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Porphyrin

Porphyrins are a group of heterocyclic macrocycle organic compounds, composed of four modified pyrrole subunits interconnected at their α carbon atoms via methine bridges. The parent of porphyrin is porphine, a rare chemical compound of theoretical interest. Substituted porphines are called porphyrins. With a total of 26 π-electrons, of which 18 π-electrons form a planar, continuous cycle, the porphyrin ring structure is described as aromatic. One result of the large conjugated system is that porphyrins absorb in the visible region of the electromagnetic spectrum, i.e. they are colored. The name "porphyrin" derives from the Greek word πορφύρα. Metal complexes derived from porphyrins occur naturally. One of the best-known families of porphyrin complexes is heme, the pigment in red blood cells, a cofactor of the protein hemoglobin. Representative porphyrins and derivatives Porphyrins are the conjugate acids of ligands that bind metals to form complexes; the metal ion has a charge of 2+ or 3+. A schematic equation for these syntheses is shown: H2porphyrin + 2+ → MLn−4 + 4 L + 2 H+, where M = metal ion and L = a ligandA porphyrin without a metal-ion in its cavity is a free base.

Some iron-containing porphyrins are called hemes. Heme-containing proteins, or hemoproteins, are found extensively in nature. Hemoglobin and myoglobin are two O2-binding proteins. Various cytochromes are hemoproteins. A benzoporphyrin is a porphyrin with a benzene ring fused to one of the pyrrole units. E.g. verteporfin is a benzoporphyrin derivative. Several other heterocycles are related to porphyrins; these include corrins, bacteriochlorophylls, corphins. Chlorins are more reduced, contain more hydrogen than porphyrins, i.e. one pyrrole has been converted to a pyrroline. This structure occurs in chlorophylls. Replacement of two of the four pyrrolic subunits with pyrrolinic subunits results in either a bacteriochlorin or an isobacteriochlorin, depending on the relative positions of the reduced rings; some porphyrin derivatives follow Hückel's rule. A geoporphyrin known as a petroporphyrin, is a porphyrin of geologic origin, they can occur in oil shale, coal, or sedimentary rocks. Abelsonite is the only geoporphyrin mineral, as it is rare for porphyrins to occur in isolation and form crystals.

In non-photosynthetic eukaryotes such as animals, insects and protozoa, as well as the α-proteobacteria group of bacteria, the committed step for porphyrin biosynthesis is the formation of δ-aminolevulinic acid by the reaction of the amino acid glycine with succinyl-CoA from the citric acid cycle. In plants, algae and archaea, it is produced from glutamic acid via glutamyl-tRNA and glutamate-1-semialdehyde; the enzymes involved in this pathway are glutamyl-tRNA synthetase, glutamyl-tRNA reductase, glutamate-1-semialdehyde 2,1-aminomutase. This pathway is known as the Beale pathway. Two molecules of dALA are combined by porphobilinogen synthase to give porphobilinogen, which contains a pyrrole ring. Four PBGs are combined through deamination into hydroxymethyl bilane, hydrolysed to form the circular tetrapyrrole uroporphyrinogen III; this molecule undergoes a number of further modifications. Intermediates are used in different species to form particular substances, but, in humans, the main end-product protoporphyrin IX is combined with iron to form heme.

Bile pigments are the breakdown products of heme. The following scheme summarizes the biosynthesis of porphyrins, with references by EC number and the OMIM database; the porphyria associated with the deficiency of each enzyme is shown: One of the most common syntheses for porphyrins is based on work by Paul Rothemund. His techniques underpin more modern synthesis such as those described by Longo; the synthesis of simple porphyrins such as meso-tetraphenylporphyrin is commonly done in university teaching labs. The Rothemund synthesis is a oxidation starting with pyrrole and an aldehyde. In solution-phase synthesis, acidic conditions are essential. A large amount of side-product is formed and is removed by recrystallization or chromatography. Green chemistry variants have been developed in which the reaction is performed with microwave irradiation using reactants adsorbed on acidic silica gel or at high temperature in the gas phase. In these cases, no additional acid is required; the main role of porphyrins is their support of aerobic life.

Porphyrins have been evaluated in the context of photodynamic therapy since they absorb light, converted to energy and heat in the illuminated areas. This technique has been applied in macular degeneration using verteporfin. PDT is considered a noninvasive cancer treatment, involving the interaction between light of a determined frequency, a photo-sensitizer, oxygen; this interaction produces the formation of a reactive oxygen species singlet oxygen, as well as superoxide anion, free hydroxyl radical, or hydrogen peroxide. These high reactive oxygen species react with susceptible cellular organic biomolecules such as. Bacteria have been shown to produce porphyrins endogenously as byproducts in heme biosynthesis, these can b

Leonardo Terigi

Leonardo Terigi is an Italian footballer who plays for Pistoiese. Born in Lucca, Terigi started his career at Ligurian club Genoa. In July 2010 Terigi was loaned to Serie B club Crotone with option to purchase. Terigi played 3 times for the first team in 2010–11 Serie B. In June 2011 Terigi was included in the transfer of Kevin Vinetot, which half of the registration rights of Terigi was valued €50,000. In January 2012 Terigi was signed by Carpi. In June 2012 the co-ownership deal of Vinetot and Terigi were renewed. However, on 30 August Terigi left for Carpi again. Terigi won promotion to Serie B with Carpi. In June 2013 Crotone still lack of incentive to buy Terigi outright, thus the co-ownership was renewed, he was sent to Grosseto of the third division in temporary deal on 22 August. On 20 June 2014 Genoa gave up the remain 50% registration rights of Terigi, as well as Crotone gave up the remain rights of Vinetot. On 11 July 2014 he was sold to Lega Pro club Alessandria. Since the summer of 2016 playing for Robur Siena.

On 30 January 2018, he joined Pistoiese. On 3 July 2018, he signed a contract extension until 2020. AIC profile Leonardo Terigi at Soccerway

Framing (construction)

Framing, in construction, is the fitting together of pieces to give a structure support and shape. Framing materials are wood, engineered wood, or structural steel; the alternative to framed construction is called mass wall construction, where horizontal layers of stacked materials such as log building, rammed earth, etc. are used without framing. Building framing is divided into two broad categories, heavy-frame construction if the vertical supports are few and heavy such as in timber framing, pole building framing, or steel framing. Light-frame construction using standardized dimensional lumber has become the dominant construction method in North America and Australia due to the economy of the method. Modern light-frame structures gain strength from rigid panels, but until carpenters employed various forms of diagonal bracing to stabilize walls. Diagonal bracing remains a vital interior part of many roof systems, in-wall wind braces are required by building codes in many municipalities or by individual state laws in the United States.

Special framed shear walls are becoming more common to help buildings meet the requirements of earthquake engineering and wind engineering. People fitted shaped wooden poles together as framework and began using joints to connect the timbers, a method today called traditional timber framing' or log framing. In the United States, timber framing was superseded by balloon framing beginning in the 1830s. Balloon framing makes use of many lightweight wall members called studs rather than fewer, heavier supports called posts; the studs in a balloon frame extend two stories from sill to plate. Platform framing is the standard wooden framing method today; the name comes from each floor level being framed as platform. Framed construction was used in Scandinavia before the 20th century because of the abundant availability of wood, an abundance of cheap labour, the superiority of the thermal insulation of logs. Wall framing in house construction includes the vertical and horizontal members of exterior walls and interior partitions, both of bearing walls and non-bearing walls.

These stick members, referred to as studs, wall plates and lintels, serve as a nailing base for all covering material and support the upper floor platforms, which provide the lateral strength along a wall. The platforms may be the boxed structure of a ceiling and roof, or the ceiling and floor joists of the story above. In the building trades, the technique is variously referred to as stick and frame and platform, or stick and box, as the sticks give the structure its vertical support, the box-shaped floor sections with joists contained within length-long post and lintels, support the weight of whatever is above, including the next wall up and the roof above the top story; the platform provides the lateral support against wind and holds the stick walls true and square. Any lower platform supports the weight of the platforms and walls above the level of its component headers and joists. Framing lumber is subject to regulated standards that require a grade-stamp, a moisture content not exceeding 19%.

There are three common methods of framing a house. Post and beam, now used predominantly in barn construction. Balloon framing using a technique suspending floors from the walls was common until the late 1940s, but since that time, platform framing has become the predominant form of house construction. Platform framing forms wall sections horizontally on the sub-floor prior to erection, easing positioning of studs and increasing accuracy while cutting the necessary manpower; the top and bottom plates are end-nailed to each stud with two nails at least 3.25 in in length. Studs are at least doubled at openings, the jack stud being cut to receive the lintels that are placed and end-nailed through the outer studs. Wall sheathing a plywood or other laminate, is applied to the framing prior to erection, thus eliminating the need to scaffold, again increasing speed and cutting manpower needs and expenses; some types of exterior sheathing, such as asphalt-impregnated fiberboard, oriented strand board and waferboard, will provide adequate bracing to resist lateral loads and keep the wall square.

Others, such as rigid glass-fiber, asphalt-coated fiberboard, polystyrene or polyurethane board, will not. In this latter case, the wall should be reinforced with a diagonal wood or metal bracing inset into the studs. In jurisdictions subject to strong wind storms local codes or state law will require both the diagonal wind braces and the stiff exterior sheathing regardless of the type and kind of outer weather resistant coverings. A multiple-stud post made up of at least three studs, or the equivalent, is used at exterior corners and intersections to secure a good tie b

Richard Llewellin

John Richard Allan Llewellin is a retired Anglican bishop in the Church of England. Llewellin was educated at Clifton College and Fitzwilliam College, Cambridge, he was made a deacon at Michaelmas 1964 and ordained priest the Michaelmas following — both times by Michael Gresford Jones, Bishop of St Albans, at St Albans Cathedral. After serving a second curacy at Johannesburg Cathedral, being expelled from South Africa by the apartheid Nationalist government of the day in 1971, he was successively the Vicar of Waltham Cross, the Rector of Harpenden and a canon of Truro Cathedral and ordained to the episcopate as the suffragan Bishop of St Germans, he was consecrated a bishop by Robert Runcie, Archbishop of Canterbury, on All Saints' Day 1985 at Westminster Abbey. He became the suffragan Bishop of Dover and was subsequently appointed Bishop at Lambeth and Chief of Staff to the Archbishop of Canterbury, a position he held until 2003. While serving as Bishop of Dover he was appointed an honorary fellow of Canterbury Christ Church University.

He served as Chairman of the Anglican Society for the Welfare of Animals from 2004 until 2013. Llewellin failed to launch an investigation into Jeremy Dowling. A 2018 case review found, “There is no doubt that there were a number of missed opportunities for the diocese of Truro to undertake its own investigations into the allegations made in 1972 against Jeremy Dowling.” Llewellin was one of four bishops in the diocese who failed to take action

Sheikh Zayed City

Sheikh Zayed City is a city in Giza Governorate in Egypt and part of the Greater Cairo urban area. It is named after Zayed bin Sultan Al Nahyan. In 2014, during the celebration of its 20th anniversary, the Minister of Housing, Mostafa Madbouly, said'the Urban Communities Authority’s budget had been expanded for the 2014/2015 fiscal year so that all plans may be implemented and completed'. A technology center opened that day in Sheikh Zayed City but residents complained about the lack of other facilities. Sheikh Zayed City is situated about 20 km from Lebanon Square in the Mohandiseen district of Giza, it is bordered to the north by the Cairo-Alexandria desert road, to the south by the 26 July Corridor, to the west by the neighboring 6th of October. The city forms part of the Giza Governorate, is divided into 17 residential districts, with four neighborhoods in each district. Sheikh Zayed City sits 226 meters above mean sea level. Köppen-Geiger climate classification system classifies its climate as hot desert.

Its climate is similar to Giza and Cairo, owing to its proximity to them. The American International School in Egypt West Campus is located in Sheikh Zayed City. Deutsche Schule Beverly Hills Kairo American Beverly Hills School English Beverly Hills School The Maharat Super Global School Elsheikh Zayed Secondary Schools For boys Elsheikh Zayed Secondary Schools For girls New Manor House School Ethos International School Greenland international school American international school The British School, CAIRO The Canadian International University Faculty of engineering Cairo University Faculty of commerce English Section Nile University National Training Academy Smart Village El-Sheikh Zayed — specialized hospital New Urban Communities Authority

Ksenia Polikarpova

Ksenia Olegovna Polikarpova is a Russian-born Israeli badminton player. In 2009, she won a bronze medal at the European Junior Championships in Italy, she won bronze medals at the European Mixed Team Badminton Championships in 2011, 2013, 2015 with Russian national badminton team. Polikarpova won a gold medal in 2017 Maccabiah Games. Girls' doubles The BWF Grand Prix has the BWF Grand Prix and Grand Prix Gold, it is a series of badminton tournaments sanctioned by the Badminton World Federation since 2007. Women's singles Women's doubles BWF Grand Prix Gold tournament BWF Grand Prix tournament Women's singles Women's doubles Mixed doubles BWF International Challenge tournament BWF International Series tournament BWF Future Series tournament Baku2015.com Ksenia Polikarpova at BWF.tournamentsoftware.com