This is a working overview of DAC, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-10-07 and is reviewed periodically as new material appears.
Lyophilized material is generally stable for extended periods when held at minus twenty degrees Celsius or below and protected from moisture and light. In solution the peptide is more labile; bond hydrolysis, aggregation and oxidation of susceptible residues all proceed faster at ambient temperature. Repeated freeze and thaw cycles should be avoided because they promote clumping and loss of soluble material. The conjugated variant adds a further consideration, since the maleimide group can hydrolyze in aqueous buffer and lose its ability to react with albumin.
Laboratory handling centers on minimizing exposure to water, heat and oxygen before use. Working solutions are typically prepared in sterile water or a mild buffer, and any residual particulate matter is removed by filtration. When the powder dissolves slowly, a small proportion of acetonitrile or dilute acetic acid is sometimes added as a co-solvent. Containers are kept sealed and desiccated between uses. Records of lot number, reconstitution date and storage conditions support later comparison of results across experiments.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off white powder | Typical lyophilized form |
| Water solubility | Soluble | May need a small organic co-solvent |
| Purity assessment | Chromatographic peak area | Most certificates report a percentage figure |
| Storage temperature | Minus 20 C or lower | Dry, dark, sealed container |
| Identity check | Electrospray mass spectrometry | Compared against theoretical mass |
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.
CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone, constructed on the 29-amino-acid fragment designated GRF(1-29). The name began as an internal development code during the 1990s and later spread through research supply catalogs and discussion forums. The molecule does not occur in nature; its sequence is engineered rather than isolated from tissue. Two related compounds are sold under this single label, and they differ by one appended chemical group that strongly influences how long the peptide remains in circulation.
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.
Stability depends heavily on physical state. A lyophilized powder kept dry, desiccated, and shielded from light typically holds its integrity for months to years at minus twenty degrees Celsius, and longer at minus eighty. Once dissolved, the peptide becomes far more vulnerable, since peptide bond hydrolysis, oxidation of susceptible residues, and aggregation all proceed faster in solution. Buffers near neutral pH are generally gentler than strongly acidic or alkaline conditions. Repeated freeze-thaw cycles and exposure to air-liquid interfaces during vigorous mixing cause losses that are easy to overlook.
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.
=== Panic disorder === Sertraline is superior to placebo for the treatment of panic disorder. The response rate was independent of the dose. In addition to decreasing the frequency of panic attacks by about 80% (vs. 45% for placebo) and decreasing general anxiety, sertraline resulted in an improvement in quality of life on most parameters. The patients rated as "improved" on sertraline reported better quality of life than the ones who "improved" on placebo. The authors of the study argued that the improvement achieved with sertraline is different and of a better quality than the improvement achieved with a placebo. Sertraline is equally effective for men and women, and for patients with or without agoraphobia. Previous unsuccessful treatment with benzodiazepines does not diminish its efficacy. However, the response rate was lower for the patients with more severe panic. Starting treatment simultaneously with sertraline and clonazepam, with subsequent gradual discontinuation of clonazepam, may accelerate the response. Double-blind comparative studies found sertraline to have the same effect on panic disorder as paroxetine or imipramine. While imprecise, comparison of the results of trials of sertraline with separate trials of other anti-panic agents (clomipramine, imipramine, clonazepam, alprazolam, and fluvoxamine) indicates approximate equivalence of these medications.
European ancestry being dominant according to all autosomal studies undertaken covering the population, accounting for between 60% and 65% of the average genetic makeup of the Brazilian population. African ancestry among the Brazilians is estimated at 20% to 25% of the average genetic makeup Indigenous ancestry is significant and present in all regions of Brazil, accounting for around 15% to 20% of the average genetic ancestry of Brazilians. From the 19th century, Brazil opened its borders to immigration. About five million people from over 60 countries migrated to Brazil between 1808 and 1972, most of them of Portuguese, Italian, Spanish, German, English, Ukrainian, Polish, Jewish, African, Armenian, Russian, Chinese, Japanese, Korean and Arab origin. Brazil has the second-largest Jewish community in Latin America after Argentina making up 0.06% of its population. Outside of the Arab world, Brazil also has the largest population of Arab ancestry in the world, with 15–20 million people. According to Brazil's Ministry of Foreign Affairs, Brazil is home to a Lebanese diaspora of 7-10 million, surpassing the population of Lebanese individuals residing in Lebanon. Brazilian society is more markedly divided by social class lines, although a high income disparity is found between race groups, so racism and classism often overlap.
== Causes == Childhood obesity can be brought on by a range of factors which often act in combination. "Obesogenic environment" refers to a mixture of environmental factors that are permissive of obesity, especially for those who are genetically predisposed. The greatest risk factor for child obesity is the obesity of both parents. This may be reflected by the family's environment and genetics. Other reasons may also be due to psychological factors and the child's body type. A 2010 review stated that childhood obesity likely is the result of the interaction of natural selection favouring those with more parsimonious energy metabolism and today's consumerist society with easy access to cheap, energy-dense foods and less energy requirements in daily life. Factors include the increase in use of technology, increase in snacks and portion size of meals, and the decrease in the physical activity of children. A study found that children who use electronic devices three or more hours a day had between a 17–44% increased risk of being overweight, or a 10–61% increased risk of obesity (Cespedes 2011). Childhood obesity is common among children from low-income, African American and Hispanic communities. This is mainly because minority children spend less time playing outside the house and staying active. Parents may prefer their children stay inside the home because they fear gang and drug violence and other dangers.
Sources: en.wikipedia.org
=== Branched-chain amino acids === Several studies have attempted to decrease the synthesis of serotonin by administering branched-chain amino acids and inhibiting the transport of tryptophan across the blood brain barrier. The studies performed resulted in little or no change in performance between increased BCAA intake and placebo groups. One study in particular administered a carbohydrate solution and a carbohydrate + BCAA solution. Both of the groups were able to run for longer before fatigue compared to the water placebo group. However, both the carbohydrate and the carbohydrate + BCAA groups had no differences in their performance. Branch-chained amino acid supplementation has proven to have little to no effect on performance. There has been little success utilizing neurotransmitter precursors to control central nervous system fatigue. One review hypothesized that the inconsistency with BCAA administration was the result of ammonia accumulation as a result of increased BCAA oxidation.
=== Other honours === Crick was elected a Fellow of the Royal Society (FRS) in 1959, a Fellow of the International Academy of Humanism, and a Fellow of CSICOP. In 1987, Crick received the Golden Plate Award of the US Academy of Achievement. The inscription on the helices of a DNA sculpture (which was donated by James Watson) outside Thirkill Court, Clare College, Cambridge, reads: "The structure of DNA was discovered in 1953 by Francis Crick and James Watson while Watson lived here at Clare." and on the base: "The double helix model was supported by the work of Rosalind Franklin and Maurice Wilkins." Another sculpture entitled Discovery, by artist Lucy Glendinning, was installed on 13 December 2005 in Abington Street, Northampton. According to the late Lynn Wilson, chairman of the Wilson Foundation, "The sculpture celebrates the life of a world class scientist who must surely be considered the greatest Northamptonian of all time — by discovering DNA he unlocked the whole future of genetics and the alphabet of life." Westminster City Council unveiled a green plaque to Francis Crick on the front façade of 56 St George's Square, Pimlico, London SW1 on 20 June 2007; Crick lived in the first floor flat, together with Robert Dougall of BBC radio and later TV fame, a former Royal Navy associate. At a meeting of the executive council of the Committee for Skeptical Inquiry (CSI) (formerly CSICOP) in Denver, Colorado in April 2011, Crick was selected for inclusion in CSI's Pantheon of Skeptics.
=== Others === Untitled submarine game: one of Valve's earliest game ideas was for a submarine game, with Valve co-founder Mike Harrington seeing an opportunity to create "fantastic underwater visuals and gameplay". It is unknown whether it ever advanced beyond the conceptual stage. Prospero: a third-person exploration game with a science fantasy theme. The project was in development at the same time as Half-Life. Prospero's development team transitioned to work on Half-Life, which had gained more traction. Untitled role-playing game (I): a fantasy, action role-playing game about fairies that was in a prototype phase and cancelled prior to Left 4 Dead's release. The Crossing: a first-person shooter developed in collaboration with Arkane Studios. The project was announced in 2007 and put on hold in May 2009. Stars of Blood: a space pirate game. In November 2012, Newell revealed the project's name and confirmed that it was no longer in development. Left 4 Dead 3: an open-world sequel to Left 4 Dead 2 that was set in Morocco. It was cancelled when it became clear that the Source 2 engine was not yet ready to support full-scale game development. Hot Dog: another attempt at creating a Left 4 Dead game, codenamed so that fans would not recognize it if its name were leaked. Untitled role-playing game (II): a fantasy RPG that was inspired by The Elder Scrolls, Dark Souls, and Monster Hunter series. It was at one point resurrected as a single-player RPG about the Dota 2 character Axe before it was shelved again.
Although sublingual administration of estradiol has a relatively short duration, the medication can be administered multiple times per day in divided doses to compensate for this. Studies that used high doses of sublingual estradiol in the treatment of severe postpartum depression have administered a dose of 1 mg 3 to 8 times per day. In one study, which administered a mean total dosage of sublingual estradiol of 4.8 mg/day, estradiol levels remained elevated at about 130 pg/mL on average in the morning before the first dose of the day. Oral micronized estradiol valerate tablets can be taken sublingually as well. The administration of 2 mg oral micronized estradiol valerate tablets (Progynova, Schering) sublingually 3 or 4 times per day resulted in circulating estradiol levels of about 290 pg/mL to 460 pg/mL in premenopausal women (time of measurements not given). Steady-state levels of estradiol were achieved within about 5 or 6 days. Levels of progesterone, luteinizing hormone, and follicle-stimulating hormone were all considerably suppressed, and ovulation, as well as the associated mid-cycle hormonal surges, were prevented. Sublingual estradiol valerate is used for cycle control in egg donation and surrogacy in cisgender women and is used in hormone therapy for transgender women. Cyclodextrin-containing formulations of sublingual estradiol with improved water solubility and absorption have been developed and studied.
Sources: en.wikipedia.org
A laboratory information management system (LIMS), sometimes referred to as a laboratory information system (LIS) or laboratory management system (LMS), is a software-based solution with features that support a modern laboratory's operations. They tend to be handled by inventory laboratory technicians. Key features include—but are not limited to—workflow and data tracking support, flexible architecture, and data exchange interfaces, which fully "support its use in regulated environments". The features and uses of a LIMS have evolved over the years from simple sample tracking to an enterprise resource planning tool that manages multiple aspects of laboratory informatics. There is no useful definition of the term "LIMS" as it is used to encompass a number of different laboratory informatics components. The spread and depth of these components is highly dependent on the LIMS implementation itself. All LIMSs have a workflow component and some summary data management facilities but beyond that there are significant differences in functionality. Historically the LIMyS, LIS, and process development execution system (PDES) have all performed similar functions. The term "LIMS" has tended to refer to informatics systems targeted for environmental, research, or commercial analysis such as pharmaceutical or petrochemical work. "LIS" has tended to refer to laboratory informatics systems in the forensics and clinical markets, which often required special case management tools.
In the US, esketamine (brand name Spravato) is a nasal spray indicated, as monotherapy, or in conjunction with an oral antidepressant as a therapy for treatment-resistant depression (TRD) as well as major depressive disorder (MDD) associated with suicidal ideation or behavior in adults. In the clinical trials that led to approval of esketamine, TRD was defined as major depressive disorder with inadequate response to at least two different conventional antidepressants. The nasal spray formulation of esketamine used for depression delivers two sprays containing a total of 28 mg esketamine and doses of 56 mg (2 devices) to 84 mg (3 devices) are used. Esketamine has modest short-term efficacy on TRD (similar in efficacy to atypical antipsychotics); there is limited long-term safety data available and some concerning signals regarding adverse events and abuse potential. Due to concerns about sedation, dissociation, and misuse, esketamine is available for treatment of depression only from certified providers through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called Spravato REMS.
Carrier Global Corporation is an American multinational heating, ventilation, and air conditioning (HVAC), refrigeration, and fire and security equipment corporation based in Palm Beach Gardens, Florida. Carrier was founded in 1915 as an independent company manufacturing and distributing HVAC systems, and has since expanded to include manufacturing commercial refrigeration and food service equipment, and fire and security technologies. As of 2022, it was a $20.4 billion company with over 52,000 employees serving customers in 160 countries on six continents. Carrier was acquired by United Technologies in 1979, but it was spun off as an independent company 41 years later in 2020, as was the Otis Elevator Company.
== Portrayals in television == Television is in over 90% of U.S. households and in 1995 it had a strong influence on how viewers perceive the world. In terms of mental illness portrayals, television has been a pioneer in representing these illnesses across thousands of programs in nearly a century's worth of content. The media often depicts people with mental illness as violent or unpredictable, creating misrepresentations and harmful stereotypes. Research shows that viewers who watch more television are more likely to have negative views about mental health. Although television has frequently misrepresented mental health, there has been a growing shift towards more accurate and honest portrayals.
11B Infantryman (includes soldiers formerly designated 11M [Mechanized] and 11H [Anti-armor]) 11B Infantryman is the basic infantry soldier MOS of the US Army. 11C Indirect Fire Infantryman (Mortarman) 11X Undetermined Infantry (Open Enlistment Option, B/C determined during training.) 11Z Infantry Senior Sergeant
Sources: en.wikipedia.org
The mass difference from the linker is large enough for routine detection by mass spectrometry. The unconjugated form gives a single sharp signal at its expected weight. Material that has already reacted with albumin shows a much higher mass and a broadened chromatographic peak.
Yes. Degradation proceeds faster once the powder is dissolved, especially at room temperature or after multiple freeze and thaw cycles. Working solutions are often aliquoted to avoid repeated handling. Lyophilized powder held cold and dry retains its properties far longer.
Truncated sequences, oxidized residues and aggregated forms can all elute near the main peak. Reversed phase chromatography resolves many of these species, so the number of peaks is a useful indicator of synthesis quality. A single peak does not by itself prove correct sequence, which is why mass confirmation is paired with it.
The powder is normally held at minus twenty degrees Celsius or below. Light and moisture exposure should be minimized. Repeated warming and cooling cycles are avoided.