A practical reference on reversed-phase HPLC: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-05 and is reviewed periodically as new material appears.
The dividing feature between the two forms is a maleimide-based drug affinity complex, abbreviated DAC. In the DAC-bearing version, a linker attaches the peptide to serum albumin after administration, and that association slows removal from plasma. The version lacking DAC appears in catalogs as MOD GRF(1-29) or tetrasubstituted GRF(1-29). Because informal writing treats both as one item, comparisons drawn from such sources routinely blend measurements taken from two molecules with substantially different behavior.
Four amino acid substitutions separate the modified backbone from the parent GRF(1-29) sequence. These changes reduce recognition by dipeptidyl peptidase IV and related proteases, extending the interval before degradation. Development work in this area sought longer-acting GHRH analogs for endocrine investigation. Published descriptions treat the substitution set as a defining property of the core sequence, while the albumin-binding linker is described separately as an optional addition to that same backbone.
Two forms circulate in research settings and are frequently confused. One carries the drug affinity complex and is often written as CJC-1295 with DAC; the other lacks that group and is usually called modified GRF(1-29). The two share the same core sequence but differ sharply in how long they persist in blood. Products labelled only as CJC-1295 normally refer to the version carrying the complex. Documentation that omits the distinction leaves the intended molecule ambiguous.
CJC-1295 is a synthetic peptide built as a long-acting analogue of growth hormone-releasing hormone. Its backbone matches the first twenty-nine residues of the natural human hormone, with four amino acid substitutions added to slow enzymatic breakdown. A reactive maleimide group, commonly termed the drug affinity complex, allows the peptide to attach to circulating albumin after administration. That albumin attachment keeps the molecule in the bloodstream for an extended period instead of being cleared within minutes.
The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Analog of growth hormone-releasing hormone |
| Chain length | 29 amino acids | Based on the GRF(1-29) fragment |
| Appearance | White to off-white lyophilized powder | Common research supply form |
| Solubility | Soluble in water and aqueous buffers | Powder requires reconstitution before use |
| Typical storage | −20 °C or below | Kept away from light and moisture |
Verification matters because research peptides vary widely in quality. A certificate of analysis is only as reliable as the method behind it, and a single chromatographic trace reveals little about counter-ions, residual solvents, or water content. Independent laboratories commonly pair mass confirmation with chromatographic purity and, where relevant, quantify water along with acetate or trifluoroacetate content. Reported purity figures are not standardized across suppliers, so a stated value such as ninety-eight percent is not directly comparable unless the analytical method, column, and detection wavelength accompany it.
Characterization of this peptide relies on a small set of routine techniques. Reversed-phase high-performance liquid chromatography separates the target from truncated or oxidized by-products and yields a purity estimate when paired with ultraviolet detection near 214 nanometers. Mass spectrometry, either electrospray coupled to liquid chromatography or matrix-assisted laser desorption, confirms that the observed mass matches the value calculated for the expected sequence. Amino acid analysis, and enzymatic digestion followed by fragment mapping, are used when the sequence itself rather than the mass requires verification.
Two related peptides circulate under the CJC-1295 label, and they differ mainly in how long they persist in circulation. The version carrying a drug affinity complex includes a maleimidopropionic acid linker that forms a covalent bond with serum albumin. The other version, usually written as modified GRF(1-29) or tetrasubstituted GRF(1-29), lacks that linker and is cleared quickly. Mixing the two produces inconsistent readings of published half-life values, because the linker rather than the receptor-facing sequence drives most of the difference.
The core sequence keeps the receptor-binding region of GHRH while replacing four positions that are vulnerable to dipeptidyl peptidase-4 and other proteases. Substitutions at positions 2, 8, 15, and 27 raise metabolic stability relative to the natural hormone. The N-terminal residues remain essential for activity, so changes there generally lower potency. Molecular weight sits near 3368 daltons for the tetrasubstituted analog without the linker, while the albumin-binding form is heavier because of the added maleimide group.
CJC-1295 is a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. Its sequence corresponds to the first twenty-nine residues of human GHRH, with four substitutions that slow enzymatic breakdown. Early descriptions placed the compound in research on growth hormone deficiency and related conditions, and later literature groups it with the long-acting GHRH analogs. The name appears in both laboratory and popular fitness writing, where it sometimes labels chemically different peptides.
Rhabdomyolysis (shortened as rhabdo) is a condition in which damaged skeletal muscle breaks down rapidly. Symptoms may include muscle pains, weakness, vomiting, and confusion. There may be tea-colored urine or an irregular heartbeat. Some of the muscle breakdown products, such as the protein myoglobin, are harmful to the kidneys and can cause acute kidney injury. The muscle damage is usually caused by a crush injury, strenuous exercise, medications, or a substance use disorder. Other causes include infections, seizure, electrical injury, heat stroke, prolonged immobilization, lack of blood flow to a limb, or snake bites as well as intense or prolonged exercise, particularly in hot conditions. Rhabdomyolysis can occur in athletes Statins (a class of prescription drugs to lower cholesterol) are considered a small risk. Some people have inherited muscle conditions that increase the risk of rhabdomyolysis. The diagnosis is supported by a urine test strip which is positive for "blood" but the urine contains no red blood cells when examined with a microscope. Blood tests show a creatine kinase activity greater than 1000 U/L, with severe disease being above 5000–15000 U/L. The mainstay of treatment is large quantities of intravenous fluids. Other treatments may include dialysis or hemofiltration in more severe cases. Once urine output is established, sodium bicarbonate and mannitol are commonly used but they are poorly supported by the evidence. Outcomes are generally good if treated early.
Weizmann's political efforts picked up speed, and on 10 December 1914 he met with Herbert Samuel, a British Cabinet member and a secular Jew who had studied Zionism; Samuel believed Weizmann's demands were too modest. Two days later, Weizmann met Balfour again, for the first time since their initial meeting in 1905; Balfour had been out of government ever since his electoral defeat in 1906, but remained a senior member of the Conservative Party in their role as Official Opposition. A month later, Samuel circulated a memorandum entitled The Future of Palestine to his Cabinet colleagues. The memorandum stated: "I am assured that the solution of the problem of Palestine which would be much the most welcome to the leaders and supporters of the Zionist movement throughout the world would be the annexation of the country to the British Empire". Samuel discussed a copy of his memorandum with Nathan Rothschild in February 1915, a month before the latter's death. It was the first time in an official record that enlisting the support of Jews as a war measure had been proposed. Many further discussions followed, including the initial meetings in 1915–16 between Lloyd George, who had been appointed Minister of Munitions in May 1915, and Weizmann, who was appointed as a scientific advisor to the ministry in September 1915. Seventeen years later, in his War Memoirs, Lloyd George described these meetings as being the "fount and origin" of the declaration; historians have rejected this claim.
Cells use glucose for energy. This normally occurs by phosphorylation from the enzyme hexokinase. However, if large amounts of glucose are present (as in diabetes mellitus), hexokinase becomes saturated and the excess glucose enters the polyol pathway when aldose reductase reduces it to sorbitol. This reaction oxidizes NADPH to NADP+. Sorbitol dehydrogenase can then oxidize sorbitol to fructose, which produces NADH from NAD+. Hexokinase can return the molecule to the glycolysis pathway by phosphorylating fructose to form fructose-6-phosphate. However, in uncontrolled diabetics that have high blood glucose - more than the glycolysis pathway can handle - the reactions mass balance ultimately favors the production of sorbitol. Activation of the polyol pathway results in a decrease of reduced NADPH and oxidized NAD+; these are necessary co-factors in redox reactions throughout the body, and under normal conditions they are not interchangeable. The decreased concentration of these NADPH leads to decreased synthesis of reduced glutathione, nitric oxide, myo-inositol, and taurine. Myo-inositol is particularly required for the normal function of nerves. Sorbitol may also glycate nitrogens on proteins, such as collagen, and the products of these glycations are referred-to as AGEs - advanced glycation end-products. AGEs are thought to cause disease in the human body, one effect of which is mediated by RAGE (receptor for advanced glycation end-products) and the ensuing inflammatory responses induced.
In 1996, Osama bin Laden, leading the jihadist organization al-Qaeda, issued his first fatwa, which declared jihad against the United States and demanded expulsion of all American troops stationed in Arabia. Bin Laden interpreted Muhammad as banning non-Muslims from Arabia. He thus considered the U.S. troop presence a provocation to all Muslims. Regarding his holy war, bin Laden stated, "We do not differentiate between those dressed in military uniforms, and civilians; they are all targets of this fatwa." Bin Laden was living in Sudan prior to 1996. When the Sudanese government exiled him after Saudi and U.S. pressure, bin Laden returned to Afghanistan, which was run by the Taliban. They allowed al-Qaeda to use the country as its base of operations. He then orchestrated the 9/11 attacks on the U.S. He personally told his participants to target the World Trade Center and the Pentagon with hijacked planes. He initially denied his role in the attacks, but later recanted his denial. U.S. forces recovered a videotape in which bin Laden, talking to Khaled al-Harbi, admitted foreknowledge of the attacks. In a 2004 video, he confirmed that he had organized 9/11. A video by Al Jazeera in 2006 shows bin Laden with one of the attacks' chief planners, Ramzi bin al-Shibh, as well as hijackers Hamza al-Ghamdi and Wail al-Shehri.
=== General === Peter Atkins & Julio de Paula, 2006, "Physical chemistry," 8th Edn., New York, NY, USA:Macmillan, ISBN 0716787598, accessed 21 June 2015. [E.g., see p. 422 for a group theoretical/symmetry description of atomic orbitals contributing to bonding in methane, CH4, and pp. 390f for estimation of π-electron binding energy for 1,3-butadiene by the Hückel method.] Thomas H. Lowry & Kathleen Schueller Richardson, 1987, Mechanism and Theory in Organic Chemistry, 3rd Edn., New York, NY, USA:Harper & Row, ISBN 0060440848, accessed 20 June 2015. [The authoritative textbook on the subject, containing a number of appendices that provide technical details on molecular orbital theory, kinetic isotope effects, transition state theory, and radical chemistry.] Eric V. Anslyn & Dennis A. Dougherty, 2006, Modern Physical Organic Chemistry, Sausalito, Calif.: University Science Books, ISBN 1891389319. [A modernized and streamlined treatment with an emphasis on applications and cross-disciplinary connections.] Michael B. Smith & Jerry March, 2007, "March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure," 6th Ed., New York, NY, USA:Wiley & Sons, ISBN 0470084944, accessed 19 June 2015. Francis A. Carey & Richard J. Sundberg, 2006, "Advanced Organic Chemistry: Part A: Structure and Mechanisms," 4th Edn., New York, NY, USA:Springer Science & Business Media, ISBN 0306468565, accessed 19 June 2015. Hammett, Louis P. (1940) Physical Organic Chemistry, New York, NY, USA: McGraw Hill, accessed 20 June 2015.
Sources: en.wikipedia.org
Dry ice can be used for loosening asphalt floor tiles or car sound deadening material, making them easy to prise off, as well as freezing water in valveless pipes to enable repair. One of the largest mechanical uses of dry ice is blast cleaning. Dry ice pellets are shot from a nozzle with compressed air, combining the power of the speed of the pellets with the action of the sublimation. This can remove residues from industrial equipment. Examples of materials removed include ink, glue, oil, paint, mold and rubber. Dry ice blasting can replace sandblasting, steam blasting, water blasting or solvent blasting. The primary environmental residue of dry ice blasting is the sublimed CO2, thus making it a useful technique where residues from other blasting techniques are undesirable. Recently, blast cleaning has been introduced as a method of removing smoke damage from structures after fires. Dry ice is also useful for the de-gassing of flammable vapours from storage tanks –the sublimation of dry ice pellets inside an emptied and vented tank causes an outrush of CO2 that carries with it the flammable vapours. The removal and fitting of cylinder liners in large engines requires the use of dry ice to chill and thus shrink the liner so that it freely slides into the engine block. When the liner then warms up, it expands, and the resulting interference fit holds it tightly in place. Similar procedures may be used in fabricating mechanical assemblies with a high resultant strength, replacing the need for pins, keys or welds.
In June 1945, the squadron initially flew missions with the 310th Fighter Squadron, often twice a day, using borrowed U.S. aircraft. It received 25 new P-47D-30-RA aircraft in July, marked with the insignia of both the USAAF and Mexican Air Force. The squadron flew more than 90 combat missions, totaling more than 1,900 hours of flight time. It participated in the Allied effort to bomb Luzon and Formosa to push the Japanese out of those islands. It relentlessly attacked the Japanese forces concentrated mainly in Luzon and flew 53 combat missions as part of the U.S. Air Force warfare organization, was specified in the support of the 25th Infantry Division, the Philippine Army, as well as numerous Filipino guerrillas, to open up into the Cagayan valley where the squadron devastated the Japanese defenses on the ground with its bombs. Close support missions consisted mainly of attacking resistance points, apart from these they launched attacks on bases, fortifications, supply routes and machine gun pits. During its fighting in the Philippines, five squadron pilots died (one was shot down, one crashed, and three ran out of fuel and died at sea); and three others died in accidents during training. The pilot Héctor Espinoza Galván was flying together with an American pilot but he ran out of fuel and fell into the ocean; His body was never found. Captain Pablo Ribaz Martínez and Second Lieutenant Guillermo García Ramos were surrounded by a storm, Ribaz Martínez dying while García Ramos survived after being rescued.
=== Weight loss === Chitosan is marketed in a tablet form as a "fat binder". Although the effect of chitosan on lowering cholesterol and body weight has been evaluated, the effect appears to have no or low clinical importance. Reviews from 2016 and 2008 found there was no significant effect, and no justification for overweight people to use chitosan supplements. In 2015, the U.S. Food and Drug Administration issued a public advisory about supplement retailers who made exaggerated claims concerning the supposed weight loss benefit of various products.
Prioritize agricultural production of a diverse range of nutrient-rich foods; Protect nutrient-rich wild foods and species-rich ecosystems on land and in oceans; Support connectivity of smallholders and Small and Medium Sized Enterprises (SMEs) across food value chains; Redesign safety net/social protection programs towards improved nutritional outcome; Reduce food loss and food waste; Improve food quality and safety; Strengthen regulations for advertising and marketing; Improve transparency in food labeling; Encourage healthier eating through subsidies and promotions of healthy foods and taxes on unhealthy foods; Create consumer demand for healthy foods (nutrition education & civic engagement); Improve acceptability of healthy foods; Promote traditional foods and methods that impart nutritional benefits; Invest in metrics, research, and access to inform policy development.
After repeated experiences with providing prepared rations to soldiers dating from before World War II, Pentagon officials ultimately realized that simply providing a nutritionally balanced meal in the field was not adequate. Service members in various geographic regions and combat situations often required different subsets of ingredients for food to be considered palatable over long periods. Catering to individual tastes and preferences would encourage service members to actually consume the whole ration and its nutrition. Most importantly, the use of specialized forces in extreme environments and the necessity of carrying increasingly heavy field loads while on foot during long missions required significantly lighter alternatives to standard canned wet rations. In 1963, the DoD began developing the "Meal, Ready to Eat", a ration that would rely on modern food preparation and packaging technology to create a lighter replacement for the canned MCI. In 1966, this led to the Long Range Patrol, or LRP ration, a dehydrated meal stored in a waterproof canvas pouch. As with the Jungle ration, its expense compared to canned wet rations, as well as the costs of stocking and storing a specialized field ration, led to its limited usage and repeated attempts at discontinuance by Quartermaster Command officials. Early MRE prototypes that involved freeze-dried and dehydrated foods were developed under Abdul Rahman, who later received the Meritorious Civilian Service Award for his work.
Sources: en.wikipedia.org
An insulin pump allows the replacement of slow-acting insulin for basal needs with a continuous infusion of rapid-acting insulin. The insulin pump delivers a single type of rapid-acting insulin in two ways:
=== Acute exposures === In case reports of humans intentionally or accidentally ingesting high concentrations of copper salts (doses usually not known but reported to be 20–70 grams of copper), a progression of symptoms was observed including abdominal pain, headache, nausea, dizziness, vomiting and diarrhea, tachycardia, respiratory difficulty, hemolytic anemia, hematuria, massive gastrointestinal bleeding, liver and kidney failure, and death. Episodes of acute gastrointestinal upset following single or repeated ingestion of drinking water containing elevated levels of copper (generally above 3–6 mg/L) are characterized by nausea, vomiting, and stomach irritation. These symptoms resolve when copper in the drinking water source is reduced. Three experimental studies were conducted that demonstrate a threshold for acute gastrointestinal upset of approximately 4–5 mg/L in healthy adults, although it is not clear from these findings whether symptoms are due to acutely irritant effects of copper and/or to metallic, bitter, salty taste. In an experimental study with healthy adults, the average taste threshold for copper sulfate and chloride in tap water, deionized water, or mineral water was 2.5–3.5 mg/L. This is just below the experimental threshold for acute gastrointestinal upset.
== See also == Outline of the Yemeni crisis, revolution, and civil war (2011–present) South Yemen insurgency COVID-19 pandemic in Yemen Yemen cholera outbreak Health in Yemen Famine in Yemen (2016-present)
=== Ovulation === NGF is abundant in seminal plasma. Recent studies have found that it induces ovulation in some mammals e.g. "induced" ovulators, such as llamas. Surprisingly, research showed that these induced animals will also ovulate when semen from on-schedule or "spontaneous" ovulators, such as cattle is used. Its significance in humans is unknown. It was previously dubbed ovulation-inducing factor (OIF) in semen before it was identified as beta-NGF in 2012.
Sources: en.wikipedia.org
No. It is a laboratory-synthesized analog built on a fragment of the natural hormone. The natural peptide is shorter-lived and lacks the stabilizing substitutions found in the synthetic version.
DAC stands for drug affinity complex, a chemical group that binds the peptide to serum albumin. The binding slows clearance and lengthens the time the molecule stays in plasma compared with the unmodified analog.
Because two distinct molecules are discussed under one informal label. The albumin-binding version clears over several days, while the form without that group clears within roughly half an hour. Mixing results from both creates inconsistent figures.
It is a synthetic peptide analogue of growth hormone-releasing hormone. Four substitutions in its sequence make it more resistant to enzymatic degradation than the natural hormone. In the version carrying a drug affinity complex, the peptide binds albumin and remains in circulation for days.