The short version of freeze-thaw fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-04-07. Anything still debated is marked as such rather than presented as settled.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
| Property | Value | Notes |
|---|---|---|
| Typical purity | ≥95% by HPLC | Research-grade material |
| Detection wavelength | 214 nm | Peptide bond absorbance |
| Reconstitution medium | Sterile water or saline | Prepare fresh or aliquot immediately |
| Storage (solution) | -80 °C, single-use aliquots | Avoid repeated freeze-thaw cycles |
| Common salt form | Acetate or trifluoroacetate | Affects mass and solubility |
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
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.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Chymosin or rennin is a protease found in rennet. It is an aspartic endopeptidase belonging to MEROPS A1 family. It is produced by newborn ruminant animals in the lining of the abomasum to curdle the milk they ingest, allowing a longer residence in the bowels and better absorption. It is widely used in the production of cheese. Historically, chymosin was obtained by extracting it from the stomachs of slaughtered calves. Today, most commercial chymosin used in cheese production is produced recombinantly in Escherichia coli, Aspergillus niger var. awamori, and Kluyveromyces lactis.
He also opposes the Trans-Pacific Partnership, which he says was "written by corporate America and the pharmaceutical industry and Wall Street." On May 1, 2019, he tweeted: "Since the China trade deal I voted against, America has lost over three million manufacturing jobs. It's wrong to pretend that China isn't one of our major economic competitors." Sanders also strongly opposes outsourcing American jobs. During discussions of the United States Innovation and Competition Act, which was to be used to fund the manufacture of semiconductors amid a shortage, he proposed a measure to ensure the companies the bill funded could not outsource their jobs. The proposed measure would also block the companies from forbidding their employees to unionize. Sanders's proposal was voted down by most Democrats and all Republicans in the Senate. Ahead of the 2022 midterms, Sanders said he wants the Democratic Party to focus more on supporting unionization: "I think we should move to a system where, if 50% of the workers in a bargaining unit plus one vote to form a union, they have a union.
Ammonium sulfate (American English and international scientific usage; ammonium sulphate in British English); [NH4]2SO4, is an inorganic salt with a number of commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen and 24% sulfur.
HCO2CH3 + H2O → HCOOH + CH3OH Efficient hydrolysis of methyl formate requires a large excess of water. Some routes proceed indirectly by first treating the methyl formate with ammonia to give formamide, which is then hydrolyzed with sulfuric acid:
Despite a rally on January 15 on news of lower unemployment insurance claims, the Dow Jones, the Nasdaq, and the S&P 500 closed just below their opening bell valuations on January 16 and finished the week at a loss upon news that Trump suggested that the most likely candidate to replace Powell as Federal Reserve Chair had changed and threats by Trump to impose import tariffs on countries that oppose the United States acquiring Greenland. Over the same two days, the dollar strengthened, gold prices fell, and yields on 2-year and 10-year Treasury notes rose. As indicated by the weakening of the U.S. dollar on its exchange rates, the precious metals price increases, and the rising yields and steepening yield curve on Treasury notes in the bond market over the week following Powell's announcement, market analysts have observed that the investigation and potential loss of the Federal Reserve's independence (along with the geopolitical risks) indicates higher long-term inflation expectations by investors and has reinforced interest for greater global diversification of investment holdings and away from U.S. assets. JPMorgan Chase CEO Jamie Dimon and BNY CEO Robin Vince both criticized the investigation, arguing that undermining the Federal Reserve's independence would raise inflation expectations, increase interest rates in the long-term, and undermine the functioning of the bond market.
Sources: en.wikipedia.org
== Properties == While most bacteriocins generally inhibit only closely related species, nisin is a rare example of a "broad-spectrum" bacteriocin effective against many Gram-positive organisms, including lactic acid bacteria (commonly associated with avoiding food spoilage), Listeria monocytogenes (a known pathogen), Staphylococcus aureus, Bacillus cereus, Clostridium botulinum, etc. It is also particularly effective against spores. Gram-negative bacteria are protected by their outer membrane but may become susceptible to nisin action after a heat shock or when this is coupled with the chelator EDTA. When used in combination with EDTA, nisin can inhibit E. coli O157:H7 and Salmonella enterica. Nisin, as a class I bacteriocin, is very stable at acidic pHs and is more heat stable at lower pHs. The mode of action of Nisin against pathogens such as Listeria monocytogenes is to dissipate the membrane potential and pH gradient. Nisin is soluble in water and effective at levels nearing the parts-per-billion range. Nisin concentration can be measured using various techniques such as chromatography or by a simple agar diffusion bioassay.
== Business == Kinohimitsu has a distribution network of more than 6,000 points of sales in Asia, namely China, Singapore, Malaysia, Vietnam, Thailand, Cambodia and Indonesia. Kinohimitsu's products are sold in pharmacies, supermarkets and convenience stores. In 2014, Kinohimitsu opened its first beauty counter in Singapore at OG Orchard Point.
=== Ethnicity === The total prevalence of glaucoma is about the same in North America and Asia, but the prevalence of angle-closure glaucoma is four times higher in Asia than in North America. In the United States, glaucoma is more common in African Americans, Latinos, and Asian-Americans.
=== Medical === Supplemental HMB has been used in clinical trials as a treatment for preserving lean body mass in muscle wasting conditions, particularly sarcopenia, and has been studied in clinical trials as an adjunct therapy in conjunction with resistance exercise. Based upon two medical reviews and a meta-analysis of seven randomized controlled trials, HMB supplementation can preserve or increase lean muscle mass and muscle strength in sarcopenic older adults. HMB does not appear to significantly affect fat mass in older adults. Preliminary clinical evidence suggests that HMB supplementation may also prevent muscle atrophy during bed rest. A growing body of evidence supports the efficacy of HMB in nutritional support for reducing, or even reversing, the loss of muscle mass, muscle function, and muscle strength that occurs in hypercatabolic disease states such as cancer cachexia; consequently, the authors of two 2016 reviews of the clinical evidence recommended that the prevention and treatment of sarcopenia and muscle wasting in general include supplementation with HMB, regular resistance exercise, and consumption of a high-protein diet. Clinical trials that used HMB for the treatment of muscle wasting have involved the administration of 3 grams of HMB per day under different dosing regimens.
== Clinical development == The precursor molecule to BOLD-100, KP1339 was tested in a Phase 1 monotherapy clinical trial in heavily pretreated patients with advanced cancers. In this dose escalation study, KP1339 was administered to 46 patients with doses ranging from 20 mg/m2 to 780 mg/m2. KP1339 was well tolerated, with the treatment-emergent adverse events occurring in >20% of patients being nausea, fatigue, vomiting, anaemia and dehydration. These adverse events were mainly grade 2 or lower. In the 38 efficacy-evaluable patients, nine patients achieved stable disease and 1 patient had a durable partial response. 625 mg/m2 was determined to be the recommended Phase 2 dose. BOLD-100 is being tested in a Phase 1b/2a clinical trial in combination with the chemotherapy regimen FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) for the treatment of gastrointestinal cancers, including gastric, pancreatic, colon and bile duct cancer. This trial includes a dose escalation phase followed by a cohort expansion with 117 patients enrolled. Interim data presented at ASCO GI in January 2024 showed that BOLD-100 + FOLFOX was active and well-tolerated treatment in a heavily pre-treated Stage IV mCRC study population with 36 patients. Progression Free Survival, Overall Survival, and Objective Response Rate demonstrate significant clinical benefit and improvement over the currently available therapies, with minimal treatment emergent neuropathy or significant toxicities.
Sources: en.wikipedia.org
Jaerae-hansik-ganjang (재래한식간장, "traditional Korean-style soy sauce") – made with traditional style meju and brine. Gaeryang-hansik-ganjang (개량한식간장, "modernized Korean-style soy sauce") – made with nontraditional meju (which can be made of regular soybean, rice, barley, wheat, or soybean meal, and ripened using traditional method or Aspergillus) and brine.
Quicksand is a shear thinning non-Newtonian colloid that gains viscosity at rest. Quicksand's non-Newtonian properties can be observed when it experiences a slight shock (for example, when someone walks on it or agitates it with a stick), shifting between its gel and sol phase and seemingly liquefying, causing objects on the surface of the quicksand to sink.
Despite their ethnic diversity and linguistic distinctions, the various Quechua ethnic groups have numerous cultural characteristics in common. They also share many of these with the Aymara or other Indigenous peoples of the central Andes. Traditionally, Quechua identity is locally oriented and inseparably linked in each case with the established economic system. It is based on agriculture in the lower altitude regions, and on pastoral farming in the higher regions of the Puna. The typical Andean community extends over several altitude ranges and thus includes the cultivation of a variety of arable crops and/or livestock. The land is usually owned by the local community (ayllu) and is either cultivated jointly or redistributed annually.
planifolia seeds this way are Eulaema polychroma and Scaptotrigona subobscuripennis. Seeds being distributed by bees is a rare behavior and has only been documented in three species of tropical trees previously, the cadaghi (Corymbia torelliana), Coussapoa asperifolia subsp. magnifolia, and Zygia racemosa. Both rodents and marsupials are confirmed to consume fallen pods on the forest floor. Specific species observed eating the pods include Tome's spiny rat (Proechimys semispinosus) and the common opossum (Didelphis marsupialis). Further experiments by a team led by Dr. Adam Karremans showed that the seeds remained viable after being passed through the mammalian gut, but it did not increase or decrease germination significantly.
Sources: en.wikipedia.org
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase liquid chromatography establishes purity, while mass spectrometry confirms molecular mass. The two techniques are normally used together. Retention time alone is not sufficient evidence of identity.
Different counterions change the mass per unit of peptide and can shift chromatographic behavior. Two samples of equal stated purity may therefore not be directly comparable. Reports should specify the counterion whenever quantitative comparisons are made.
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.