This is a working overview of purity, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-10-15 and is reviewed periodically as new material appears.
Naming in this area is inconsistent, and readers should treat product labels with care. In much of the literature and in vendor catalogs, the unqualified term refers to the albumin-binding version, while the version lacking the DAC group appears as modified GRF(1-29), mod GRF(1-29), or the same name with a without-DAC qualifier. Because one abbreviation has been applied to both materials, the only reliable way to identify a sample is to check the stated sequence and the presence of the linker.
CJC-1295 is the name used for a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound was described by a Canadian drug discovery company in the mid-2000s as a long-acting research tool. Two closely related molecules share the name in practice: one carries a drug affinity complex, or DAC, group, and one does not. The distinction matters because the two behave differently in circulation.
The peptide backbone corresponds to GRF(1-29), the first 29 residues of native growth hormone-releasing hormone, which retains most of the receptor-activating activity of the full-length molecule. Four substitutions distinguish the analog from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes slow cleavage by dipeptidyl peptidase IV, the enzyme that degrades native hormone in plasma within minutes. The outcome is improved enzymatic stability combined with a still brief residence time when no additional modification is present.
Downstream of growth hormone, the liver and other tissues increase production of insulin-like growth factor 1, a mediator of many growth-promoting effects. Studies have documented elevated levels of both hormones after dosing, and the rise from the long-acting form persists longer than that produced by shorter-acting analogues. What remains unclear is whether sustained elevation of these markers translates into meaningful clinical benefit, and whether prolonged exposure carries risks that short trials could not detect.
CJC-1295 acts at the growth hormone-releasing hormone receptor, a G-protein-coupled receptor found on somatotroph cells in the anterior pituitary. Binding triggers a rise in cyclic AMP and calcium entry, which promotes release of stored growth hormone. Because the peptide mimics the body's own releasing hormone, it amplifies existing secretory pulses rather than driving continuous output. The size of the response therefore depends partly on the subject's own hormonal rhythm and feedback state.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | GHRH analog, not a steroid |
| Backbone length | 29 amino acids | Based on GRF(1-29) |
| Substitutions | Four positions | D-Ala2, Gln8, Ala15, Leu27 |
| Appearance | White to off-white powder | Typical lyophilized research material |
| Common synonyms | Modified GRF(1-29) | Usage varies between sources |
Batch-to-batch consistency depends on solid-phase peptide synthesis and subsequent purification. Coupling efficiency, resin choice, and cleavage conditions all affect the final profile. Counter-ion content and moisture can shift the apparent mass of a batch. Documentation typically includes a certificate of analysis with chromatograms and spectra. Independent verification by a second laboratory is sometimes requested. Whether a given certificate reflects the actual vial contents depends on chain of custody. Analytical methods themselves carry uncertainty that should be stated alongside results.
Lyophilized material is typically stored at minus twenty degrees Celsius or lower. Keeping the vial dry and protected from light preserves peptide integrity. Repeated freeze-thaw cycles can cause aggregation or loss of activity. Once dissolved, solutions are generally kept at two to eight degrees Celsius. Stability data for reconstituted solutions vary, and long-term behavior is not fully established. Working aliquots reduce the number of times a stock container is opened.
Reverse-phase high-performance liquid chromatography is the standard tool for purity assessment. The technique separates the target peptide from truncated or modified byproducts. Mass spectrometry confirms molecular weight and supports sequence verification. Electrospray ionization and matrix-assisted laser desorption are both used. Amino acid analysis provides an independent check on composition. Purity values are commonly reported as area percentage from the chromatogram. Residual trifluoroacetate and water content are also measured in many quality programs.
The second form adds a maleimide-bearing linker to the lysine at the carboxyl end. This group reacts with cysteine-34 on circulating serum albumin, forming a covalent bond that keeps the peptide in the bloodstream for far longer. ConjuChem developed the molecule as a way to extend the action of a peptide without frequent administration. The albumin attachment is the defining structural feature of the drug affinity complex version. Whether continuous exposure produces effects distinct from shorter pulses remains an unresolved research question.
CJC-1295 belongs to a family of synthetic peptides modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound is built from the first twenty-nine amino acids of the natural human sequence, a fragment that retains full receptor binding capacity. Native growth hormone-releasing hormone is degraded quickly in circulation, so the fragment alone has limited practical value. Early work therefore focused on chemical modifications that preserve receptor binding while slowing enzymatic breakdown. The result is a molecule described in the literature as a long-acting analog of the natural hormone.
=== R139w === One further single nucleotide polymorphism, found homozygous in 0% to 5% of different ethnic population, is leading to an amino acid exchange on position 139 from arginine to tryptophane. Furthermore, an alternative RNA splicing site is created leading to a loss of the quinone binding site. The variant protein of NQO1*3 has similar stability as its wild-type counterpart. The variation between the two is substrate specific and it has reduced activity for some substrates. It has been recently shown that the NQO1*3 polymorphism may also lead to reduced NQO1 protein expression.
On 4 December 2024, the Lebanese Health Ministry reported that since 7 October 2023, Israeli attacks killed 4,047 people, including 316 children and 790 women, and injured 16,638 others. Among the dead were at least 41 Lebanese Army soldiers and more than 200 medics. Several UNIFIL workers and peacekeepers were injured in numerous attacks by both Israel and Lebanese militias. By 25 November 2025, the Lebanese Health Ministry reported that Israeli attacks during the ceasefire had killed 331 people and injured 945. The UN said that at least 127 fatalities were civilians. At the height of the conflict in October 2024, more than 1.2 million Lebanese were displaced, including between 200,000 and 300,000 who fled into Syria.
Low-level waste (LLW) is generated from hospitals and industry, as well as the nuclear fuel cycle. Low-level wastes include paper, rags, tools, clothing, filters, and other materials which contain small amounts of mostly short-lived radioactivity. Materials that originate from any region of an active area are commonly designated as LLW as a precautionary measure even if there is only a remote possibility of being contaminated with radioactive materials. Such LLW typically exhibits no higher radioactivity than one would expect from the same material disposed of in a non-active area, such as a normal office block. Example LLW includes wiping rags, mops, medical tubes, laboratory animal carcasses, and more. LLW makes up 94% of all radioactive waste volume in the UK. Most of it is disposed of in Cumbria, first in landfill style trenches, and now using grouted metal containers that are stacked in concrete vaults. A new site in the north of Scotland is the Dounreay site which is prepared to withstand a 4m tsunami.[1] Some high-activity LLW requires shielding during handling and transport but most LLW is suitable for shallow land burial. To reduce its volume, it is often compacted or incinerated before disposal. Low-level waste is divided into four classes: class A, class B, class C, and Greater Than Class C (GTCC).
=== Phase III ACHIEVE-1 trial === In April 2025, results from a phase III clinical trial involving 559 people with type 2 diabetes who took an oral orforglipron pill or a placebo daily for 40 weeks showed that orforglipron produced a reduction of hemoglobin A1C level by 1.3 to 1.6 percentage points from a starting level of 8%. More than 65% of participants taking the highest dose of orforglipron achieved a reduction of hemoglobin A1C level by more than or equal to 1.5 percentage points, bringing them into the non-diabetic range as defined by the American Diabetes Association. People taking the highest dose of the pill lost 8% of their weight, or around 16 lb (7.3 kg), on average after 40 weeks. In its press release, Lilly noted that the subjects' weight loss had not yet plateaued at the time the trial concluded, and suggested that this indicated that greater weight reduction would ultimately be achieved with extended therapy. Side effects were similar to those seen with other GLP-1 agonists, and no significant liver problems were observed.
=== Pattern-based measures === Earlier methods for measuring convergence incorporate ratios of phenotypic and phylogenetic distance by simulating evolution with a Brownian motion model of trait evolution along a phylogeny. More recent methods also quantify the strength of convergence. One drawback to keep in mind is that these methods can confuse long-term stasis with convergence due to phenotypic similarities. Stasis occurs when there is little evolutionary change among taxa. Distance-based measures assess the degree of similarity between lineages over time. Frequency-based measures assess the number of lineages that have evolved in a particular trait space.
Sources: en.wikipedia.org
Equilibrium chemistry is concerned with systems in chemical equilibrium. The unifying principle is that the free energy of a system at equilibrium is the minimum possible, so that the slope of the free energy with respect to the reaction coordinate is zero. This principle, applied to mixtures at equilibrium provides a definition of an equilibrium constant. Applications include acid–base, host–guest, metal–complex, solubility, partition, chromatography and redox equilibria.
Vegans had a lower dietary intake of vitamin D and lower serum 25(OH)D when compared to omnivores, with lacto-ovo-vegetarians falling in between due to the vitamin content of egg yolks and fortified dairy products. Governments have mandated or voluntary food fortification programs to bridge the difference in, respectively, 15 and 10 countries. The US is one of the few mandated countries. The original fortification practices, circa the early 1930s, were limited to cow's milk, which had a large effect on reducing infant and child rickets. In July 2016 the US Food and Drug Administration approved the addition of vitamin D to plant milk beverages intended as milk alternatives, such as beverages made from soy, almond, coconut, and oats. At an individual level, people may choose to consume a multivitamin/mineral product or else a vitamin-D-only product. There are many disease states, medical treatments, and medications that put people at risk for vitamin D deficiency. Chronic diseases that increase risk include kidney and liver failure, Crohn's disease, inflammatory bowel disease, and malabsorption syndromes such as cystic fibrosis, and hyper- or hypo-parathyroidism. Obesity sequesters vitamin D in fat tissues, thereby lowering serum levels, but bariatric surgery to treat obesity interferes with dietary vitamin D absorption, also causing deficiency. Medications interacting with vitamin D metabolism include antiretrovirals, anti-seizure drugs, glucocorticoids, systemic antifungals such as ketoconazole, cholestyramine, and rifampicin.
=== Stage V: Sequelae === The disease is over, but sequelae from the gangrenous and scarring stages remain. Tissue may be missing, teeth may still be exposed, and the face may be disfigured. The patient may have difficulty eating, drinking, and speaking. Teeth may become set in the wrong places, or be lost altogether. There may still be problems with drooling and with opening/closing the jaw. Reconstructive surgery is an option at this phase. Social reintegration is also very important.
ATP is the phosphorylated version of adenosine diphosphate (ADP), which stores energy in a cell and powers most cellular activities. ATP is the energized form, while ADP is the (partially) depleted form. NADP+ is an electron carrier which ferries high energy electrons. In the light reactions, it gets reduced, meaning it picks up electrons, becoming NADPH.
This poses a real challenge for the translators because they have to render the meaning, i.e. find an equivalent, of a very specific, scientific term in the target language and frequently the narrator uses a more general name instead of a specific term and the translator has to rely on the image presented in the programme to understand which term is being discussed in order to transpose it in the target language accordingly. Additionally, translators of minorised languages often face another problem: some terms may not exist in the target language. In such cases, they have to create new terminology or consult specialists to find proper solutions. Also, sometimes the official nomenclature differs from the terminology used by actual specialists, which leaves the translator to decide between using the official vocabulary that can be found in the dictionary, or rather opting for spontaneous expressions used by real experts in real-life situations.
Sources: en.wikipedia.org
Uncle Burger: large beef patty (5 ounces (140 g)), red onion slice, pickles, ketchup, Chubby mayo, Uncle Sauce, lettuce, tomato, sesame seed bun, cheese slice x2 Double Teen Burger regular beef patty (3 ounces (85 g)×2), onion slice, pickles, ketchup, mustard, bacon, Teen Sauce, lettuce, tomato, sesame seed bun, cheese slice Discontinued members of the Burger Family include the Grandma Burger, a prime rib burger topped with caramelized onions and horseradish sauce; and the Sirloin Burger Twins, which were a pair of sliders.
On 5 October 1959, Trieste departed San Diego for Guam aboard the freighter Santa Maria to participate in Project Nekton, a series of very deep dives in the Mariana Trench. On 23 January 1960, Trieste reached the ocean floor in the Challenger Deep (the deepest southern part of the Mariana Trench), carrying Jacques Piccard (son of Auguste) and Lieutenant Don Walsh, USN. This was the first time a vessel, crewed or uncrewed, had reached the deepest point in the Earth's oceans. The onboard systems indicated a depth of 11,521 metres (37,799 ft), although this was later revised to 10,916 metres (35,814 ft) and more accurate measurements made in 1995 have found the Challenger Deep slightly shallower, at 10,911 metres (35,797 ft). Building a pressure hull is difficult, as it must withstand pressures at its required diving depth. When the hull is perfectly round in cross-section, the pressure is evenly distributed, and causes only hull compression. If the shape is not perfect, the hull deflects more in some places and buckling instability is the usual failure mode. Inevitable minor deviations are resisted by stiffener rings, but even a one-inch (25 mm) deviation from roundness results in over 30 percent decrease of maximal hydrostatic load and consequently dive depth. The hull must therefore be constructed with high precision. All hull parts must be welded without defects, and all joints are checked multiple times with different methods, contributing to the high cost of modern submarines.
Adenosine triphosphate (ATP) is a nucleoside triphosphate that provides free energy of approximately 58 kJ/mol (0.6 eV) to drive and support many processes in living cells, such as muscle contraction, nerve impulse propagation, and chemical synthesis. Found in all known forms of life, it is often referred to as the "molecular unit of currency" for intracellular energy transfer. When consumed in a metabolic process, ATP converts either to adenosine diphosphate (ADP) or to adenosine monophosphate (AMP). Other processes, such as oxidative phosphorylation or substrate-level phosphorylation, regenerate ATP. ATP is also a precursor to DNA and RNA, and is used as a coenzyme. Daily, an average adult human recycles through synthesis and hydrolysis around 50 kilograms of ATP (about 100 moles). From the perspective of biochemistry, ATP is classified as a nucleoside triphosphate, which indicates that it consists of three components: a nitrogenous base (adenine), the sugar ribose, and the triphosphate.
The carbon exchange between atmospheric CO2 and carbonate at the ocean surface is also subject to fractionation, with 14C in the atmosphere more likely than 12C to dissolve in the ocean. The result is an overall increase in the 14C/12C ratio in the ocean of 1.5%, relative to the 14C/12C ratio in the atmosphere. This increase in 14C concentration almost exactly cancels out the decrease caused by the upwelling of water (containing old, and hence 14C-depleted, carbon) from the deep ocean, so that direct measurements of 14C radiation are similar to measurements for the rest of the biosphere. Correcting for isotopic fractionation, as is done for all radiocarbon dates to allow comparison between results from different parts of the biosphere, gives an apparent age of about 400 years for ocean surface water.
Sources: en.wikipedia.org
No. It is a laboratory-made analog of growth hormone-releasing hormone. The natural hormone is a 44-residue peptide, while the analog is built on a shorter 29-residue fragment.
The original material included a linker that binds serum albumin. A later variant removed that linker to reduce the duration of action. Catalogs and papers did not consistently adopt separate names, so both remain widely labeled with the same term.
The amino acid sequence and the presence or absence of the linker group. Mass measured by spectrometry gives an independent check that separates the two forms.
It binds the growth hormone-releasing hormone receptor on pituitary somatotroph cells. Receptor activation raises cyclic AMP and promotes release of stored growth hormone granules. Because the peptide persists longer than natural releasing hormone, stimulation is prolonged rather than brief.