Electrospray ionization 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 2026-05-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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 | Lyophilized solid from research suppliers |
| Solubility | Freely soluble in water | Also dissolves in aqueous buffers; solutions are used fresh |
| Typical storage temperature | -20 °C for lyophilized powder | Short-term transport at 2-8 °C is common |
| Common analytical method | Reverse-phase HPLC | Paired with mass spectrometry for identity confirmation |
| Common synonyms | ACTH(4-10) analogue; MEHFPGP | N-terminal methionine retained in the chain |
3 cos Ω = 1 − 4 cos2 φ + ψ/2 The α-helix is tightly packed; there is almost no free space within the helix. The amino-acid side-chains are on the outside of the helix, and point roughly "downward" (i.e., toward the N-terminus), like the branches of an evergreen tree (Christmas tree effect). This directionality is sometimes used in preliminary, low-resolution electron-density maps to determine the direction of the protein backbone.
== Sources == Topographic maps and Geologic Folios of the United States Geological Survey Goodge, J. W.; Vervoort, J. D.; Fanning, C. M.; Brecke, D. M.; Farmer, G. L.; Williams, I. S.; Myrow, P. M.; DePaolo, D. J. (2008). "A positive test of East Antarctica–Laurentia juxtaposition within the Rodinia supercontinent" (PDF). Science. 321 (5886): 235–240. Bibcode:2008Sci...321..235G. doi:10.1126/science.1159189. ISSN 0036-8075. PMID 18621666. S2CID 11799613. Retrieved February 4, 2016. Loewy, S. L.; Dalziel, I. W. D.; Pisarevsky, S.; Connelly, J. N.; Tait, J.; Hanson, R. E.; Bullen, D. (2011). "Coats Land crustal block, East Antarctica: A tectonic tracer for Laurentia?". Geology. 39 (9): 859–862. Bibcode:2011Geo....39..859L. doi:10.1130/G32029.1. Retrieved January 24, 2016.
==== Ultrasonic couplant ==== Glycerol can be sometimes used as replacement for water in ultrasonic testing, as it has favourably higher acoustic impedance (2.42 MRayl versus 1.483 MRayl for water) while being relatively safe, non-toxic, non-corrosive and relatively low cost.
Sources: en.wikipedia.org
=== Heart === In 2013, a study found major vascular events were increased by about a third by diclofenac, chiefly due to an increase in major coronary events. Compared with placebo, of 1000 people allocated to diclofenac for a year, three more had major vascular events, one of which was fatal. Vascular death was increased by diclofenac (1·65). Following the identification of increased risks of heart attacks with the selective COX-2 inhibitor rofecoxib in 2004, attention has focused on all the other members of the nonsteroidal anti-inflammatory drug group, including diclofenac. Research results are mixed, with a meta-analysis of papers and reports up to April 2006 suggesting a relative increased rate of heart disease of 1.63 compared to nonusers. Professor Peter Weissberg, medical director of the British Heart Foundation said, "However, the increased risk is small, and many patients with chronic debilitating pain may well feel that this small risk is worth taking to relieve their symptoms". Only aspirin was found not to increase the risk of heart disease; however, this is known to have a higher rate of gastric ulceration than diclofenac. As of January 2015, the MHRA announced that diclofenac would be reclassified as a prescription-only medicine (POM) due to the risk of cardiovascular adverse events. A 2006 large observational study of 74,838 US users of nonsteroidal anti-inflammatory drugs or coxibs found no additional cardiovascular risk from diclofenac use.
4-nitrocatechol 4-monooxygenase (EC 1.14.13.166) is an enzyme with systematic name 4-nitrocatechol,NAD(P)H:oxygen 4-oxidoreductase (4-hydroxylating, nitrite-forming).This enzyme catalyses the following chemical reaction:
== Death == Angelopoulos died late on Tuesday, 24 January 2012, several hours after being involved in a crash while shooting his latest film, The Other Sea in Athens. On that evening, the filmmaker had been with his crew in the area of Drapetsona, near Piraeus when he was hit by a motorcycle, which unconfirmed reports suggested was ridden by an off-duty police officer. The crash occurred when Angelopoulos, 76, attempted to cross a busy road. He was taken to a hospital, where he was treated in an intensive care unit but succumbed to his serious injuries several hours later. His funeral was a public expense, on 27 January at the First Cemetery of Athens.
==== Operation and distribution ==== All of Chipotle's restaurants are company-owned, rather than franchised. As of December 2012, 1,430 restaurants have since opened throughout the United States and Canada, with locations in 43 states, Ontario, British Columbia, and the District of Columbia. The field team are the employees who work closely with, but not directly within, specific restaurants. The field support system includes apprentice team leaders (step up from restaurateurs), team leaders or area managers, team directors, and regional directors (not atypical for them to oversee more than fifty locations). Because Chipotle does not franchise, all restaurants are owned and operated directly by the corporation itself. Thus, whenever Chipotle is in the process of launching a new location, the field team hires a new general manager and trains them at a current location so that they will be ready for the new location when it opens for business. The corporate office takes care of finding and funding new locations as well. In July 2023, the company announced it was testing a robot developed to cut the time to prepare avocados for guacamole in half amid an ongoing labor shortage. It was one of multiple chains incorporating automation into its operations at the time. It shows that the way food information is presented can significantly affect what people decide to eat, often shaping perceptions of healthfulness and encouraging certain purchasing behaviors.
Sources: en.wikipedia.org
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.
A fraction of an intranasal dose is thought to reach the central nervous system, and this route is favoured partly for that reason. The proportion is not well characterized. Direct measurement in humans remains difficult with current methods.
Raised BDNF and NGF expression has been reported across several animal studies, which makes the signal fairly consistent. Whether the same change occurs in humans at usable doses is not established. It is best treated as a working hypothesis rather than a confirmed clinical mechanism.
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.