counterion 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 2025-11-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
The molecule is a short, linear, hydrophilic peptide that dissolves readily in water or aqueous buffer. Its principal chemical liabilities are hydrolytic rather than oxidative, since it contains no cysteine, methionine, or tryptophan residues. The aspartate–glycine step is a recognised site for aspartimide formation under mildly acidic or basic conditions, generating isoaspartate and succinimide-related products over time. Desiccated lyophilised powder held at −20 °C is comparatively stable, whereas dilute solutions degrade faster and are best frozen as single-use aliquots rather than thawed repeatedly.
No pharmacopoeial monograph exists for this peptide, so quality rests on the supplier's internal specifications and on whatever independent testing a purchaser arranges. Certificates of analysis differ widely in which tests they report and in the limits applied. The counter-ion introduced during purification, commonly acetate or trifluoroacetate, changes the net peptide content of a given mass of powder, so two samples of equal weight may not contain equal amounts of the active sequence. Third-party laboratories can verify purity, identity, residual solvents, and counter-ion content for a fee, which makes documentation more informative than labelling.
Verification of a sample usually begins with reversed-phase high-performance liquid chromatography, which resolves the peptide from truncated sequences and other impurities and expresses purity as a percentage of total peak area. Mass spectrometry by electrospray ionisation or matrix-assisted laser desorption supplies an independent check, because the measured mass can be compared against the theoretical value for AEDG. Amino acid analysis or tandem mass spectrometry sequencing can confirm residue order. Each of these methods answers a different question: a purity figure does not establish identity, and an identity match does not establish how much of the material is intact peptide.
The most frequently cited laboratory finding is that AEDG increased telomerase activity and extended telomere length in cultured human somatic cells. That work used fetal fibroblast strains and reported changes in enzyme activity alongside altered division counts. Replication by unrelated groups has been limited, and the published record is largely a single-laboratory series rather than a multi-centre programme. The result supports a hypothesis about peptide influence on gene expression in cell culture; it does not by itself establish an effect on telomere length in living animals or in people.
Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.
No national medicines regulator has approved epitalon as a therapeutic product. It is generally distributed as a research chemical, and in some jurisdictions selling peptides for human consumption without approval is restricted or prohibited. Certificates of analysis accompanying commercial material vary in which tests are performed, and independent verification of identity and purity is uncommon. Statements about anti-ageing or disease-prevention benefits on vendor pages are marketing claims rather than regulatory findings, a distinction that shapes how the compound is discussed in scientific and popular sources alike.
| Property | Value | Notes |
|---|---|---|
| Identity confirmation | Electrospray or MALDI mass spectrometry | Observed mass compared with theoretical 390.35 Da |
| Purity specification | 95 percent or greater by RP-HPLC | Common convention for research-grade peptide |
| Counter-ion | Acetate or trifluoroacetate | Affects net peptide content of a weighed sample |
| Solution storage | −80 °C as single-use aliquots | Repeated freeze–thaw cycles accelerate loss |
| Main degradation route | Aspartimide formation at Asp-Gly | Produces isoaspartate and related species |
Stability depends strongly on pH, temperature and the presence of oxygen and trace metals. Cleavage of the backbone proceeds faster under neutral to alkaline conditions, whereas acidic solutions tend to slow that reaction. The aspartate and glutamate side chains can undergo deamidation or imide formation over time, generating closely related impurities. Published stability data specific to epitalon are sparse, so the usable life of a given solution is best regarded as an open question that depends on buffer composition, concentration and storage temperature.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
Laboratory handling begins with dissolution of the lyophilized powder in water or a suitable aqueous buffer. The dry solid is the more stable form, so stock solutions are generally prepared only when required and kept cold afterwards. Repeated freezing and thawing of a solution is avoided because it encourages aggregation and gradual loss of the intact chain. Diluents and containers are selected to limit adsorption of a short peptide onto plastic surfaces and to reduce microbial growth in aqueous preparations.
Identity and purity are established with reversed-phase high-performance liquid chromatography and mass spectrometry. The chromatogram shows the main peak and any truncated or oxidised by-products, while the mass spectrum confirms the expected 390 dalton mass. Amino acid analysis can corroborate composition when a sample's origin is uncertain. Counterion content, particularly residual trifluoroacetate from purification, is frequently reported alongside purity because it shifts the net mass of the solid.
Reference material is normally supplied as a lyophilised powder in a sealed vial. Product literature typically recommends storage at minus twenty degrees Celsius or colder, protected from light and moisture. Freeze-thaw cycling is usually avoided because repeated condensation can introduce water into the vial. Working solutions are commonly prepared fresh, aliquoted, and kept cold for short periods rather than stored at ambient temperature. Labelling the date of opening helps track how long a vial has been in use.
Solubility is high in water, phosphate-buffered saline and normal saline, a pattern that follows from the two acidic residues in the chain. The peptide dissolves poorly in non-polar solvents such as hexane or chloroform. Stock solutions are often prepared in water first and then diluted into the buffer of interest. Because the molecule is small and hydrophilic, filtration through a low-protein-binding membrane is usually straightforward, and visible particulates are uncommon in freshly made solutions.
== Bibliography == Alt-Kutscha : vol.1 Archived 2020-01-27 at the Wayback Machine Arlt, Robert; Hiyama, Satomi (2013). "Fruits of Research on the History of Central Asian Art in Berlin: The Identification of Two Sermon Scenes from Kizil Cave 206 (Fußwaschungs- höhle)". Indo-Asiatische Zeitschrift (Berlin) 17: 16–26. Beckwith, Christopher (1993). The Tibetan Empire in Central Asia: A History of the Struggle for Great Power Among Tibetans, Turks, Arabs, and Chinese During the Early Middle Ages. Princeton University Press. ISBN 0-691-02469-3. Beckwith, Christopher I. (2009). Empires of the Silk Road: A History of Central Eurasia from the Bronze Age to the Present. Princeton University Press. ISBN 978-0-691-13589-2. Grousset, René (1970). The Empire of the Steppes: A History of Central Asia. Rutgers University Press. ISBN 978-0-8135-1304-1. Grünwedel, Albert (1912). Altbuddhistische Kultstätten in Chinesisch-Turkistan: Bericht über archäologische Arbeiten von 1906 bis 1907 bei Kuča, Qarašahr und in der Oase Turfan. Berlin: Arthur-Baessler-Institut. Doi:10.20676/00000191. Hopkirk, Peter (1984). Foreign devils on the silk road : the search for the lost cities and treasures of Chinese Central Asia. Amherst: University of Massachusetts Press. ISBN 9780870234354. Hiyama, Satomi 檜山智美 (2013) Study on the first-style murals of Kucha: Analysis of some motifs related to the Hephthalite's period クチャの第一樣式壁畫に見られるエフタル期のモチーフについて (“Kucha no daiichi yōshiki hekiga ni mirareru Efutaru ki no mochīfu ni tsuite”).
Several obstacles have been encountered in the development of astatine-based radiopharmaceuticals for cancer treatment. World War II delayed research for close to a decade. Results of early experiments indicated that a cancer-selective carrier would need to be developed and it was not until the 1970s that monoclonal antibodies became available for this purpose. Unlike iodine, astatine shows a tendency to dehalogenate from molecular carriers such as these, particularly at sp3 carbon sites (less so from sp2 sites). Given the toxicity of astatine accumulated and retained in the body, this emphasized the need to ensure it remained attached to its host molecule. While astatine carriers that are slowly metabolized can be assessed for their efficacy, more rapidly metabolized carriers remain a significant obstacle to the evaluation of astatine in nuclear medicine. Mitigating the effects of astatine-induced radiolysis of labeling chemistry and carrier molecules is another area requiring further development. A practical application for astatine as a cancer treatment would potentially be suitable for a "staggering" number of patients; production of astatine in the quantities that would be required remains an issue. Animal studies show that astatine, similarly to iodine—although to a lesser extent, perhaps because of its slightly more metallic nature—is preferentially (and dangerously) concentrated in the thyroid gland. Unlike iodine, astatine also shows a tendency to be taken up by the lungs and spleen, possibly because of in-body oxidation of At− to At+.
=== Music === V.I.P. (Hungarian band), a defunct pop boy group The V.I.P.'s (band), an English band of the 1960s Voices in Public, a Canadian boy group VVIP (hip-hop group), a Ghanaian hiplife band, formerly known as VIP (or Vision In Progress) V.I.P. (album), a 2000 album by Jungle Brothers, or the title track "V.I.P." (Bro'Sis song) (2003) "V.I.P" (Ice Prince song) (2013) "V.I.P" (Sid song) (2013) "VIP" (Aya Nakamura song) (2022) V.I.P., a subsidiary label of Motown Records VIP Music Records, an American record label based in New York City (founded 2004) VIP Records, a record store chain from Los Angeles, California (founded 1967) "VIP", a song by Kesha from Animal (Kesha album) The V.I.P. (The Vanilla Ice Posse), the rapper's DJs and backup dancers Victory in Praise Music and Arts Seminar Mass Choir, an organization founded by John P. Kee "V.I.P.", a song by Françoise Hardy "V.I.P.", a song by R. Kelly from R. (R. Kelly album) V.V.I.P, a 2011 EP by Seungri V.I.P. – Very Important Pony, 2025 EP by HorsegiirL
Sources: en.wikipedia.org
== Single-cell protein and gasohol projects == Even greater expectations of biotechnology were raised during the 1960s by a process that grew single-cell protein. When the so-called protein gap threatened world hunger, producing food locally by growing it from waste seemed to offer a solution. It was the possibilities of growing microorganisms on oil that captured the imagination of scientists, policy makers, and commerce. Major companies such as BP staked their futures on it. In 1962, BP built a pilot plant at Cap de Lavera in Southern France to publicize its product, Toprina. Initial research work at Lavera was done by Alfred Champagnat, In 1963, construction started on BP's second pilot plant at the Grangemouth Refinery in Scotland. As there was no well-accepted term to describe the new foods, in 1966 the term "single-cell protein" (SCP) was coined at MIT to provide an acceptable and exciting new title, avoiding the unpleasant connotations of microbial or bacterial. The "food from oil" idea became quite popular by the 1970s, when facilities for growing yeast fed by n-paraffins were built in a number of countries. The Soviets were particularly enthusiastic, opening large "BVK" (belkovo-vitaminny kontsentrat, i.e., "protein-vitamin concentrate") plants next to their oil refineries in Kstovo (1973) and Kirishi (1974). By the late 1970s, however, the cultural climate had completely changed, as the growth in SCP interest had taken place against a shifting economic and cultural scene (136).
Sub-slab depressurization (soil suction) by increasing under-floor ventilation; Improving the ventilation of the house and avoiding the transport of radon from the basement into living rooms; Installing a radon sump system in the basement; Installing a positive pressurization or positive supply ventilation system. According to the EPA, the method to reduce radon "...primarily used is a vent pipe system and fan, which pulls radon from beneath the house and vents it to the outside", which is also called sub-slab depressurization, active soil depressurization, or soil suction. Generally indoor radon can be mitigated by sub-slab depressurization and exhausting such radon-laden air to the outdoors, away from windows and other building openings. "[The] EPA generally recommends methods which prevent the entry of radon. Soil suction, for example, prevents radon from entering your home by drawing the radon from below the home and venting it through a pipe, or pipes, to the air above the home where it is quickly diluted" and the "EPA does not recommend the use of sealing alone to reduce radon because, by itself, sealing has not been shown to lower radon levels significantly or consistently". Positive-pressure ventilation systems can be combined with a heat exchanger to recover energy in the process of exchanging air with the outside, and simply exhausting basement air to the outside is not necessarily a viable solution as this can actually draw radon gas into a dwelling.
=== Biochemical === In size-exclusion chromatography, the residence time of a molecule is related to its volume, which is roughly proportional to its molecular weight. Residence times also affect the performance of continuous fermentors. Biofuel cells utilize the metabolic processes of anodophiles (electronegative bacteria) to convert chemical energy from organic matter into electricity. A biofuel cell mechanism consists of an anode and a cathode that are separated by an internal proton exchange membrane (PEM) and connected in an external circuit with an external load. Anodophiles grow on the anode and consume biodegradable organic molecules to produce electrons, protons, and carbon dioxide gas, and as the electrons travel through the circuit they feed the external load. The HRT for this application is the rate at which the feed molecules are passed through the anodic chamber. This can be quantified by dividing the volume of the anodic chamber by the rate at which the feed solution is passed into the chamber. The hydraulic residence time (HRT) affects the substrate loading rate of the microorganisms that the anodophiles consume, which affects the electrical output. Longer HRTs reduce substrate loading in the anodic chamber, which can lead to a reduced anodophile population and performance when there is a deficiency of nutrients.
Gerry Gable (born 27 January 1937); political activist; was editor of Searchlight magazine; was member of Communist Party of Great Britain; worked as runner on Communist Party's Daily Worker newspaper; left the Communist Party because of their anti-Israel policy and because "first and foremost [he has] always been a Jewish trade unionist"; was commissioned by BBC to produce research for a BBC Panorama programme "Maggie's Militant Tendency"; was convicted in January 1964 of burglary of historian David Irving's flat Martha Gellhorn (8 November 1908 – 15 February 1998) American novelist, travel writer, and journalist who settled, retired and died in England; considered one of the great war correspondents of the 20th century. Andrew Gold (journalist) (b.1989); British Jewish journalist, YouTuber, filmmaker, author, podcaster;in 2023, Gold launched his YouTube podcast, Heretics; has written for UnHerd, Vice, Jewish News, HuffPost , Times of Israel and the BBC. Tanya Gold (born 31 December 1973) is an English journalist who has written for The Jewish Chronicle, The New York Times The Guardian, the Daily Mail, The Independent, The Daily Telegraph, The Sunday Times and the Evening Standard, and for The Spectator magazine. Vivien Goldman is a British punk rock and reggae journalist and historian, writer and musician of German Jewish ancestry.
Sources: en.wikipedia.org
== NPHCDA tenure == Muhammad worked to achieve seven major objectives at the NPHCDA. The objectives were: To control preventable diseases; Improve access to basic health services; Improve quality of care; Strengthen institutions in the healthcare system; Develop a high-performing and empowered health workforce across the country. Other goals are to strengthen partnerships and engage with communities regularly to get feedback.
Dams – the Aztec in Tenochtitlan constructed great dams during the heyday of the Aztec Empire. Tenochtitlan, the capital of the Aztec empire, was first built on a small island that was located in the western section of Lake Texcoco in 1325 CE. The Aztec created various large artificial islands around the small island using a system that was similar to building the chinampas (floating gardens in the lake that was used to grow food for the cities' population). To provide drinking water to the cities' population of over a quarter of a million inhabitants, the Aztec built a system of dams that separated the salty waters of the lake from the rainwater that was accumulated during periods of heavy rains. The Aztec also used the dam to control the level of water in the lake and prevent their city from being flooded during times of heavy rains. To prevent flooding, the Aztec constructed an inner system of channels that helped to control the water level and held the level steady during flooding and periods of intense rains. Hernán Cortés, and the other Spanish conquistadors, destroyed these engineering marvels that the Aztec had developed during the previous 200 years. Dog breeds – Native American dogs believed to have been bred by indigenous Americans are the xochiocoyotl (coyote), xoloitzcuintli (known as xolo or Mexican hairless), chihuahua, Peruvian Hairless Dog, the Carolina Dog, Canadian Eskimo Dog, and the Alaskan Malamute.
=== Immune system === Besides the metabolic function, insulin receptors are also expressed on immune cells, such as macrophages, B cells, and T cells. On T cells, the expression of insulin receptors is undetectable during the resting state but up-regulated upon T-cell receptor (TCR) activation. Indeed, insulin has been shown when supplied exogenously to promote in vitro T cell proliferation in animal models. Insulin receptor signalling is important for maximizing the potential effect of T cells during acute infection and inflammation.
A testicular action was linked to circulating blood fractions – now understood to be a family of androgenic hormones – in the early work on castration and testicular transplantation in fowl by Arnold Adolph Berthold (1803–1861). Research on the action of testosterone received a brief boost in 1889, when the Harvard professor Charles-Édouard Brown-Séquard (1817–1894), then in Paris, self-injected subcutaneously a "rejuvenating elixir" consisting of an extract of dog and guinea pig testicle. He reported in The Lancet that his vigor and feeling of well-being were markedly restored but the effects were transient, and Brown-Séquard's hopes for the compound were dashed. Suffering the ridicule of his colleagues, he abandoned his work on the mechanisms and effects of androgens in human beings. In 1927, the University of Chicago's Professor of Physiologic Chemistry, Fred C. Koch, established easy access to a large source of bovine testicles – the Chicago stockyards – and recruited students willing to endure the tedious work of extracting their isolates. In that year, Koch and his student, Lemuel McGee, derived 20 mg of a substance from a supply of 40 pounds of bovine testicles that, when administered to castrated roosters, pigs and rats, re-masculinized them.
=== Evidence === The reaction mechanism of Trypanosoma brucei's ODC with ornithine was characterized by UV-VIS spectroscopy in order to identify unique intermediates that occurred during the reaction. The specific method of multiwavelength stopped-flow spectroscopy utilized monochromatic light and fluorescence to identify five specific intermediates due to changes in absorbance measurements. The steady-state turnover number, kcat, of ODC was calculated to be 0.5 s−1 at 4 °C. From this characterization, the rate-limiting step was determined to be the release of the product putrescine from ODC's reaction with ornithine. In studying the hypothetical reaction mechanism for eflornithine, information collected from radioactive peptide and eflornithine mapping, high pressure liquid chromatography, and gas phase peptide sequencing suggested that Lys-69 and Cys-360 are covalently bound to eflornithine in T. brucei ODC's active site. Utilizing fast-atom bombardment mass spectrometry (FAB-MS), the structural conformation of eflornithine following its interaction with ODC was determined to be (S)-((2-(1-pyrroline-methyl) cysteine, a cyclic imine adduct. Presence of this particular product was supported by the possibility to further reduce the end product to (S)-((2-pyrrole) methyl) cysteine in the presence of NaBH4 and oxidize the end product to (S)-((2-pyrrolidine) methyl) cysteine (Figure 2).
Sources: en.wikipedia.org
Mass spectrometry provides the identity check, because the observed mass is compared with the theoretical mass of the AEDG sequence. Chromatography separates and quantifies impurities but does not by itself prove which peptide is present. The two techniques are normally used together.
Yes. Trifluoroacetate and acetate ions remain associated with the peptide after purification, so a weighed quantity of powder contains less peptide than the nominal mass suggests. Certificates that report net peptide content rather than raw weight are more directly comparable between suppliers.
Dilute aqueous solutions are less stable than the dry powder and are usually aliquoted and frozen to avoid repeated freeze–thaw cycles. Lyophilised material is best stored desiccated at −20 °C, protected from light. Working solutions are typically prepared fresh from a frozen aliquot.
Small studies with human participants have been reported, chiefly in Russian-language journals, but they are limited in size and design. No large randomised controlled trial with published results is available.