Everything below concerns ICP-MS. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-07-17. Numbers and descriptions here follow the published literature rather than marketing material.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, frequently paired with mass spectrometry to confirm the molecular ion. Copper content is measured separately, typically by inductively coupled plasma mass spectrometry or atomic absorption spectroscopy, because the chromatographic signal reports the peptide rather than the metal. Ultraviolet-visible spectroscopy provides a fast check on complex formation, since copper(II) peptide complexes absorb in the visible region. Elemental analysis and amino acid analysis are used less often but remain useful for reference standards. A gap between reported peptide purity and measured copper content is a recurring source of confusion.
Material described as GHK-Cu appears in several distinct markets, including cosmetic ingredients, laboratory reagents, and consumer products, and the quality expectations attached to each differ. A certificate of analysis generally reports peptide purity by chromatography, copper content, appearance, and residual solvents or counterions. Counterion identity matters, because the complex is usually supplied as an acetate or a similar salt, and the counterion contributes to the measured mass. Independent verification of sequence and metal stoichiometry is advisable when a material is used for quantitative work. Batch-to-batch variation is common and should be documented rather than assumed negligible.
Analytical verification commonly relies on high-performance liquid chromatography for purity assessment and mass spectrometry for identity confirmation. Spectroscopic methods such as UV-visible absorption and electron paramagnetic resonance can probe the metal centre itself, since the d9 configuration of copper(II) produces characteristic signals. Elemental analysis or plasma-based techniques quantify copper content. Because each method reports a different aspect of the same sample, purity figures are most meaningful when the technique and its detection wavelength are stated alongside the value.
Stability of the complex in solution depends on pH, temperature, and the presence of competing ligands. It is generally described as more resistant to breakdown than the metal-free chain, since coordination reduces susceptibility to enzymatic attack. Oxidation and hydrolysis can nevertheless proceed over time in aqueous media. Storage guidance in laboratory settings commonly involves refrigeration, protection from light, and avoidance of strongly alkaline conditions. Published data on long-term behaviour vary considerably and depend on the specific matrix.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C for solid; 2-8 °C for short-term solution use | Avoid repeated freeze-thaw cycles |
| Preferred solvent | Water or aqueous buffer near neutral pH | Nonpolar solvents give poor dissolution |
| Typical analytical method | Reversed-phase HPLC with mass spectrometry | Copper quantified separately by ICP-MS |
| Principal degradation routes | Backbone hydrolysis, histidine oxidation, photolysis | Alkaline pH accelerates hydrolysis |
| Counterion form | Acetate salt is common | Counterion contributes to measured mass |
Purity assessment typically involves high-performance liquid chromatography for the peptide and atomic spectroscopy for copper content. The ratio of copper to peptide is a key quality parameter; a value near one indicates proper stoichiometry. Impurities can include free peptide, copper salts, and truncated sequences from synthesis. Because the complex is dynamic, sample preparation and mobile-phase conditions can shift the observed species. Reported purity values therefore depend on the analytical method and should be interpreted with that context.
Characterizing GHK-Cu requires methods that distinguish the intact complex from free peptide and unbound copper. UV-visible absorption around 600 nm provides a rapid check for copper coordination, while circular dichroism reports on peptide secondary structure. Mass spectrometry confirms the peptide mass and can detect copper adducts under carefully controlled conditions. Electron paramagnetic resonance is particularly informative for Cu(II) because it reveals the ligand field symmetry. No single technique fully defines the complex, so laboratories combine orthogonal methods.
Published work on GHK-Cu concentrates largely on cell culture systems rather than whole organisms. Frequently used endpoints include collagen synthesis, expression of matrix metalloproteinases, and migration of fibroblasts. Some reports describe antioxidant behavior, while others stress delivery of copper into cells. These mechanisms are proposed rather than demonstrated, and the relative weight of each pathway is unclear. Human trials are few and generally small, so laboratory findings should not be read as confirmed clinical results.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide backbone consists of glycine, histidine, and lysine joined in that order. Copper is held through the imidazole nitrogen of histidine and the alpha-amino group at the N-terminus, which together produce a square-planar arrangement around the metal center. The solid appears blue to violet, a color that originates from d-d electronic transitions within the copper coordination sphere. The complex is indexed under CAS number 89030-95-5.
The sequence now called GHK was first reported in the early 1970s after isolation from human plasma, where it was noted to influence liver cell behavior in laboratory preparations. Later work described a copper-binding form and its activity in fibroblast and wound-model experiments. Review articles frequently group the substance with other copper peptides. Concentrations in blood appear to fall with age in several small surveys, although the reason for this trend is not settled. Whether such a decline carries functional consequences remains an open question.
The peptide sequence places a histidine in the middle, and this residue dominates metal binding. Copper(II) coordinates through the imidazole nitrogen of histidine and the terminal amino group, forming a stable chelate ring system. Loss of the copper ion leaves the free tripeptide, which has different solubility and reactivity. This structural detail matters because assays that measure only the peptide backbone can miss whether copper is still bound to it.
Several names circulate for the same material, which complicates literature searches. Cosmetic ingredient lists often use copper tripeptide-1, while older biochemistry papers use glycyl-L-histidyl-lysine or its abbreviation GHK. The copper complex is sometimes written as GHK-Cu(II) to make the oxidation state explicit. Terminology is not fully standardized, so matching a compound across sources requires attention to the exact sequence, the counterion, and the stated copper content. Reviews that compare studies must account for these naming differences before drawing conclusions.
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine, a short sequence of three amino acids. The peptide was first isolated from human plasma in 1973 during research on factors that influence tissue repair in liver. Its ability to bind copper ions became a central point of interest because the metal changes the peptide's chemistry and its behaviour in laboratory systems. Today the compound appears in cosmetic formulations, cell-culture studies, and biochemistry literature under several names.
==== Regulations ==== Hitchens was known for his dislike of Nanny state policies put in place by New York city mayor Michael Bloomberg. On 9 July 2009, Hitchens wrote an article criticizing and mocking New York city regulations including smoking laws, bicycle laws, milk crate laws and other regulations. In the same article Hitchens claimed he had broken the laws he had criticized in the article.
=== Overdose issues === In 2007, a nurse at Cedars-Sinai Medical Center mistakenly gave the 12-day-old twins of actor Dennis Quaid a dose of heparin that was 1,000 times the recommended dose for infants. The overdose allegedly arose because the labeling and design of the adult and infant versions of the product were similar. The Quaid family subsequently sued the manufacturer, Baxter Healthcare Corp., and settled with the hospital for $750,000. Prior to the Quaid accident, six newborn babies at Methodist Hospital in Indianapolis, Indiana, were given an overdose. Three of the babies died after the mistake. In July 2008, another set of twins born at Christus Spohn Hospital South, in Corpus Christi, Texas, died after an accidentally administered overdose of the drug. The overdose was due to a mixing error at the hospital pharmacy and was unrelated to the product's packaging or labeling. As of July 2008, the exact cause of the twins' death was under investigation. In March 2010, a two-year-old transplant patient from Texas was given a lethal dose of heparin at the University of Nebraska Medical Center. The exact circumstances surrounding her death are still under investigation.
== External links == Basel, Yochai; Hassner, Alfred (2001). "Imidazole and Trifluoroethanol as Efficient and Mild Reagents for Destruction of Excess Di-tert-butyl Dicarbonate [(BOC)2O]". Synthesis. 2001 (4): 0550. doi:10.1055/s-2001-12350. S2CID 97029361.
Artificial cartilage is a synthetic material made of hydrogels or polymers that aims to mimic the functional properties of natural cartilage in the human body. Tissue engineering principles are used in order to create a non-degradable and biocompatible material that can replace cartilage. While creating a useful synthetic cartilage material, certain challenges need to be overcome. First, cartilage is an avascular structure in the body and therefore does not repair itself. This creates issues in regeneration of the tissue. Synthetic cartilage also needs to be stably attached to its underlying surface i.e. the bone. Lastly, in the case of creating synthetic cartilage to be used in joint spaces, high mechanical strength under compression needs to be an intrinsic property of the material.
== Biochemistry == Pyruvate is important in biochemistry. It is the output of the metabolism of glucose known as glycolysis. One molecule of glucose breaks down into two molecules of pyruvate, which are then used to provide further energy, in one of two ways. Pyruvate is converted into acetyl-coenzyme A, which is the main input for a series of reactions known as the Krebs cycle (also known as the citric acid cycle or tricarboxylic acid cycle). Pyruvate is also converted to oxaloacetate by an anaplerotic reaction, which replenishes Krebs cycle intermediates; also, the oxaloacetate is used for gluconeogenesis. These reactions are named after Hans Adolf Krebs, the biochemist awarded the 1953 Nobel Prize for physiology, jointly with Fritz Lipmann, for research into metabolic processes. The cycle is also known as the citric acid cycle or tricarboxylic acid cycle, because citric acid is one of the intermediate compounds formed during the reactions. If insufficient oxygen is available, the acid is broken down anaerobically, creating lactate in animals and ethanol in plants and microorganisms (and in carp). Pyruvate from glycolysis is converted by fermentation to lactate using the enzyme lactate dehydrogenase and the coenzyme NADH in lactate fermentation, or to acetaldehyde (with the enzyme pyruvate decarboxylase) and then to ethanol in alcoholic fermentation. Pyruvate is a key intersection in the network of metabolic pathways. Pyruvate can be converted into carbohydrates via gluconeogenesis, to fatty acids or energy through acetyl-CoA, to the amino acid alanine, and to ethanol.
Sources: en.wikipedia.org
== Reception == The review-aggregator website Rotten Tomatoes reported a 100% approval rating based on 36 critic reviews. According to the website's critics' consensus: "Tackling emotionally mature themes with an ingeniously zany sense of humor, Raphael Bob-Waksberg's Long Story Short welcomes viewers into a highly specific—and extremely relatable—family unit". Metacritic, which uses a weighted average, gave a score of 89 out of 100 based on 17 critics, indicating "universal acclaim". Jenna Scherer of The A.V. Club gave the show's first season a rating of A− and wrote: "The series is all about how people change over the years—and the fact that, no matter how far you run, the past always returns to haunt the present". Reviewing the series' first season for The Guardian, Stuart Heritage gave a rating of 4/5, saying it "reminds us that everything is an echo of what came before. This is a testament to Bob-Waksberg's writing. This level of granular, non-linear character development must have been a feat to construct, and yet it feels effortless."
== External links == Official website of Lotte Bjerre Knudsen An unofficial source listing the publications of Knudsen. A formal source of patents issued to Knudsen. The 2022 Danish TV mini-series, "The Story of GLP-1", focused on the work of Knudsen.
=== Enhanced excretion === In some situations elimination of the poison can be enhanced using diuresis, hemodialysis, hemoperfusion, hyperbaric medicine, peritoneal dialysis, exchange transfusion or chelation. However, this may actually worsen the poisoning in some cases, so it should always be verified based on what substances are involved.
The price of real estate in Moscow continues to increase. The expected price averages $4,000 per square meter (11 sq ft) near the perimeter of the city or $6,500–8,000 per square meter in a prestigious district. The price sometimes exceeds $40,000 per square meter for a flat. Renting costs about $1,200 per month for a one-bedroom apartment and about $1,000 per month for a studio in the city center. A typical one-bedroom apartment in Moscow is about 30 square meters (320 square feet) in area; a typical two-bedroom apartment is 45 square meters (480 square feet); and a typical three-bedroom apartment is 70 square meters (750 square feet). Many residents cannot move out of their apartments, especially if a family lives in a two-room apartment originally granted by the state during the Soviet era. Some city residents have attempted to cope with the cost of living by renting out their apartments while staying in dachas (country houses) outside the city. In 2006, Mercer Human Resources Consulting named Moscow the world's most expensive city for expatriate employees, ahead of recurring winner Tokyo, because of the stable Russian ruble as well as increasing housing prices. Moscow also ranked first in the 2007 edition and 2008 edition of the survey. However, in 2009, Tokyo overtook Moscow, which came in third after Osaka. In 2014, according to Forbes magazine, Moscow was ranked the world's ninth most expensive city. This magazine ranked Moscow the second most expensive city the previous year.
An analysis of GPX1 expression in oligodendrocytes from patients with major depressive disorder and control patients showed that GPX1 levels were significantly decreased in patients with the disorder, but not in their astrocytes. Shortening of telomeres and decreased expression of telomerase were also evident in these oligodendrocytes, but not in the astrocytes in these patients. This suggests that decreased oxidative stress protection, as observed by decreased GPX1 levels, and decreased telomerase expression may help give rise to telomere shortening in patients with MDD.
Sources: en.wikipedia.org
== Research == Preliminary research suggests that topical finasteride may be effective in the treatment of pattern hair loss. Topical finasteride, like the oral preparation, reduces serum DHT. DHT may be involved in the cause of acne, and 5α-reductase inhibitors might be effective in the treatment of the condition. A small retrospective study reported that finasteride was effective in the treatment of acne in women with normal testosterone levels. A randomized controlled trial found that finasteride was less effective than flutamide or an ethinylestradiol/cyproterone acetate birth control pill in the treatment of acne in women with high androgen levels. Androgens and estrogens may be involved in the cause of hidradenitis suppurativa (acne inversa). Two case series have reported that finasteride is effective in the treatment of hidradenitis suppurativa in girls and women. Finasteride and other antiandrogens might be useful in the treatment of obsessive–compulsive disorder (OCD), but more research is needed.
Chain Home, or CH for short, was the codename for the ring of coastal early warning radar stations built by the Royal Air Force (RAF) before and during the Second World War to detect and track aircraft. Initially known as RDF, and given the official name Air Ministry Experimental Station Type 1 (AMES Type 1) in 1940, the radar units were also known as Chain Home for most of their life. Chain Home was the first early warning radar network in the world and the first military radar system to reach operational status. Its effect on the war made it one of the most powerful systems of what became known as the "Wizard War". In late 1934, the Tizard Committee asked radio expert Robert Watson-Watt to comment on the repeated claims of radio death rays and reports suggesting Germany had built some sort of radio weapon. His assistant, Arnold Wilkins, demonstrated that a death ray was impossible but suggested radio could be used for long-range detection. In February 1935, a successful demonstration was arranged by placing a receiver near a BBC short wave transmitter and flying an aircraft around the area. Using commercial short wave radio hardware, Watt's team built a prototype pulsed transmitter and, by June 1935, it detected an aircraft that happened to be flying past. Basic development was completed by the end of the year, with detection ranges on the order of 100 mi (160 km). In 1936, attention was focused on a production version, and early 1937 saw the addition of height finding.
The problem is, of course, that they can't afford to fail. The rules of the game are that you don't take a chance, because if you fail, then probably your whole program gets wiped out. Dyson still hoped for cheap space travel, but was resigned to waiting for private entrepreneurs to develop something new and inexpensive.
== Scientific achievements == In 1940, Li successfully purified the luteinizing hormone from sheep pituitary glands. The whole process included grinding thousands of glands, extracting the hormone, and then identifying its chemistry and biology at the molecular level. This was a breakthrough in biological studies. Eight of the nine hormones secreted by the anterior pituitary were isolated and identified by Li and his research team. These nine hormones can be divided into three groups based on the similarity of their chemical properties and biological activities. The first group includes adrenocorticotropic hormone (ACTH), melanocyte-stimulating hormones (MSH), and lipotropin.
From the analysis of individual atoms within proteins to the genetic and protein-based reconstruction of complex biological systems, the department provides various vital links between basic and translational biomedical research, contributing heavily to the C700 Biochemistry and C130 Biomedical Sciences undergraduate degree programmes and MSc taught courses in Bioinformatics and Biotechnology.
Sources: en.wikipedia.org
The solid is typically held cold and dry, and solutions are kept for shorter periods because hydrolysis proceeds in water. Repeated freeze-thaw cycles are usually avoided, since they can degrade both the peptide and the complex. Container material and headspace also affect how long a sample remains unchanged.
Copper is quantified by an elemental technique such as inductively coupled plasma mass spectrometry, not by peptide chromatography. The chromatographic result describes the peptide chain, while the elemental result describes the metal. Reporting both is what makes the stoichiometry checkable.
It normally lists the analytical methods used, the measured purity, the appearance, and any residuals or counterions detected. It is a statement about a specific batch rather than a general property of the material. Independent testing is still needed when results must be traceable to a reference standard.
Reverse-phase high-performance liquid chromatography with ultraviolet detection is the most common approach. Purity is expressed as a share of total peak area at a specified wavelength. Mass spectrometry is then used to confirm molecular identity.