title: Acute myeloid leukemia

text: Enlargement of the spleen may occur in AML, but it is typically mild and asymptomatic. Lymph node swelling is rare in most types of AML, except for acute myelomonocytic leukemia (AMML). The skin can be involved in the form of leukemia cutis; Sweet's syndrome; or non-specific findings: flat lesions (macules), raised lesion papules), pyoderma gangrenosum and vasculitis.


title: Acute myeloid leukemia

text: Some people with AML may experience swelling of the gums because of infiltration of leukemic cells into the gum tissue. Involvement of other parts of the body such as the gastrointestinal tract, respiratory tract and other parts is possible but less common. One area which has particular importance for treatment is whether there is involvement of the meninges around the central nervous system.


title: Acute myeloid leukemia

text: Most cases of AML do not have exposure to any identified risk factors. However, a number of risk factors for developing AML have been identified. These include other blood disorders, chemical exposures, ionizing radiation, and genetic risk factors. Where a defined exposure to past chemotherapy, radiotherapy, toxin or hematologic malignancy is known, this is termed "secondary AML".


title: Acute myeloid leukemia

text: Other blood disorders, particularly myelodysplastic syndrome (MDS) and less commonly myeloproliferative neoplasms (MPN), can evolve into AML; the exact risk depends on the type of MDS/MPN. The presence of asymptomatic clonal hematopoiesis also raises the risk of transformation into AML.


title: Acute myeloid leukemia

text: Exposure to anticancer chemotherapy, in particular alkylating agents, can increase the risk of subsequently developing AML. Other chemotherapy agents, including fludarabine, and topoisomerase II inhibitors are also associated with the development of AML; most commonly after 4–6 years and 1–3 years respectively. These are often associated with specific chromosomal abnormalities in the leukemic cells.


title: Acute myeloid leukemia

text: Other chemical exposures associated with the development of AML include benzene, chloramphenicol and phenylbutazone.


title: Acute myeloid leukemia

text: High amounts of ionizing radiation exposure, such as that used for radiotherapy used to treat some forms of cancer, can increase the risk of AML. People treated with ionizing radiation after treatment for prostate cancer, non-Hodgkin lymphoma, lung cancer, and breast cancer have the highest chance of acquiring AML, but this increased risk returns to the background risk observed in the general population after 12 years. Historically, survivors of the atomic bombings of Hiroshima and Nagasaki had an increased rate of AML, as did radiologists exposed to high levels of X-rays prior to the adoption of modern radiation safety practices.


title: Acute myeloid leukemia

text: Most cases of AML arise spontaneously, however there are some genetic mutations associated with an increased risk. Several congenital conditions increase the risk of leukemia; the most common is Down syndrome, with other more rare conditions including Fanconi anemia, Bloom syndrome and ataxia-telangiectasia (all characterised by problems with DNA repair), and Kostmann syndrome.


title: Acute myeloid leukemia

text: Being overweight and obese increase the risk of developing AML, as does any amount of active smoking. For reasons that may relate to substance or radiation exposure, certain occupations have a higher rate of AML; particularly work in the nuclear power industry, electronics or computer manufacturing, fishing and animal slaughtering and processing.


title: Acute myeloid leukemia

text: The malignant cell in AML is the myeloblast. In normal development of blood cells (hematopoiesis), the myeloblast is an immature precursor of myeloid white blood cells; a normal myeloblast will mature into a white blood cell such as an eosinophil, basophil, neutrophil or monocyte. In AML, though, a single myeloblast accumulates genetic changes which stop maturation, increase its proliferation, and protect it from programmed cell death (apoptosis). Much of the diversity and heterogeneity of AML is because leukemic transformation can occur at a number of different steps along the differentiation pathway. Genetic abnormalities or the stage at which differentiation was halted form part of modern classification systems.


title: Acute myeloid leukemia

text: Specific cytogenetic abnormalities can be found in many people with AML; the types of chromosomal abnormalities often have prognostic significance. The chromosomal translocations encode abnormal fusion proteins, usually transcription factors whose altered properties may cause the "differentiation arrest". For example, in APL, the t(15;17) translocation produces a PML-RARA fusion protein which binds to the retinoic acid receptor element in the promoters of several myeloid-specific genes and inhibits myeloid differentiation.


title: Acute myeloid leukemia

text: The clinical signs and symptoms of AML result from the growth of leukemic clone cells, which tends to interfere with the development of normal blood cells in the bone marrow. This leads to neutropenia, anemia, and thrombocytopenia. Other symptoms can arise from the infiltration of malignant cells into parts of the body, such as the gingiva and skin.


title: Acute myeloid leukemia

text: Many cells develop mutations in genes that affect epigenetics, such as DNA methylation. When these mutations occur, it is likely in the early stages of AML. Such mutations include in the DNA demethylase "TET2" and the metabolic enzymes "IDH1" and "IDH2", which lead to the generation of a novel oncometabolite, "D"-2-hydroxyglutarate, which inhibits the activity of epigenetic enzymes such as "TET2". Epigenetic mutations may lead to the silencing of tumor suppressor genes and/or the activation of proto-oncogenes.


title: Acute myeloid leukemia

text: A complete blood count, which is a blood test, is one of the initial steps in the diagnosis of AML. It may reveal both an excess of white blood cells (leukocytosis) or a decrease (leukopenia), and a low red blood cell count (anemia) and low platelets (thrombocytopenia) can also be commonly seen. A blood film may show leukemic blast cells. Inclusions within the cells called Auer rods, when seen, make the diagnosis highly likely. A definitive diagnosis requires a bone marrow aspiration and biopsy.


title: Acute myeloid leukemia

text: Bone marrow is examined under light microscopy, as well as flow cytometry, to diagnose the presence of leukemia, to differentiate AML from other types of leukemia (e.g. acute lymphoblastic leukemia), and to provide information about how mature or immature the affected cells are that can assist in classifying the subtype of disease. A sample of marrow or blood is typically also tested for chromosomal abnormalities by routine cytogenetics or fluorescent "in situ" hybridization. Genetic studies may also be performed to look for specific mutations in genes such as "FLT3", nucleophosmin, and "KIT", which may influence the outcome of the disease.


title: Acute myeloid leukemia

text: Cytochemical stains on blood and bone marrow smears are helpful in the distinction of AML from ALL, and in subclassification of AML. The combination of a myeloperoxidase or Sudan black stain and a nonspecific esterase stain will provide the desired information in most cases. The myeloperoxidase or Sudan black reactions are most useful in establishing the identity of AML and distinguishing it from ALL. The nonspecific esterase stain is used to identify a monocytic component in AMLs and to distinguish a poorly differentiated monoblastic leukemia from ALL.


title: Acute myeloid leukemia

text: The standard classification scheme for AML is the World Health Organization (WHO) system. According to the WHO criteria, the diagnosis of AML is established by demonstrating involvement of more than 20% of the blood and/or bone marrow by leukemic myeloblasts, except in three forms of acute myeloid leukemia with recurrent genetic abnormalities: t(8;21), inv(16) or t(16;16), and acute promyelocytic leukemia with PML-RARA, in which the presence of the genetic abnormality is diagnostic irrespective of blast percent. Myeloid sarcoma is also considered a subtype of AML independently of the blast count. The older French-American-British (FAB) classification, which is no longer widely used, is a bit more stringent, requiring a blast percentage of at least 30% in bone marrow or peripheral blood for the diagnosis of AML.


title: Acute myeloid leukemia

text: Because acute promyelocytic leukemia has the highest curability and requires a unique form of treatment, it is important to quickly establish or exclude the diagnosis of this subtype of leukemia. Fluorescent "in situ" hybridization performed on blood or bone marrow is often used for this purpose, as it readily identifies the chromosomal translocation [t(15;17)(q22;q12);] that characterizes APL. There is also a need to molecularly detect the presence of PML/RARA fusion protein, which is an oncogenic product of that translocation.


title: Acute myeloid leukemia

text: The WHO classification of AML attempts to be more clinically useful and to produce more meaningful prognostic information than the FAB criteria. Each of the WHO categories contains numerous descriptive subcategories of interest to the hematopathologist and oncologist; however, most of the clinically significant information in the WHO schema is communicated via categorization into one of the subtypes listed below.


title: Acute myeloid leukemia

text: The revised fourth edition of the "WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues" was released in 2016. This classification, which is based on a combination of genetic and immunophenotypic markers and morphology, defines the subtypes of AML and related neoplasms as: In 2022 a new classification has been published.


title: Acute myeloid leukemia

text: Acute leukemias of ambiguous lineage (also known as mixed phenotype or biphenotypic acute leukemia) occur when the leukemic cells can not be classified as either myeloid or lymphoid cells, or where both types of cells are present.


title: Acute myeloid leukemia

text: The French-American-British (FAB) classification system provides terminology that is still sometimes used, and it remains a valuable diagnostic tool in areas without access to genetic testing, this system has largely become obsolete in favor of the WHO classification, which correlates more strongly with treatment outcomes.


title: Acute myeloid leukemia

text: The FAB system divides AML into eight subtypes, M0 through to M7, based on the type of cell from which the leukemia developed and its degree of maturity. AML of types M0 to M2 may be called acute myeloblastic leukemia. Classification is done by examining the appearance of the malignant cells with light microscopy and/or by using cytogenetics to characterize any underlying chromosomal abnormalities. The subtypes have varying prognoses and responses to therapy.


title: Acute myeloid leukemia

text: Six FAB subtypes (M1 through to M6) were initially proposed in 1976, although later revisions added M7 in 1985 and M0 in 1987.


title: Acute myeloid leukemia

text: The morphologic subtypes of AML also include rare types not included in the FAB system, such as acute basophilic leukemia, which was proposed as a ninth subtype, M8, in 1999.


title: Acute myeloid leukemia

text: First-line treatment of AML consists primarily of chemotherapy, and is divided into two phases: induction and consolidation. The goal of induction therapy is to achieve a complete remission by reducing the number of leukemic cells to an undetectable level; the goal of consolidation therapy is to eliminate any residual undetectable disease and achieve a cure. Hematopoietic stem cell transplantation is usually considered if induction chemotherapy fails or after a person relapses, although transplantation is also sometimes used as front-line therapy for people with high-risk disease. Efforts to use tyrosine kinase inhibitors in AML continue.


title: Acute myeloid leukemia

text: The goal of the induction phase is to reach a complete remission. Complete remission does not mean the disease has been cured; rather, it signifies no disease can be detected with available diagnostic methods. All subtypes except acute promyelocytic leukemia are usually given induction chemotherapy with cytarabine and an anthracycline such as daunorubicin or idarubicin. This induction chemotherapy regimen is known as "7+3" (or "3+7"), because the cytarabine is given as a continuous IV infusion for seven consecutive days while the anthracycline is given for three consecutive days as an IV push. Response to this treatment varies with age, with people aged less than 60 years having better remission rates between 60% and 80%, while older people having lower remission rates between 33% and 60%. Because of the toxic effects of therapy and a greater chance of AML resistance to this induction therapy, different treatment, such as that in clinical trials might be offered to people 60–65 years or older.


title: Acute myeloid leukemia

text: Acute promyelocytic leukemia is treated with all-"trans"-retinoic acid (ATRA) and either arsenic trioxide (ATO) monotherapy or an anthracycline. A syndrome similar to disseminated intravascular coagulation can develop during the initial few days of treatment or at the time the leukemia is diagnosed, and treatment can be complicated by a "differentiation syndrome" characterised by fever, fluid overload and low oxygen levels. Acute promyelocytic leukemia is considered curable. There is insufficient evidence to determine if prescribing ATRA in addition to chemotherapy to adults who have other subtypes of acute myeloid leukaemia is helpful.


title: Acute myeloid leukemia

text: Even after complete remission is achieved, leukemic cells likely remain in numbers too small to be detected with current diagnostic techniques. If no consolidation therapy or further postremission is given, almost all people with AML will eventually relapse.


title: Acute myeloid leukemia

text: The specific type of postremission therapy is individualized based on a person's prognostic factors (see above) and general health. For good-prognosis leukemias (i.e. inv(16), t(8;21), and t(15;17)), people will typically undergo an additional three to five courses of intensive chemotherapy, known as consolidation chemotherapy. This generally involves cytarabine, with the doses administered being higher in younger patients, who are less likely to develop toxicity related to this treatment.


title: Acute myeloid leukemia

text: Stem cell transplantation from a donor, called allogenic stem cell transplantation, is usually pursued if the prognosis is not considered favourable, a person can tolerate a transplant and has a suitable donor. The basis of allogenic stem cell transplantation is on a "graft versus leukemia" effect whereby graft cells stimulate an immune response against leukemia cells. Unfortunately this is accompanied by immune responses against other host organs, called a graft versus host disease.


title: Acute myeloid leukemia

text: Support is necessary throughout treatment because of problems associated with AML and also arising from treatment. Blood transfusions, including of red blood cells and platelets, are necessary to maintain health levels, preventing complications of anemia (from low red blood cells) and bleeding (from low platelets). AML leads to an increased risk of infections, particularly drug-resistant strains of bacteria and fungi. Antibiotics and antifungals can be used both to treat and to prevent these infections, particularly quinolones.


title: Acute myeloid leukemia

text: Adding aerobic physical exercises to the standard of care may result in little to no difference in the mortality, in the quality of life and in the physical functioning. These exercises may result in a slight reduction in depression. Furthermore, aerobic physical exercises probably reduce fatigue.


title: Acute myeloid leukemia

text: Recent research into the role that epigenetic regulators play in hematopoietic malignancies has yielded new insights in the development of targeted epigenetic therapies as a supportive treatment for AML. The FDA has approved certain epigenetic modifying drugs like ivosidenib and enasidenib, which are used in patients that can no longer receive intensive induction chemotherapy; specifically, they are involved in the therapy of IDH1 and IDH2 mutations. Further research must be done to prove the efficacy of epigenetic treatments, but the development of new epigenetic therapies along with immunotherapies holds potential in the future treatment of AML.


title: Acute myeloid leukemia

text: AML is rare in pregnancy, affecting about 1 in 75,000 to 100,000 pregnant women. It is diagnosed and treated similarly to AML in non pregnancy, with a recommendation that it is treated urgently. However, treatment has significant implications for the pregnancy. First trimester pregnancy is considered unlikely to be viable; pregnancy during weeks 24 – 36 requires consideration of the benefits of chemotherapy to the mother against the risks to the foetus; and there is a recommendation to consider delaying chemotherapy in very late pregnancy (> 36 weeks). Some elements of supportive care, such as which antibiotics to prevent or treat infections, also change in pregnancy.


title: Acute myeloid leukemia

text: Multiple factors influence prognosis in AML, including the presence of specific mutations, and a person with AML's age. In the United States between 2011 and 2016, the median survival of a person with AML was 8.5 months, with the 5 year survival being 24%. This declines with age, with the poorer prognosis being associated with an age greater than 65 years, and the poorest prognosis seen in those aged 75–84.


title: Acute myeloid leukemia

text: As of 2001, cure rates in clinical trials have ranged from 20 to 45%; although clinical trials often include only younger people and those able to tolerate aggressive therapies. The overall cure rate for all people with AML (including the elderly and those unable to tolerate aggressive therapy) is likely lower. Cure rates for APL can be as high as 98%.


title: Acute myeloid leukemia

text: Secondary AML has a worse prognosis, as does treatment-related AML arising after chemotherapy for another previous malignancy. Both of these entities are associated with a high rate of unfavorable genetic mutations.


title: Acute myeloid leukemia

text: Different genetic mutations are associated with a difference in outcomes. Certain cytogenetic abnormalities are associated with very good outcomes (for example, the (15;17) translocation in APL). About half of people with AML have "normal" cytogenetics; they fall into an intermediate risk group. A number of other cytogenetic abnormalities are known to associate with a poor prognosis and a high risk of relapse after treatment.


title: Acute myeloid leukemia

text: A large number of molecular alterations are under study for their prognostic impact in AML. However, only "FLT3-ITD", "NPM1", "CEBPA" and "c-KIT" are currently included in validated international risk stratification schema. These are expected to increase rapidly in the near future. "FLT3" internal tandem duplications (ITDs) have been shown to confer a poorer prognosis in AML with normal cytogenetics. Several FLT3 inhibitors have undergone clinical trials, with mixed results. Two other mutations – "NPM1" and biallelic "CEBPA" are associated with improved outcomes, especially in people with normal cytogenetics and are used in current risk stratification algorithms.


title: Acute myeloid leukemia

text: Researchers are investigating the clinical significance of "c-KIT" mutations in AML. These are prevalent, and potentially clinically relevant because of the availability of tyrosine kinase inhibitors, such as imatinib and sunitinib that can block the activity of "c-KIT" pharmacologically. It is expected that additional markers (e.g., "RUNX1", "ASXL1", and "TP53") that have consistently been associated with an inferior outcome will soon be included in these recommendations. The prognostic importance of other mutated genes (e.g., "DNMT3A", "IDH1", "IDH2") is less clear.


title: Acute myeloid leukemia

text: Elevated lactate dehydrogenase level were also associated with poorer outcomes. Use of tobacco is associated with a person having a poorer prognosis, and people who are married and live together have a better prognosis. People who are treated at place with a higher volume of AML have a better prognosis than those who are treated at those in the lowest quartile. As with most forms of cancer, performance status (i.e. the general physical condition and activity level of the person) plays a major role in prognosis as well.


title: Acute myeloid leukemia

text: AML is a relatively rare cancer. There were 19,950 new cases in the United States in 2016. In 2018, AML accounted for 1.2% of all cancer deaths in the United States.


title: Acute myeloid leukemia

text: The incidence of AML increases with age and varies between countries. The median age when AML is diagnosed ranges between 63 and 71 years in the UK, Canada, Australia and Sweden, compared with 40 to 45 years in India, Brazil and Algeria.


title: Acute myeloid leukemia

text: AML accounts for about 90% of all acute leukemias in adults, but is rare in children. The rate of therapy-related AML (AML caused by previous chemotherapy) is expected to rise with an increase in the use of chemotherapy, an ageing population and more patients surviving their initial chemotherapy treatment; therapy-related disease accounts for just under 10% of all cases of AML. AML is slightly more common in men, with a male-to-female ratio of 1.3:1 to 1.4:1. Incidence is also seen to differ by ethnicity, with caucasians having higher recorded incidences and the lowest recorded incidences being in Pacific Islanders and native Alaksans.


title: Acute myeloid leukemia

text: In the UK, AML accounts for 31% of all leukemia cases, and around 3,100 people were diagnosed with the disease each year in 2016–2018.


title: Acute myeloid leukemia

text: The first published description of a case of leukemia in medical literature dates to 1827 when French physician Alfred-Armand-Louis-Marie Velpeau described a 63-year-old florist who developed an illness characterized by fever, weakness, urinary stones, and substantial enlargement of the liver and spleen. Velpeau noted the blood of this person had a consistency "like gruel", and speculated the appearance of the blood was due to white corpuscles. In 1845, a series of people who died with enlarged spleens and changes in the "colors and consistencies of their blood" was reported by the Edinburgh-based pathologist J.H. Bennett; he used the term "leucocythemia" to describe this pathological condition.


title: Acute myeloid leukemia

text: The term "leukemia" was coined by Rudolf Virchow, the renowned German pathologist, in 1856. As a pioneer in the use of the light microscope in pathology, Virchow was the first to describe the abnormal excess of white blood cells in people with the clinical syndrome described by Velpeau and Bennett. As Virchow was uncertain of the etiology of the white blood cell excess, he used the purely descriptive term "leukemia" (Greek: "white blood") to refer to the condition.


title: Acute myeloid leukemia

text: Further advances in the understanding of AML occurred rapidly with the development of new technology. In 1877, Paul Ehrlich developed a technique of staining blood films which allowed him to describe in detail normal and abnormal white blood cells. Wilhelm Ebstein introduced the term "acute leukemia" in 1889 to differentiate rapidly progressive and fatal leukemias from the more indolent chronic leukemias. The term "myeloid" was coined by Franz Ernst Christian Neumann in 1869, as he was the first to recognize white blood cells were made in the bone marrow (Greek: , "", ) as opposed to the spleen. The technique of bone marrow examination to diagnose leukemia was first described in 1879 by Mosler. Finally, in 1900, the myeloblast, which is the malignant cell in AML, was characterized by Otto Naegeli, who divided the leukemias into myeloid and lymphocytic.


title: Acute myeloid leukemia

text: In 2008, AML became the first cancer genome to be fully sequenced. DNA extracted from leukemic cells were compared to unaffected skin. The leukemic cells contained acquired mutations in several genes that had not previously been associated with the disease.


title: Fructose

text: Fructose, or fruit sugar, is a ketonic simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed by the gut directly into the blood of the portal vein during digestion. The liver then converts both fructose and galactose into glucose, so that dissolved glucose, known as blood sugar, is the only monosaccharide present in circulating blood.


title: Fructose

text: Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847. The name "fructose" was coined in 1857 by the English chemist William Allen Miller. Pure, dry fructose is a sweet, white, odorless, crystalline solid, and is the most water-soluble of all the sugars. Fructose is found in honey, tree and vine fruits, flowers, berries, and most root vegetables.


title: Fructose

text: Commercially, fructose is derived from sugar cane, sugar beets, and maize. High-fructose corn syrup is a mixture of glucose and fructose as monosaccharides. Sucrose is a compound with one molecule of glucose covalently linked to one molecule of fructose. All forms of fructose, including those found in fruits and juices, are commonly added to foods and drinks for palatability and taste enhancement, and for browning of some foods, such as baked goods. About 240,000 tonnes of crystalline fructose are produced annually.


title: Fructose

text: Excessive consumption of sugars, including fructose, (especially from sugar-sweetened beverages) may contribute to insulin resistance, obesity, elevated LDL cholesterol and triglycerides, leading to metabolic syndrome. The European Food Safety Authority stated that fructose may be preferable over sucrose and glucose in sugar-sweetened foods and beverages because of its lower effect on postprandial blood sugar levels, while also noting the potential downside that "high intakes of fructose may lead to metabolic complications such as dyslipidaemia, insulin resistance, and increased visceral adiposity". The UK's Scientific Advisory Committee on Nutrition in 2015 disputed the claims of fructose causing metabolic disorders, stating that "there is insufficient evidence to demonstrate that fructose intake, at levels consumed in the normal UK diet, leads to adverse health outcomes independent of any effects related to its presence as a component of total and free sugars."


title: Fructose

text: The word "fructose" was coined in 1857 from the Latin for "fructus" (fruit) and the generic chemical suffix for sugars, "-ose". It is also called fruit sugar and levulose or laevulose.


title: Fructose

text: Fructose is a 6-carbon polyhydroxyketone. Crystalline fructose adopts a cyclic six-membered structure, called β--fructopyranose, owing to the stability of its hemiketal and internal hydrogen-bonding. In solution, fructose exists as an equilibrium mixture of the tautomers β--fructopyranose, β--fructofuranose, α--fructofuranose, α--fructopyranose and "keto"--fructose (the non-cyclic form).


title: Fructose

text: The distribution of -fructose tautomers in solution is related to several variables, such as solvent and temperature. -Fructopyranose and -fructofuranose distributions in water have been identified multiple times as roughly 70% fructopyranose and 22% fructofuranose.


title: Fructose

text: Fructose may be anaerobically fermented by yeast or bacteria. Yeast enzymes convert sugar (sucrose, glucose, or fructose, but not lactose) to ethanol and carbon dioxide. Some of the carbon dioxide produced during fermentation will remain dissolved in water, where it will reach equilibrium with carbonic acid. The dissolved carbon dioxide and carbonic acid produce the carbonation in some fermented beverages, such as champagne.


title: Fructose

text: Fructose undergoes the Maillard reaction, non-enzymatic browning, with amino acids. Because fructose exists to a greater extent in the open-chain form than does glucose, the initial stages of the Maillard reaction occur more rapidly than with glucose. Therefore, fructose has potential to contribute to changes in food palatability, as well as other nutritional effects, such as excessive browning, volume and tenderness reduction during cake preparation, and formation of mutagenic compounds.


title: Fructose

text: Fructose readily dehydrates to give hydroxymethylfurfural ("HMF", ), which can be processed into liquid dimethylfuran ().


title: Fructose

text: This process, in the future, may become part of a low-cost, carbon-neutral system to produce replacements for petrol and diesel from plants.


title: Fructose

text: The primary reason that fructose is used commercially in foods and beverages, besides its low cost, is its high relative sweetness. It is the sweetest of all naturally occurring carbohydrates. The relative sweetness of fructose has been reported in the range of 1.2–1.8 times that of sucrose. However, it is the 6-membered ring form of fructose that is sweeter; the 5-membered ring form tastes about the same as usual table sugar. Warming fructose leads to formation of the 5-membered ring form. Therefore, the relative sweetness decreases with increasing temperature. However it has been observed that the absolute sweetness of fructose is identical at 5 °C as 50 °C and thus the relative sweetness to sucrose is not due to anomeric distribution but a decrease in the absolute sweetness of sucrose at higher temperatures.


title: Fructose

text: The sweetness of fructose is perceived earlier than that of sucrose or glucose, and the taste sensation reaches a peak (higher than that of sucrose), and diminishes more quickly than that of sucrose. Fructose can also enhance other flavors in the system.


title: Fructose

text: Fructose exhibits a sweetness synergy effect when used in combination with other sweeteners. The relative sweetness of fructose blended with sucrose, aspartame, or saccharin is perceived to be greater than the sweetness calculated from individual components.


title: Fructose

text: Fructose has higher water solubility than other sugars, as well as other sugar alcohols. Fructose is, therefore, difficult to crystallize from an aqueous solution. Sugar mixes containing fructose, such as candies, are softer than those containing other sugars because of the greater solubility of fructose.


title: Fructose

text: Fructose is quicker to absorb moisture and slower to release it to the environment than sucrose, glucose, or other nutritive sweeteners. Fructose is an excellent humectant and retains moisture for a long period of time even at low relative humidity (RH). Therefore, fructose can contribute a more palatable texture, and longer shelf life to the food products in which it is used.


title: Fructose

text: Fructose has a greater effect on freezing point depression than disaccharides or oligosaccharides, which may protect the integrity of cell walls of fruit by reducing ice crystal formation. However, this characteristic may be undesirable in soft-serve or hard-frozen dairy desserts.


title: Fructose

text: Fructose increases starch viscosity more rapidly and achieves a higher final viscosity than sucrose because fructose lowers the temperature required during gelatinizing of starch, causing a greater final viscosity.


title: Fructose

text: Although some artificial sweeteners are not suitable for home-baking, many traditional recipes use fructose.


title: Fructose

text: Natural sources of fructose include fruits, vegetables (including sugar cane), and honey. Fructose is often further concentrated from these sources. The highest dietary sources of fructose, besides pure crystalline fructose, are foods containing white sugar (sucrose), high-fructose corn syrup, agave nectar, honey, molasses, maple syrup, fruit and fruit juices, as these have the highest percentages of fructose (including fructose in sucrose) per serving compared to other common foods and ingredients. Fructose exists in foods either as a free monosaccharide or bound to glucose as sucrose, a disaccharide. Fructose, glucose, and sucrose may all be present in a food; however, different foods will have varying levels of each of these three sugars.


title: Fructose

text: The sugar contents of common fruits and vegetables are presented in Table 1. In general, in foods that contain free fructose, the ratio of fructose to glucose is approximately 1:1; that is, foods with fructose usually contain about an equal amount of free glucose. A value that is above 1 indicates a higher proportion of fructose to glucose, and below 1 a lower proportion. Some fruits have larger proportions of fructose to glucose compared to others. For example, apples and pears contain more than twice as much free fructose as glucose, while for apricots the proportion is less than half as much fructose as glucose.


title: Fructose

text: Apple and pear juices are of particular interest to pediatricians because the high concentrations of free fructose in these juices can cause diarrhea in children. The cells (enterocytes) that line children's small intestines have less affinity for fructose absorption than for glucose and sucrose. Unabsorbed fructose creates higher osmolarity in the small intestine, which draws water into the gastrointestinal tract, resulting in osmotic diarrhea. This phenomenon is discussed in greater detail in the Health Effects section.


title: Fructose

text: Table 1 also shows the amount of sucrose found in common fruits and vegetables. Sugarcane and sugar beet have a high concentration of sucrose, and are used for commercial preparation of pure sucrose. Extracted cane or beet juice is clarified, removing impurities; and concentrated by removing excess water. The end-product is 99.9%-pure sucrose. Sucrose-containing sugars include common white sugar and powdered sugar, as well as brown sugar.


title: Fructose

text: The fructose/glucose ratio is calculated by dividing the sum of free fructose plus half sucrose by the sum of free glucose plus half sucrose.


title: Fructose

text: Fructose is also found in the manufactured sweetener, high-fructose corn syrup (HFCS), which is produced by treating corn syrup with enzymes, converting glucose into fructose. The common designations for fructose content, HFCS-42 and HFCS-55, indicate the percentage of fructose present in HFCS. HFCS-55 is commonly used as a sweetener for soft drinks, whereas HFCS-42 is used to sweeten processed foods, breakfast cereals, bakery foods, and some soft drinks.


title: Fructose

text: Cane and beet sugars have been used as the major sweetener in food manufacturing for centuries. However, with the development of HFCS, a significant shift occurred in the type of sweetener consumption in certain countries, particularly the United States. Contrary to the popular belief, however, with the increase of HFCS consumption, the total fructose intake relative to the total glucose intake has not dramatically changed. Granulated sugar is 99.9%-pure sucrose, which means that it has equal ratio of fructose to glucose. The most commonly used forms of HFCS, HFCS-42, and HFCS-55, have a roughly equal ratio of fructose to glucose, with minor differences. HFCS has simply replaced sucrose as a sweetener. Therefore, despite the changes in the sweetener consumption, the ratio of glucose to fructose intake has remained relatively constant.


title: Fructose

text: Providing 368 kcal per 100 grams of dry powder (table), fructose has 95% the caloric value of sucrose by weight. Fructose powder is 100% carbohydrates and supplies no other nutrients in significant amount (table).


title: Fructose

text: Fructose exists in foods either as a monosaccharide (free fructose) or as a unit of a disaccharide (sucrose). Free fructose is absorbed directly by the intestine. When fructose is consumed in the form of sucrose, it is digested (broken down) and then absorbed as free fructose. As sucrose comes into contact with the membrane of the small intestine, the enzyme sucrase catalyzes the cleavage of sucrose to yield one glucose unit and one fructose unit, which are then each absorbed. After absorption, it enters the hepatic portal vein and is directed toward the liver.


title: Fructose

text: The mechanism of fructose absorption in the small intestine is not completely understood. Some evidence suggests active transport, because fructose uptake has been shown to occur against a concentration gradient. However, the majority of research supports the claim that fructose absorption occurs on the mucosal membrane via facilitated transport involving GLUT5 transport proteins. Since the concentration of fructose is higher in the lumen, fructose is able to flow down a concentration gradient into the enterocytes, assisted by transport proteins. Fructose may be transported out of the enterocyte across the basolateral membrane by either GLUT2 or GLUT5, although the GLUT2 transporter has a greater capacity for transporting fructose, and, therefore, the majority of fructose is transported out of the enterocyte through GLUT2.


title: Fructose

text: The absorption capacity for fructose in monosaccharide form ranges from less than 5 g to 50 g (per individual serving) and adapts with changes in dietary fructose intake. Studies show the greatest absorption rate occurs when glucose and fructose are administered in equal quantities. When fructose is ingested as part of the disaccharide sucrose, absorption capacity is much higher because fructose exists in a 1:1 ratio with glucose. It appears that the GLUT5 transfer rate may be saturated at low levels, and absorption is increased through joint absorption with glucose. One proposed mechanism for this phenomenon is a glucose-dependent cotransport of fructose.


title: Fructose

text: In addition, fructose transfer activity increases with dietary fructose intake. The presence of fructose in the lumen causes increased mRNA transcription of GLUT5, leading to increased transport proteins. High-fructose diets (>2.4 g/kg body wt) increase transport proteins within three days of intake.


title: Fructose

text: Several studies have measured the intestinal absorption of fructose using the hydrogen breath test. These studies indicate that fructose is not completely absorbed in the small intestine. When fructose is not absorbed in the small intestine, it is transported into the large intestine, where it is fermented by the colonic flora. Hydrogen is produced during the fermentation process and dissolves into the blood of the portal vein. This hydrogen is transported to the lungs, where it is exchanged across the lungs and is measurable by the hydrogen breath test. The colonic flora also produces carbon dioxide, short-chain fatty acids, organic acids, and trace gases in the presence of unabsorbed fructose. The presence of gases and organic acids in the large intestine causes gastrointestinal symptoms such as bloating, diarrhea, flatulence, and gastrointestinal pain. Exercise immediately after consumption can exacerbate these symptoms by decreasing transit time in the small intestine, resulting in a greater amount of fructose emptied into the large intestine.


title: Fructose

text: All three dietary monosaccharides are transported into the liver by the GLUT2 transporter. Fructose and galactose are phosphorylated in the liver by fructokinase (K= 0.5 mM) and galactokinase (K = 0.8 mM), respectively. By contrast, glucose tends to pass through the liver (K of hepatic glucokinase = 10 mM) and can be metabolised anywhere in the body. Uptake of fructose by the liver is not regulated by insulin. However, insulin is capable of increasing the abundance and functional activity of GLUT5, fructose transporter, in skeletal muscle cells.


title: Fructose

text: The initial catabolism of fructose is sometimes referred to as fructolysis, in analogy with glycolysis, the catabolism of glucose. In fructolysis, the enzyme fructokinase initially produces fructose 1-phosphate, which is split by aldolase B to produce the trioses dihydroxyacetone phosphate (DHAP) and glyceraldehyde. Unlike glycolysis, in fructolysis the triose glyceraldehyde lacks a phosphate group. A third enzyme, triokinase, is therefore required to phosphorylate glyceraldehyde, producing glyceraldehyde 3-phosphate. The resulting trioses are identical to those obtained in glycolysis and can enter the gluconeogenic pathway for glucose or glycogen synthesis, or be further catabolized through the lower glycolytic pathway to pyruvate.


title: Fructose

text: The first step in the metabolism of fructose is the phosphorylation of fructose to fructose 1-phosphate by fructokinase, thus trapping fructose for metabolism in the liver. Fructose 1-phosphate then undergoes hydrolysis by aldolase B to form DHAP and glyceraldehydes; DHAP can either be isomerized to glyceraldehyde 3-phosphate by triosephosphate isomerase or undergo reduction to glycerol 3-phosphate by glycerol 3-phosphate dehydrogenase. The glyceraldehyde produced may also be converted to glyceraldehyde 3-phosphate by glyceraldehyde kinase or further converted to glycerol 3-phosphate by glycerol 3-phosphate dehydrogenase. The metabolism of fructose at this point yields intermediates in the gluconeogenic pathway leading to glycogen synthesis as well as fatty acid and triglyceride synthesis.


title: Fructose

text: The resultant glyceraldehyde formed by aldolase B then undergoes phosphorylation to glyceraldehyde 3-phosphate. Increased concentrations of DHAP and glyceraldehyde 3-phosphate in the liver drive the gluconeogenic pathway toward glucose and subsequent glycogen synthesis. It appears that fructose is a better substrate for glycogen synthesis than glucose and that glycogen replenishment takes precedence over triglyceride formation. Once liver glycogen is replenished, the intermediates of fructose metabolism are primarily directed toward triglyceride synthesis.


title: Fructose

text: Carbons from dietary fructose are found in both the free fatty acid and glycerol moieties of plasma triglycerides. High fructose consumption can lead to excess pyruvate production, causing a buildup of Krebs cycle intermediates. Accumulated citrate can be transported from the mitochondria into the cytosol of hepatocytes, converted to acetyl CoA by citrate lyase and directed toward fatty acid synthesis. In addition, DHAP can be converted to glycerol 3-phosphate, providing the glycerol backbone for the triglyceride molecule. Triglycerides are incorporated into very-low-density lipoproteins (VLDL), which are released from the liver destined toward peripheral tissues for storage in both fat and muscle cells.


title: Fructose

text: In 2022, the European Food Safety Authority (EFSA) concluded there is research evidence that fructose and other added free sugars may be associated with increased risk of several chronic diseases: the risk is moderate for obesity and dyslipidemia (more than 50%), and low for non-alcoholic fatty liver disease, type 2 diabetes (from 15% to 50%) and hypertension. EFSA stated that "the intake of added and free sugars should be as low as possible in the context of a nutritionally adequate diet."


title: Fructose

text: When fructose is consumed as a sweetening agent in foods or beverages, it may be associated with increased risk of obesity, diabetes, and cardiovascular disorders that are part of metabolic syndrome.


title: Fructose

text: Fructose was found to increase triglycerides in type-2 but not type-1 diabetes and moderate use of it has previously been considered acceptable as a sweetener for diabetics, possibly because it does not trigger the production of insulin by pancreatic β cells. For a 50 gram reference amount, fructose has a glycemic index of 23, compared with 100 for glucose and 60 for sucrose. Fructose is also 73% sweeter than sucrose at room temperature, allowing diabetics to use less of it per serving. Fructose consumed before a meal may reduce the glycemic response of the meal. Fructose-sweetened food and beverage products cause less of a rise in blood glucose levels than do those manufactured with either sucrose or glucose.


title: Dororo

text: A 26-episode anime television series adaptation by Mushi Productions aired in 1969. The anime series bears the distinction of being the first entry in what is now known as the "World Masterpiece Theater" series ("Calpis Comic Theater" at the time). "Dororo" was also made into a live-action film in 2007. A 24-episode second anime television series adaptation by MAPPA and Tezuka Productions aired from January to June 2019.


title: Dororo

text: "Dororo" revolves around a "rōnin" named and young orphaned thief named during the Sengoku period. The rōnin was born malformed, limbless and without facial features or internal organs. This was the result of his birth father "daimyō" Kagemitsu Daigō forging a pact with 48 sealed demons so that he might rule the land and increase its wealth and prosperity. In return, he promised the demons anything that they wanted which belonged to him. This enabled them to roam free and commit atrocities along the countryside.


title: Dororo

text: After his mother Nui no Kata was forced to set him adrift on the river, lest he be killed by his father, the infant was subsequently found and raised by Jukai, a medicine man who used healing magic and alchemist methods to give the child prostheses crafted from the remains of children who had died in the war. The boy became nearly invincible against any mortal blow as a result of the prostheses and healing magic. Grafted into his left arm was a very special blade that a traveling storyteller presented to Jukai, believing it was fated to be within his possession given that ever since the boy had been discovered, the doctor had been visited by goblins. As revealed in a short tale about the blade's origin, the blade had been forged out of vengeance to kill goblins as well as other supernatural entities.


title: Dororo

text: After the sensei was forced to send him on his way because he was attracting demons, the young man learned from a ghostly voice of the curse that had been set upon him at birth and that by killing the demons responsible he could reclaim the stolen pieces of his body and thus regain his humanity. Across his travels, he earned the name among other names for his inhuman nature. On one such hunt of a demon, Hyakkimaru came across a young orphan thief named Dororo who thereafter travels by his side through the war-torn countryside. When Hyakkimaru met Dororo, he had already killed 15 demons.


title: Dororo

text: Throughout their journey, Hyakkimaru killed six more demons, bringing the total to 21. Along the way, Hyakkimaru learns that Dororo was hiding a big secret. Dororo's father, Bandit Hibukuro, hid money he saved up on his raids on Bone Cape to later be distributed to the people squeezed dry by the samurai. Itachi, a bandit who betrayed Hibukuro and sided with the authorities, crippled Hibukuro. Hibukuro escaped with limping legs, along with his wife and young child. Hibukuro dies trying to let his remaining family escape. Fearing that she, too, will die, Ojyui had prayed to Buddha and, with her blood, drew the map that will lead him to Bone Cape. Three days later, she froze to death.


title: Dororo

text: Itachi kidnapped Dororo and used the map on "his" back to lead them to Bone Cape. A mysterious boatman ferried them to the Cape but he had two demon sharks with him. One of the sharks ate half of Itachi's bandits while the other shark left with the boatman. However, Dororo and the remaining bandits managed to kill the shark. When the boatman and the second shark returned, Dororo was able to separate the boatman and the shark. Hyakkimaru arrived to stab the shark in one of its eyes, but It escaped. They held the boatman prisoner and then they landed on Bone Cape.


title: Dororo

text: The boatman told the thirsty bandits of a spring not too far from their camp, and they went to drink, leaving Itachi, Dororo, the boatman and Hyakkimaru. Dororo later found their corpses and blood leading to the half-blind shark. Hyakkimaru killed the shark and the boatman, then recovered his real voice. Itachi went to search for the money but only found a letter from Hibukuro saying that he hid it somewhere else. The Magistrate arrived under the pretense of getting rid of the bandits but actually came for the treasure. Hyakkimaru, Dororo, and Itachi kill them, but Itachi was left for dead. Hyakkimaru and Dororo continued on their journey.


title: Dororo

text: Sometime later Hyakkimaru learns that his father, Kagemitsu Daigo, was possessed by the 48 demons, and went to slay him. Things were going badly on the Daigo clan's land, and the citizens were forced to build a fort for him. The slaves were planning a rebellion, but one of the slaves told Kagemitsu of their plans, and he was prepared. His archers shot and killed many slaves and the remainder hid in a tunnel they had built under the fort.


title: Dororo

text: Hyakkimaru left Dororo and ran into the fort. Dororo joined the slaves in their ambush, but Kagemitsu Daigo's soldiers caught Dororo. To prove his loyalty, Kagemitsu told Hyakkimaru to kill Dororo. Hyakkimaru acted as if he was about to kill Dororo but turned around and threw his sword into the dark stabbing the physical manifestation of the 48 demons, however, some of them managed to escape. The slaves charged through the tunnel and attacked Kagemitsu's soldiers. Kagemitsu, weak because of the slain demons, escaped with his wife Nui.


title: Dororo

text: After he regained his eyes, Hyakkimaru figured out that Dororo is female, though Dororo rejects the notion and refers to himself as a boy despite Hyakkimaru's insistence to act more feminine. This is in part due to Dororo being raised as a boy by his parents in order to be tough. Hyakkimaru also wanted Dororo to fight with the farmers against those in power because Dororo's father was a farmer. Hyakkimaru gave his sword to Dororo, the one that he had desired throughout the series. Hyakkimaru planned to continue his journey alone, agreeing to meet Dororo again when Hyakkimaru's body was whole. They parted with Dororo crying at the doors. It was not until 20 years later that the last of the 48 demons was slain, and he reunited with the full-grown Dororo.


title: Dororo

text: "Dororo" was first serialized in "Weekly Shōnen Sunday" between August 27, 1967, and July 22, 1968, before being cancelled. Parallel to the anime broadcast, the manga was then moved and concluded in Akita Shoten's "Bōken Ō" magazine from May to October 1969. Akita Shoten published the manga in four "tankōbon" volumes between August 12, 1971, and May 20, 1972. As part of its Osamu Tezuka Manga Complete Works edition, Kodansha compiled the manga into four volumes published between March 12 and June 12, 1981. Akita Shoten republished the manga in a three-volume deluxe edition between August 23 and October 18, 1990, and a new three-volume "bunkobon" edition under its Akita Bunko imprint on March 28, 1994. On November 11, 2009, Kodansha published the series in a two-volume edition.


title: Dororo

text: In 2008, Vertical Inc. released an English translation of "Dororo" in three volumes, published between April 29 and August 26. In 2009, it won the Eisner Award in the "Best U.S. Edition of International Material—Japan" division. In 2012, Vertical republished the manga in a single volume edition on March 20.


title: Dororo

text: A remake manga illustrated by Satoshi Shiki, titled , started in Akita Shoten's "Champion Red" on October 19, 2018. In May 2021, it was announced that the series entered its last arc. The first "tankōbon" volume was published on April 19, 2019. As of February 18, 2022, six volumes have been released. In North America, the manga has been licensed by Seven Seas Entertainment, and the first volume was released on June 9, 2020.


title: Dororo

text: A novel written by Masaki Tsuji and illustrated by Hideki Kitano was published by Asahi Sonorama in September 1978; it was later reprinted in January 2007. A three-volume series, written by Jinzō Toriumi, were published by in 2001; was released in July; was released in September; and was released in November. A two-volume novelization of the live-action film, written by , was released by The Asahi Shimbun on December 7, 2006.


title: Dororo

text: The first anime series was broadcast between April and September 1969. Unlike the manga, the anime version has a conclusive ending. In 2008, Anime Sols began a crowd-funding project for official streaming of the show. Funding for the first half of the show reached its goal, and the funding continued for the second half. However, Anime Sols folded, and Discotek Media picked up the project and released it on DVD in 2016, including the show's color pilot in the set.


title: Dororo

text: A 24-episode second anime television series adaptation by MAPPA and Tezuka Productions was announced in March 2018. The series aired from January 7 to June 24, 2019 through Amazon. The anime aired on Tokyo MX, BS11, and Jidaigeki Senmon Channel. Kazuhiro Furuhashi directs the series, with Yasuko Kobayashi handling series composition, Satoshi Iwataki handling character designs, and Yoshihiro Ike composing the music. Twin Engine produces the series. The first opening theme is performed by Queen Bee, while the first ending theme is performed by Amazarashi. The second opening is performed by Asian Kung-Fu Generation and the second ending theme is performed by Eve. On March 31, 2021, it was announced Sentai Filmworks has licensed the anime for home video release and will produce an English dub for the series.


title: Dororo

text: Developer Sega made a "Dororo"-based video game for the PlayStation 2 console in 2004. It was released in the United States and Europe under the title "Blood Will Tell". The game's artwork was done by renowned manga artist Hiroaki Samura. "Dororo" was not very successful commercially or critically, scoring a 69% average at GameRankings.


title: Dororo

text: On November 2, 2012, a manga crossover one-shot was published featuring Dororo and "Dororon Enma-kun"'s Emma. In 2013, it was expanded into a full series, published till February 21, 2014 and collected in two volumes.


title: Dororo

text: From 2018 to 2020, a manga reinterpretation of "Dororo", illustrated by Atsushi Kaneko, set in a futuristic, apocalyptic world with the main characters gender-swapped, titled "Search and Destroy", was published by Micro Magazine's "TezuComi". Its chapters were collected in three volumes.


title: Unknown (2011 film)

text: Unknown is a 2011 action-thriller film directed by Jaume Collet-Serra and starring Liam Neeson, Diane Kruger, January Jones, Aidan Quinn, Bruno Ganz, and Frank Langella. The film, produced by Joel Silver, Leonard Goldberg and Andrew Rona, is based on the 2003 French novel by Didier Van Cauwelaert published in English as "Out of My Head" which was adapted as the film's screenplay by Oliver Butcher and Stephen Cornwell. The narrative centers around a professor who wakes up from a four-day long coma and sets out to prove his identity after no one recognizes him, including his own wife, and another man claims to be him.


title: Unknown (2011 film)

text: Released on 18 February 2011, the film received mixed reviews from critics and grossed $136 million against its $30 million budget.


title: Unknown (2011 film)

text: Martin Harris and his wife Liz arrive in Berlin for a biotechnology summit. At their hotel, Harris realizes he left his briefcase at the airport and takes a taxi to retrieve it. The taxi is involved in an accident and crashes into the Spree, knocking him unconscious. The driver rescues him but flees the scene. Harris regains consciousness at a hospital after being in a coma for four days.


title: Unknown (2011 film)

text: When Harris returns to the hotel, he discovers Liz with another man. Liz says this man is her husband and declares she does not know Harris. The police are called, and Harris attempts to prove his identity by calling a colleague named Rodney Cole, to no avail. He writes down his schedule for the next day from memory. When he visits the office of Professor Leo Bressler, whom he is scheduled to meet, "Dr. Harris" is already there. As Harris attempts to prove his identity, "Harris" provides identification and a family photo, both of which have his face. Overwhelmed by the identity crisis, Harris loses consciousness and awakens back at the hospital. A terrorist named Smith kills Harris's attending nurse, but Harris is able to escape from him.


title: Unknown (2011 film)

text: Harris seeks help from a private investigator and former Stasi agent Ernst Jürgen. Harris's only clues are his father's book on botany and Gina, the taxi driver, an undocumented Bosnian immigrant who has been working at a diner since the crash. While Harris persuades her to help him, Jürgen researches Harris and the biotechnology summit, discovering it is to be attended by Prince Shada of Saudi Arabia. The prince is funding a secret project headed by Bressler, and has survived numerous assassination attempts. Jürgen suspects that the identity theft might be related.


title: Unknown (2011 film)

text: Harris and Gina are attacked in her apartment by Smith and another terrorist, Jones; they escape after Gina kills Smith. Harris finds that Liz has written a series of numbers in his book, numbers that correspond to words found on specific pages. Using his schedule, Harris confronts Liz alone; she tells him that he left his briefcase at the airport. Meanwhile, Jürgen receives Cole at his office and reveals his findings of a secret terrorist group known as Section 15. Jürgen soon deduces that Cole is a former mercenary and member of the group. Knowing Cole is there to interrogate and kill him and with no way of escape, Jürgen commits suicide to protect Harris.


title: Unknown (2011 film)

text: After retrieving his briefcase, Harris parts ways with Gina. When she sees him kidnapped by Cole and Jones, she steals a taxi and follows them. When Harris awakes, Cole explains that "Martin Harris" is just a cover name created by Harris. His head injury caused him to believe the cover persona was real; when Liz notified Cole of the injury, "Harris" was activated as his replacement. Gina runs over Jones before he can kill Harris, then rams Cole's van off a ledge, killing him as well. After Harris finds a hidden compartment in his briefcase containing two Canadian passports, he remembers that he and Liz were in Berlin three months earlier to plant a bomb in Prince Shada's suite.


title: Unknown (2011 film)

text: Now aware of his own role in the assassination plot, Harris seeks to redeem himself by thwarting it. Hotel security immediately arrests Harris and Gina, but Harris proves his earlier visit to the hotel. After security is convinced of the bomb's presence, they evacuate the hotel.


title: Unknown (2011 film)

text: Harris realizes that Section 15's target is not Prince Shada, but Bressler, who has developed a genetically modified breed of corn capable of surviving harsh climates. Liz accesses Bressler's laptop and steals the data. With Bressler's death and the theft of his research, billions of dollars would fall into the wrong hands. Seeing that the assassination attempt has been foiled, Liz tries to disarm the bomb but fails and is killed when it explodes. Harris kills "Harris", the last remaining Section 15 terrorist, before he can murder Bressler. While Bressler announces that he is giving his project to the world for free, Harris and Gina—with new identities—board a train together.


title: Unknown (2011 film)

text: Many German actors were cast for the film. Bock had previously starred in "Inglourious Basterds" (which also starred Diane Kruger) and "The White Ribbon". Other cast includes Adnan Maral as a Turkish taxi driver and Petra Schmidt-Schaller as an immigration officer. Kruger herself is also German, despite playing a non-German character.


title: Unknown (2011 film)

text: Principal photography took place in early February 2010 in Berlin, Germany, and in the Studio Babelsberg film studios. The bridge the taxi plunges from is the Oberbaumbrücke. The Friedrichstraße was blocked for several nights for the shooting of a car chase. Some of the shooting was done in the Hotel Adlon. Locations include the Neue Nationalgalerie, Berlin Hauptbahnhof, Berlin Friedrichstraße station, Pariser Platz, Museum Island, the Oranienburger Straße in Berlin and the Leipzig/Halle Airport. According to Andrew Rona, the budget was $40 million. Producer Joel Silver's US company Dark Castle Entertainment contributed $30 million. German public film funds supported the production with €4.65 million (more than $6 million). The working title was "Unknown White Male".


title: Unknown (2011 film)

text: "Unknown" was screened out of competition at the 61st Berlin International Film Festival. It was released in the United States on 18 February 2011.


title: Unknown (2011 film)

text: On Rotten Tomatoes, a review aggregator, the film has an approval rating of 55% based on 200 reviews; the average rating is 5.81/10. The site's critical consensus reads, "Liam Neeson elevates the proceedings considerably, but "Unknown" is ultimately too derivative – and implausible – to take advantage of its intriguing premise." On Metacritic the film has an average weighted score of 56 out of 100, based on 38 critics, indicating "mixed or average reviews". Audiences polled by CinemaScore gave the film an average grade of "B+" on an A+ to F scale.


title: Unknown (2011 film)

text: Richard Roeper gave the film a B+ and wrote, "At times, "Unknown" stretches plausibility to the near breaking point, but it's so well paced and the performances are so strong and most of the questions are ultimately answered. This is a very solid thriller." Justin Chang of "Variety" called it "an emotionally and psychologically threadbare exercise".


title: Unknown (2011 film)

text: "Unknown" grossed $63.7 million in North America and $72.4 million in other territories for a worldwide total of $136.1 million.


title: Unknown (2011 film)

text: In June 2021, it was announced that a sequel television series based on the film is in development at TNT. The project will be produced by Dark Castle Entertainment where Sean Finegan will write the pilot, Karl Gajdusek and Speed Weed will serve as executive producers and show runners, Neeson also will serve as executive producer and Collet-Serra will direct the pilot and executive produce.


title: Centrifugal force

text: In Newtonian mechanics, the centrifugal force is an inertial force (also called a "fictitious" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It is directed away from an axis which is parallel to the axis of rotation and passing through the coordinate system's origin. If the axis of rotation passes through the coordinate system's origin, the centrifugal force is directed radially outwards from that axis. The magnitude of centrifugal force "F" on an object of mass "m" at the distance "r" from the origin of a frame of reference rotating with angular velocity is: formula_1


title: Centrifugal force

text: The concept of centrifugal force can be applied in rotating devices, such as centrifuges, centrifugal pumps, centrifugal governors, and centrifugal clutches, and in centrifugal railways, planetary orbits and banked curves, when they are analyzed in a rotating coordinate system.


title: Centrifugal force

text: Confusingly, the term has sometimes also been used for the reactive centrifugal force, a real inertial-frame-independent Newtonian force that exists as a reaction to a centripetal force.


title: Centrifugal force

text: Centrifugal force is an outward force apparent in a rotating reference frame. It does not exist when a system is described relative to an inertial frame of reference.


title: Centrifugal force

text: All measurements of position and velocity must be made relative to some frame of reference. For example, an analysis of the motion of an object in an airliner in flight could be made relative to the airliner, to the surface of the Earth, or even to the Sun. A reference frame that is at rest (or one that moves with no rotation and at constant velocity) relative to the "fixed stars" is generally taken to be an inertial frame. Any system can be analyzed in an inertial frame (and so with no centrifugal force). However, it is often more convenient to describe a rotating system by using a rotating frame—the calculations are simpler, and descriptions more intuitive. When this choice is made, fictitious forces, including the centrifugal force, arise.


title: Centrifugal force

text: In a reference frame rotating about an axis through its origin, all objects, regardless of their state of motion, appear to be under the influence of a radially (from the axis of rotation) outward force that is proportional to their mass, to the distance from the axis of rotation of the frame, and to the square of the angular velocity of the frame. This is the centrifugal force. As humans usually experience centrifugal force from within the rotating reference frame, e.g. on a merry-go-round or vehicle, this is much more well-known than centripetal force.


title: Centrifugal force

text: Motion relative to a rotating frame results in another fictitious force: the Coriolis force. If the rate of rotation of the frame changes, a third fictitious force (the Euler force) is required. These fictitious forces are necessary for the formulation of correct equations of motion in a rotating reference frame and allow Newton's laws to be used in their normal form in such a frame (with one exception: the fictitious forces do not obey Newton's third law: they have no equal and opposite counterparts). Newton's third law requires the counterparts to exist within the same frame of reference, hence centrifugal and centripetal force, which do not, are not action and reaction (as is sometimes erroneously contended).


title: Centrifugal force

text: A common experience that gives rise to the idea of a centrifugal force is encountered by passengers riding in a vehicle, such as a car, that is changing direction. If a car is traveling at a constant speed along a straight road, then a passenger inside is not accelerating and, according to Newton's second law of motion, the net force acting on them is therefore zero (all forces acting on them cancel each other out). If the car enters a curve that bends to the left, the passenger experiences an apparent force that seems to be pulling them towards the right. This is the fictitious centrifugal force. It is needed within the passengers' local frame of reference to explain their sudden tendency to start accelerating to the right relative to the car—a tendency which they must resist by applying a rightward force to the car (for instance, a frictional force against the seat) in order to remain in a fixed position inside. Since they push the seat toward the right, Newton's third law says that the seat pushes them towards the left. The centrifugal force must be included in the passenger's reference frame (in which the passenger remains at rest): it counteracts the leftward force applied to the passenger by the seat, and explains why this otherwise unbalanced force does not cause them to accelerate. However, it would be apparent to a stationary observer watching from an overpass above that the frictional force exerted on the passenger by the seat is not being balanced; it constitutes a net force to the left, causing the passenger to accelerate toward the inside of the curve, as they must in order to keep moving with the car rather than proceeding in a straight line as they otherwise would. Thus the "centrifugal force" they feel is the result of a "centrifugal tendency" caused by inertia. Similar effects are encountered in aeroplanes and roller coasters where the magnitude of the apparent force is often reported in "G's".


title: Centrifugal force

text: If a stone is whirled round on a string, in a horizontal plane, the only real force acting on the stone in the horizontal plane is applied by the string (gravity acts vertically). There is a net force on the stone in the horizontal plane which acts toward the center.


title: Centrifugal force

text: In an inertial frame of reference, were it not for this net force acting on the stone, the stone would travel in a straight line, according to Newton's first law of motion. In order to keep the stone moving in a circular path, a centripetal force, in this case provided by the string, must be continuously applied to the stone. As soon as it is removed (for example if the string breaks) the stone moves in a straight line, as viewed from above. In this inertial frame, the concept of centrifugal force is not required as all motion can be properly described using only real forces and Newton's laws of motion.


title: Centrifugal force

text: In a frame of reference rotating with the stone around the same axis as the stone, the stone is stationary. However, the force applied by the string is still acting on the stone. If one were to apply Newton's laws in their usual (inertial frame) form, one would conclude that the stone should accelerate in the direction of the net applied force—towards the axis of rotation—which it does not do. The centrifugal force and other fictitious forces must be included along with the real forces in order to apply Newton's laws of motion in the rotating frame.


title: Centrifugal force

text: The Earth constitutes a rotating reference frame because it rotates once every 23 hours and 56 minutes around its axis. Because the rotation is slow, the fictitious forces it produces are often small, and in everyday situations can generally be neglected. Even in calculations requiring high precision, the centrifugal force is generally not explicitly included, but rather lumped in with the gravitational force: the strength and direction of the local "gravity" at any point on the Earth's surface is actually a combination of gravitational and centrifugal forces. However, the fictitious forces can be of arbitrary size. For example, in an Earth-bound reference system, the fictitious force (the net of Coriolis and centrifugal forces) is enormous and is responsible for the Sun orbiting around the Earth (in the Earth-bound reference system). This is due to the large mass and velocity of the Sun (relative to the Earth).


title: Centrifugal force

text: If an object is weighed with a simple spring balance at one of the Earth's poles, there are two forces acting on the object: the Earth's gravity, which acts in a downward direction, and the equal and opposite restoring force in the spring, acting upward. Since the object is stationary and not accelerating, there is no net force acting on the object and the force from the spring is equal in magnitude to the force of gravity on the object. In this case, the balance shows the value of the force of gravity on the object.


title: Centrifugal force

text: When the same object is weighed on the equator, the same two real forces act upon the object. However, the object is moving in a circular path as the Earth rotates and therefore experiencing a centripetal acceleration. When considered in an inertial frame (that is to say, one that is not rotating with the Earth), the non-zero acceleration means that force of gravity will not balance with the force from the spring. In order to have a net centripetal force, the magnitude of the restoring force of the spring must be less than the magnitude of force of gravity. Less restoring force in the spring is reflected on the scale as less weight — about 0.3% less at the equator than at the poles. In the Earth reference frame (in which the object being weighed is at rest), the object does not appear to be accelerating, however the two real forces, gravity and the force from the spring, are the same magnitude and do not balance. The centrifugal force must be included to make the sum of the forces be zero to match the apparent lack of acceleration.


title: Centrifugal force

text: For the following formalism, the rotating frame of reference is regarded as a special case of a non-inertial reference frame that is rotating relative to an inertial reference frame denoted the stationary frame.


title: Centrifugal force

text: In a rotating frame of reference, the time derivatives of any vector function of time—such as the velocity and acceleration vectors of an object—will differ from its time derivatives in the stationary frame. If are the components of with respect to unit vectors directed along the axes of the rotating frame (i.e. ), then the first time derivative of with respect to the rotating frame is, by definition, . If the absolute angular velocity of the rotating frame is then the derivative of with respect to the stationary frame is related to by the equation:


title: Centrifugal force

text: where formula_3 denotes the vector cross product. In other words, the rate of change of in the stationary frame is the sum of its apparent rate of change in the rotating frame and a rate of rotation formula_4 attributable to the motion of the rotating frame. The vector has magnitude equal to the rate of rotation and is directed along the axis of rotation according to the right-hand rule.


title: Centrifugal force

text: where is the vector sum of the physical forces applied to the particle and is the absolute acceleration (that is, acceleration in an inertial frame) of the particle, given by:


title: Centrifugal force

text: By applying the transformation above from the stationary to the rotating frame three times (twice to formula_7 and once to formula_8), the absolute acceleration of the particle can be written as:


title: Centrifugal force

text: The apparent acceleration in the rotating frame is formula_10. An observer unaware of the rotation would expect this to be zero in the absence of outside forces. However, Newton's laws of motion apply only in the inertial frame and describe dynamics in terms of the absolute acceleration formula_11. Therefore, the observer perceives the extra terms as contributions due to fictitious forces. These terms in the apparent acceleration are independent of mass; so it appears that each of these fictitious forces, like gravity, pulls on an object in proportion to its mass. When these forces are added, the equation of motion has the form:


title: Centrifugal force

text: From the perspective of the rotating frame, the additional force terms are experienced just like the real external forces and contribute to the apparent acceleration. The additional terms on the force side of the equation can be recognized as, reading from left to right, the Euler force formula_13, the Coriolis force formula_14, and the centrifugal force formula_15, respectively. Unlike the other two fictitious forces, the centrifugal force always points radially outward from the axis of rotation of the rotating frame, with magnitude , and unlike the Coriolis force in particular, it is independent of the motion of the particle in the rotating frame. As expected, for a non-rotating inertial frame of reference formula_16 the centrifugal force and all other fictitious forces disappear. Similarly, as the centrifugal force is proportional to the distance from object to the axis of rotation of the frame, the centrifugal force vanishes for objects that lie upon the axis.


title: Centrifugal force

text: Three scenarios were suggested by Newton to answer the question of whether the absolute rotation of a local frame can be detected; that is, if an observer can decide whether an observed object is rotating or if the observer is rotating.


title: Centrifugal force

text: In these scenarios, the effects attributed to centrifugal force are only observed in the local frame (the frame in which the object is stationary) if the object is undergoing absolute rotation relative to an inertial frame. By contrast, in an inertial frame, the observed effects arise as a consequence of the inertia and the known forces without the need to introduce a centrifugal force. Based on this argument, the privileged frame, wherein the laws of physics take on the simplest form, is a stationary frame in which no fictitious forces need to be invoked.


title: Centrifugal force

text: Within this view of physics, any other phenomenon that is usually attributed to centrifugal force can be used to identify absolute rotation. For example, the oblateness of a sphere of freely flowing material is often explained in terms of centrifugal force. The oblate spheroid shape reflects, following Clairaut's theorem, the balance between containment by gravitational attraction and dispersal by centrifugal force. That the Earth is itself an oblate spheroid, bulging at the equator where the radial distance and hence the centrifugal force is larger, is taken as one of the evidences for its absolute rotation.


title: Centrifugal force

text: The operations of numerous common rotating mechanical systems are most easily conceptualized in terms of centrifugal force. For example:


title: Centrifugal force

text: Nevertheless, all of these systems can also be described without requiring the concept of centrifugal force, in terms of motions and forces in a stationary frame, at the cost of taking somewhat more care in the consideration of forces and motions within the system.


title: Centrifugal force

text: The conception of centrifugal force has evolved since the time of Huygens, Newton, Leibniz, and Hooke who expressed early conceptions of it. Its modern conception as a fictitious force arising in a rotating reference frame evolved in the eighteenth and nineteenth centuries.


title: Centrifugal force

text: Centrifugal force has also played a role in debates in classical mechanics about detection of absolute motion. Newton suggested two arguments to answer the question of whether absolute rotation can be detected: the rotating bucket argument, and the rotating spheres argument. According to Newton, in each scenario the centrifugal force would be observed in the object's local frame (the frame where the object is stationary) only if the frame were rotating with respect to absolute space. Nearly two centuries later, Mach's principle was proposed where, instead of absolute rotation, the motion of the distant stars relative to the local inertial frame gives rise through some (hypothetical) physical law to the centrifugal force and other inertia effects. Today's view is based upon the idea of an inertial frame of reference, which privileges observers for which the laws of physics take on their simplest form, and in particular, frames that do not use centrifugal forces in their equations of motion in order to describe motions correctly.


title: Centrifugal force

text: The analogy between centrifugal force (sometimes used to create artificial gravity) and gravitational forces led to the equivalence principle of general relativity.


title: Centrifugal force

text: While the majority of the scientific literature uses the term "centrifugal force" to refer to the particular fictitious force that arises in rotating frames, there are a few limited instances in the literature of the term applied to other distinct physical concepts. One of these instances occurs in Lagrangian mechanics. Lagrangian mechanics formulates mechanics in terms of generalized coordinates {"q"}, which can be as simple as the usual polar coordinates formula_17 or a much more extensive list of variables. Within this formulation the motion is described in terms of "generalized forces", using in place of Newton's laws the Euler–Lagrange equations. Among the generalized forces, those involving the square of the time derivatives {(d"q"  ⁄ d"t" )} are sometimes called centrifugal forces. In the case of motion in a central potential the Lagrangian centrifugal force has the same form as the fictitious centrifugal force derived in a co-rotating frame. However, the Lagrangian use of "centrifugal force" in other, more general cases has only a limited connection to the Newtonian definition.


title: Centrifugal force

text: In another instance the term refers to the reaction force to a centripetal force, or reactive centrifugal force. A body undergoing curved motion, such as circular motion, is accelerating toward a center at any particular point in time. This centripetal acceleration is provided by a centripetal force, which is exerted on the body in curved motion by some other body. In accordance with Newton's third law of motion, the body in curved motion exerts an equal and opposite force on the other body. This reactive force is exerted "by" the body in curved motion "on" the other body that provides the centripetal force and its direction is from that other body toward the body in curved motion.


title: Centrifugal force

text: This reaction force is sometimes described as a "centrifugal inertial reaction", that is, a force that is centrifugally directed, which is a reactive force equal and opposite to the centripetal force that is curving the path of the mass.


title: Centrifugal force

text: The concept of the reactive centrifugal force is sometimes used in mechanics and engineering. It is sometimes referred to as just "centrifugal force" rather than as "reactive" centrifugal force although this usage is deprecated in elementary mechanics.


title: PAL

text: Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 frames) per second, and associated with CCIR analogue broadcast television systems B, D, G, H, I or K. The articles on analog broadcast television systems further describe frame rates, image resolution, and audio modulation.


title: PAL

text: PAL video is composite video because luminance (luma, monochrome image) and chrominance (chroma, colour applied to the monochrome image) are transmitted together as one signal.


title: PAL

text: A latter evolution of the standard, PALplus, added support for widescreen broadcasts with no loss of vertical resolution, while retaining compatibility with existing sets.


title: PAL

text: Almost all of the countries using PAL are currently in the process of conversion, or have already converted transmission standards to DVB, ISDB or DTMB.


title: PAL

text: Due to the introduction of digital sources (ex: DVD-Video) the name "PAL" might be used to refer to digital formats, even though they use completely different colour encoding systems. For example, 576i (576 interlaced lines) digital video with colour encoded as YCbCr, intended to be backward compatible and easily displayed on legacy PAL devices, is usually mentioned as "PAL" (ex: "PAL DVD"). Likewise, gaming consoles outputting a 50 Hz signal might be labeled as "PAL", as opposed to 60 Hz "NTSC" machines. These popular designations should not be confused with the analog colour system itself.


title: PAL

text: PAL was adopted by most European countries, by all African countries that had never been a Belgian or French colony, by Argentina, Brazil, Paraguay, Uruguay, and by most of Asia (including the Middle East) and the Pacific. Countries in those regions that did not adopt PAL were France, most ex-Soviet states, Japan, South Korea, Liberia, Myanmar, the Philippines, and Taiwan.


title: PAL

text: In the 1950s, the Western European countries began plans to introduce colour television, and were faced with the problem that the NTSC standard demonstrated several weaknesses, including colour tone shifting under poor transmission conditions, which became a major issue considering Europe's geographical and weather-related particularities. To overcome NTSC's shortcomings, alternative standards were devised, resulting in the development of the PAL and SECAM standards. The goal was to provide a colour TV standard for the European picture frequency of 50 fields per second (50 hertz), and finding a way to eliminate the problems with NTSC.


title: PAL

text: PAL was developed by Walter Bruch at Telefunken in Hanover, West Germany, with important input from . The format was patented by Telefunken in December 1962, citing Bruch as inventor, and unveiled to members of the European Broadcasting Union (EBU) on 3 January 1963. When asked why the system was named "PAL" and not "Bruch" the inventor answered that a "Bruch system" would probably not have sold very well ("Bruch" is the German word for "breakage").


title: PAL

text: The first broadcasts began in the United Kingdom in July 1967, followed by West Germany at the Berlin IFA on August 25. The BBC channel initially using the broadcast standard was BBC2, which had been the first UK TV service to introduce "625-lines" during 1964. The Netherlands and Switzerland started PAL broadcasts by 1968, with Austria following the next year.


title: PAL

text: "Telefunken PALcolour 708T" was the first PAL commercial TV set. It was followed by "Loewe-Farbfernseher S 920" and "F 900".


title: PAL

text: Telefunken was later bought by the French electronics manufacturer Thomson. Thomson also bought the "Compagnie Générale de Télévision" where Henri de France developed SECAM, the first European Standard for colour television. Thomson, now called Technicolour SA, also owns the RCA brand and licences it to other companies; Radio Corporation of America, the originator of that brand, created the NTSC colour TV standard before Thomson became involved.


title: PAL

text: The soviets developed two further systems, mixing concepts from PAL and SECAM, known as TRIPAL and NIIR, that never went beyond tests.


title: PAL

text: In the early 1970s, some Japanese set manufacturers developed decoding systems to avoid paying royalties to Telefunken. The Telefunken licence covered any decoding method that relied on the alternating subcarrier phase to reduce phase errors (described as "PAL-D" for "delay", and "PAL-N" for "new" or ""Chrominance Lock""; unrelated to the broadcast systems with similar designations). This excluded very basic PAL decoders that relied on the human eye to average out the odd/even line phase errors. This variations of the system is known as "PAL-S" (for "simple" or “Volks-PAL”), operating without a delay line and suffering from the “Hannover bars” effect, and for example was used on the "Kuba Porta Color CK211P" set. Another solution was to use a 1H analogue delay line to allow decoding of only the odd or even lines. For example, the chrominance on odd lines would be switched directly through to the decoder and also be stored in the delay line. Then, on even lines, the stored odd line would be decoded again. This method (known as 'gated NTSC') was adopted by Sony on their 1970s Trinitron sets ("KV-1300UB" to "KV-1330UB"), and came in two versions: "PAL-H" and "PAL-K" (averaging over multiple lines). It effectively converted PAL to NTSC, suffering from hue errors and other problems inherent in NTSC and required the addition of a manual hue control.


title: PAL

text: In 1993, an evolution of PAL aimed to improve and enhance format by allowing aspect ratio broadcasts, while remaining compatible with existing television receivers, was introduced. Named PALplus, it was defined by ITU recommendation BT.1197-1. It was developed at the University of Dortmund in Germany, in cooperation with German terrestrial broadcasters and European and Japanese manufacturers. Adoption was limited to European countries.


title: PAL

text: With the introduction of digital broadcasts and signal sources (ex: DVDs, game consoles), the term PAL was used imprecisely to refer to the 625-line/50 Hz television system in general, to differentiate from the 525-line/60 Hz system generally used with NTSC. For example, DVDs were labelled as PAL or NTSC (referring to the line count and frame rate) even though technically the discs carry neither PAL nor NTSC encoded signal. These devices would still have analog outputs (ex; composite video output), and would convert the digital signals (576i or 480i) to the analog standards to assure compatibility. CCIR 625/50 and EIA 525/60 are the proper names for these (line count and field rate) standards; PAL and NTSC on the other hand are methods of encoding colour information in the signal.


title: PAL

text: Most PAL systems encode the colour information using a variant of the Y'UV colour space. formula_1comprises the monochrome "luma" signal, with the three RGB colour channels mixed down onto two, formula_2 and formula_3.


title: PAL

text: Like NTSC, PAL uses a quadrature amplitude modulated subcarrier carrying the "chrominance" information added to the luma video signal to form a composite video baseband signal. The frequency of this subcarrier is 4.43361875 MHz for PAL 4.43, compared to 3.579545 MHz for NTSC 3.58. The SECAM system, on the other hand, uses a frequency modulation scheme on its two line alternate colour subcarriers 4.25000 and 4.40625 MHz.


title: PAL

text: The name "Phase Alternating Line" describes the way that the phase of part of the colour information on the video signal is reversed with each line, which automatically corrects phase errors in the transmission of the signal by cancelling them out, at the expense of vertical frame colour resolution. Lines where the colour phase is reversed compared to NTSC are often called PAL or phase-alternation lines, which justifies one of the expansions of the acronym, while the other lines are called NTSC lines. Early PAL receivers relied on the human eye to do that cancelling; however, this resulted in a comb-like effect known as Hanover bars on larger phase errors. Thus, most receivers now use a chrominance analogue delay line, which stores the received colour information on each line of display; an average of the colour information from the previous line and the current line is then used to drive the picture tube. The effect is that phase errors result in saturation changes, which are less objectionable than the equivalent hue changes of NTSC. A minor drawback is that the vertical colour resolution is poorer than the NTSC system's, but since the human eye also has a colour resolution that is much lower than its brightness resolution, this effect is not visible. In any case, NTSC, PAL, and SECAM all have chrominance bandwidth (horizontal colour detail) reduced greatly compared to the luma signal.


title: PAL

text: The 4.43361875 MHz frequency of the colour carrier is a result of 283.75 colour clock cycles per line plus a 25 Hz offset to avoid interferences. Since the line frequency (number of lines per second) is 15625 Hz (625 lines × 50 Hz ÷ 2), the colour carrier frequency calculates as follows: 4.43361875 MHz = 283.75 × 15625 Hz + 25 Hz.


title: PAL

text: The frequency 50 Hz is the optional refresh frequency of the monitor to be able to create an illusion of motion, while 625 lines means the vertical lines or resolution that the PAL system supports.


title: PAL

text: The original colour carrier is required by the colour decoder to recreate the colour difference signals. Since the carrier is not transmitted with the video information it has to be generated locally in the receiver. In order that the phase of this locally generated signal can match the transmitted information, a 10 cycle burst of colour subcarrier is added to the video signal shortly after the line sync pulse, but before the picture information, during the so-called back porch. This colour burst is not actually in phase with the original colour subcarrier, but leads it by 45 degrees on the odd lines and lags it by 45 degrees on the even lines. This swinging burst enables the colour decoder circuitry to distinguish the phase of the formula_4vector which reverses every line.


title: PAL

text: After 0.9 µs a colourburst of cycles is sent. Most rise/fall times are in range. Amplitude is 100% for white level, 30% for black, and 0% for sync.


title: PAL

text: The assumed display gamma is defined as 2.8. PAL-N uses YDbDr instead of YUV. The PAL-M system uses color primary and gamma values similar to NTSC.


title: PAL

text: Color is encoded using the YUV color space. Luma (formula_5) is derived from red, green, and blue (formula_6) gamma pre-corrected (formula_7) primary signals:


title: PAL

text: The PAL colour system is usually used with a video format that has 625 lines per frame (576 visible lines, the rest being used for other information such as sync data and captioning) and a refresh rate of 50 interlaced fields per second (compatible with 25 full frames per second), such systems being B, G, H, I, and N (see broadcast television systems for the technical details of each format).


title: PAL

text: This ensures video interoperability. However, as some of these standards (B/G/H, I and D/K) use different sound carriers (5.5 MHz, 6.0 MHz and 6.5 MHz respectively), it may result in a video image without audio when viewing a signal broadcast over the air or cable. Some countries in Eastern Europe which formerly used SECAM with systems D and K have switched to PAL while leaving other aspects of their video system the same, resulting in the different sound carrier. Instead, other European countries have changed completely from SECAM-D/K to PAL-B/G.


title: PAL

text: The PAL-N system has a different sound carrier, and also a different colour subcarrier, and decoding on incompatible PAL systems results in a black-and-white image without sound.


title: PAL

text: The PAL-M system has a different sound carrier and a different colour subcarrier, and does not use 625 lines or 50 frames/second. This would result in no video or audio at all when viewing a European signal.


title: PAL

text: The BBC tested their pre-war (but still broadcast until 1985) 405-line monochrome system (CCIR System A) with all three colour standards including PAL, before the decision was made to abandon 405 and transmit colour on 625/System I only.


title: PAL

text: Many countries have turned off analogue transmissions, so the following does not apply anymore, except for using devices which output RF signals, such as video recorders.


title: PAL

text: The majority of countries using or having used PAL have television standards with 625 lines and 50 fields per second. Differences concern the audio carrier frequency and channel bandwidths. The variants are:


title: PAL

text: Systems B and G are similar. System B specifies 7 MHz channel bandwidth, while System G specifies 8 MHz channel bandwidth. Australia used System B for VHF and UHF channels. Similarly, Systems D and K are similar except for the bands they use: System D is only used on VHF (except in mainland China), while System K is only used on UHF. Although System I is used on both bands, it has only been used on UHF in the United Kingdom.


title: PAL

text: The PAL-L (Phase Alternating Line with CCIR System L broadcast system) standard uses the same video system as PAL-B/G/H (625 lines, 50 Hz field rate, 15.625 kHz line rate), but with a larger 6 MHz video bandwidth rather than 5.5 MHz and moving the audio subcarrier to 6.5 MHz. An 8 MHz channel spacing is used for PAL-L, to maintain compatibility with System L channel spacings.


title: PAL

text: In Argentina, Paraguay and Uruguay the PAL-N variant is used (Phase Alternating Line with CCIR System N broadcast system). It employs the 625 line/50 field per second waveform of PAL-B/G, D/K, H, and I, but on a 6 MHz channel with a chrominance subcarrier frequency of 3.582056 MHz (917/4*H) very similar to NTSC (910/4*H). PAL-N uses the YDbDr colour space.


title: PAL

text: Extended features of the PAL specification, such as Teletext, are implemented quite differently in PAL-N. PAL-N supports a modified 608 closed captioning format that is designed to ease compatibility with NTSC originated NABTS content carried on line 18, and a modified teletext format that can occupy several lines.


title: PAL

text: In Brazil, PAL is used in conjunction with the 525 line, 59.94 field/s CCIR System M, using (very nearly) the NTSC colour subcarrier frequency. Exact colour subcarrier frequency of PAL-M is 3.575611 MHz, or 227.25 times System M's horizontal scan frequency. Almost all other countries using system M use NTSC.


title: PAL

text: The PAL colour system (either baseband or with any RF system, with the normal 4.43 MHz subcarrier unlike PAL-M) can also be applied to an NTSC-like 525-line (480i) picture to form what is often known as "PAL-60" (sometimes "PAL-60/525", "Quasi-PAL" or "Pseudo PAL"). PAL-M (a broadcast standard) however should not be confused with "PAL-60" (a video playback system—see below).


title: PAL

text: PAL television receivers manufactured in the 2000s can typically decode all of the PAL variants except, in some cases PAL-M and PAL-N. Many of receivers can also receive Eastern European and Middle Eastern SECAM, though rarely French-broadcast SECAM (because France used a quasi-unique positive video modulation, system L) unless they are manufactured for the French market. They will correctly display plain (non-broadcast) CVBS or S-video SECAM signals. Many can also accept baseband NTSC-M, such as from a VCR or game console, and RF modulated NTSC with a PAL standard audio subcarrier (i.e., from a modulator), though not usually broadcast NTSC (as its 4.5 MHz audio subcarrier is not supported). Many sets also support NTSC with a 4.43 MHz color subcarrier (see PAL 60 on the next section).


title: PAL

text: VHS tapes recorded from a PAL-N or a PAL-B/G, D/K, H, or I broadcast are indistinguishable because the downconverted subcarrier on the tape is the same. A VHS recorded off TV (or released) in Europe will play in colour on any PAL-N VCR and PAL-N TV in Argentina, Paraguay and Uruguay. Likewise, any tape recorded in Argentina, Paraguay or Uruguay off a PAL-N TV broadcast can be sent to anyone in European countries that use PAL (and Australia/New Zealand, etc.) and it will display in colour. This will also play back successfully in Russia and other SECAM countries, as the USSR mandated PAL compatibility in 1985—this has proved to be very convenient for video collectors.