under the trademark CHY-MAX by the Danish company Chr.
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.
Dry lyophilised powder is generally kept at minus twenty degrees Celsius, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they encourage aggregation and moisture uptake. Solutions are less stable than the solid form and degrade faster at room temperature.
A certificate documents what the supplier measured, not what an independent party confirmed. Methods, instruments and acceptance criteria can differ between suppliers. Third-party testing is the usual way to resolve discrepancies.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.