4-2-1 engine exhaust systems

4-Carboxyphthalic anhydride

4-Bromoamphetamine

4-Acetoxy-MiPT

4-D Warriors is a shoot 'em up arcade game released by Sega / Coreland in 1985 .

4-Bromomethcathinone (4-BMC, Brephedrone) is a psychoactive drug and research chemical of the phenethylamine, amphetamine, and cathinone chemical classes. It acts as a serotonin and norepinephrine reuptake inhibitor, but acts more like an antidepressant than a stimulant. It is currently unclear whether the 4-halogenated cathinones share the selective serotonergic neurotoxicity of their corresponding amphetamines.

4-D

changed

4-Deoxypyridoxine

4-20 mA

oral, intranasal, intravenous, rectal,

Space-filling model of the 4-aminophenol molecule

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the 4-6-0+0-6-4 is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-6-0 ten-wheeler locomotives operating back to back, with the boiler and cab suspended between the two swivelling power units. Each power unit has two pairs of leading wheels in a leading bogie, followed by three coupled pairs of driving wheels and no trailing wheels.A similar wheel arrangement exists for Mallet type locomotives, but is referred to as 4-6-6-4. On a Mallet locomotive, only the front engine unit swivels while the rear unit is rigid in relation to the main frame.

4-Day Weekend

Bromofluorobenzene space filling re-edit.png

4-Chloromethcathinone (also known as 4-CMC and Clephedrone) is a stimulant drug of the cathinone class that has been sold online as a designer drug.

5-(Hydroxymethyl)-2,4-dimethylpyridin-3-ol

4-3 point

Skeletal formula of 4-cyano-4'-pentylbiphenyl

Purpald; AHMT; 1,2,4-Triazolidin-3-one, 4-amino-5-thioxo-, hydrazone ; 4H-1,2,4-Triazole-3-thiol, 4-amino-5-hydrazino-

4-64 armor

CCCCN2CCCC2

4-Caffeoyl-1, 5-quinide

4-Amino-2-trifluoromethylbenzonitrile

4-AcO-DET

4-D (3,5-methoxy-4-trideuteromethoxyphenethylamine) is a lesser-known recreational psychedelic drug. It is one of the few drugs that bears deuterium. It is a deuterated analog of mescaline. It may be prepared either as a sulfate salt or a hydrochloride salt. 4-D was first synthesized by Alexander Shulgin. In his book PiHKAL (Phenethylamines i Have Known And Loved), the dosage is listed as approximately 200–400 mg for the sulfate salt, and 178–356 mg for the hydrochloride salt. 4-D lasts for approximately 12 hours. It causes closed-eye visuals, mild open-eye visuals, color distortion, and mydriasis. Very little data exists about the pharmacological properties, metabolism, and toxicity of 4-D.

Folk Songs for Far Out Folk

Class B

Diagram of two small leading wheels, a single large driving wheel and two small trailing wheels

4-Chlorophenylisobutylamine (4-CAB, AEPCA), also known as 4-chloro-α-ethylphenethylamine, is an entactogen and stimulant drug of the phenethylamine class.

4-Cyano-4'-pentylbiphenyl is a commonly used nematic liquid crystal with the chemical formula C18H19N. It frequently goes by the common name 5CB. 5CB was first synthesized by George William Gray, Ken Harrison, and J.A. Nash at the University of Hull in 1972 and at the time it was the first member of the cyanobiphenyls. The liquid crystal was discovered after Gray's group received a grant from the UK Ministry of Defence to find a liquid crystal that had liquid crystal phases near room temperature with the specific intention of using them in liquid crystal displays. The molecule is about 20 Å long. The liquid crystal 5CB undergoes a phase transition from a crystalline state to a nematic state at 18 °C and it goes from a nematic to an isotropic state at 35 °C.

[3-[2-[Isopropyl(methyl)amino]ethyl]-1H-indol-4-yl] acetate

acetic acid

Under the Whyte notation for the classification of steam locomotives, a 4-8-8-2 is a locomotive with four leading wheels, two sets of eight driving wheels, and a two-wheel trailing truck.Other equivalent classifications are:UIC classification: 2DD1 (also known as German classification and Italian classification)French classification: 240+041Turkish classification: 46+45Swiss classification: 4/6+4/5The equivalent UIC classification is refined to (2'D)D1' for Mallet locomotives.A locomotive of that length must be an articulated locomotive; meaning all have a joint between the first and second groups of driving wheels.

Quinolin-4-amine

(4-Carboxyphenyl)chloromercury

4-Chloro-2-methylaniline

Premature wear

Diagram of two small leading wheels, eight large driving wheels in two foursomes, each foursome joined by coupling rods, and two small trailing wheels

4-A

4-Aminoquinoline is a form of aminoquinoline with the amino group at the 4-position of the quinoline.A variety of derivatives of 4-aminoquinoline are antimalarial agents useful in treating erythrocytic plasmodial infections. Examples include amodiaquine, chloroquine, and hydroxychloroquine.

chloromercury

4-Chlorophthalic anhydride

Structural formula of 4-aminoquinoline

4-Acetyloxy-N,N-diallyltryptamine (or 4-AcO-DALT) is a tryptamine derivative. It has been sold as a designer drug, but little other information is available. It was first officially identified in seized drug samples in 2012.

4-Aminoantipyrine

"Sleazy Bed Track"

4-Acetoxy-DET (4-Acetoxy-N,N-diethyltryptamine), also known as ethacetin, ethylacybin or 4-AcO-DET is a psychedelic tryptamine. It was first synthesized in 1958 by Albert Hofmann in the Sandoz lab.It is expected that the compound is quickly hydrolyzed into the free phenolic 4-HO-DET by serum esterases, but human studies concerning the metabolic fate of this drug are lacking.

4-Bromo-3,5-dimethoxyamphetamine is a lesser-known psychedelic drug and a substituted Amphetamine. It was first synthesized by Alexander Shulgin. In his book PiHKAL (Phenethylamines i Have Known And Loved), the dosage range is listed as 4–10 mg, and the duration listed as 8–12 hours. It produces analgesia, numbness and reduction of physical feeling. Very little data exists about its pharmacological properties, metabolism, and toxicity.

4-3 defense

NP class A

Vitamin Bx

4-Anisidine

p-Aminobenzoic acid

4-2-2 Eight-man Football Defense

CC=O

A 4-8-8-4 in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a locomotive with a four-wheel leading truck, two sets of eight driving wheels, and a four-wheel trailing truck.

acridin-4-amine

4-Amino-3-hydrazino-5-mercapto-1,2,4-triazole is an organic compound with the formula SC2N3H(NH2)(N2H3). The compound consists of a 1,2,4-triazole heterocycle with three functional groups: amine, thioamide, hydrazide. X-ray crystallography shows that this molecule is polar but with a C=S double bond. It is prepared by the reaction of hydrazine with thiourea:2 SC(NH2)2 + 3 N2H4 → SC2N3H(NH2)(N2H3) + 4 NH3 + H2SThe compound has been used as a reagent for the colorimetric detection of aldehydes.

C=black, H=white, O=red, N=blue

4-Aminoquinoline

4-Amino-5-hexenoic acid

4-Dehydroepiandrosterone

4-Ball billiards

4-Cresol dehydrogenase (hydroxylating)

Under the Whyte notation for the classification of steam locomotives, 4-2-4 represents the wheel arrangement of four leading wheels on two axles, two powered driving wheels on one axle, and four trailing wheels on two axles.

4-Bromo-2,5-dimethoxy-phenethylamine

4-Chloro-2,5-dimethoxyamphetamine

4-Chloro-o-toluidine

4-8a Rutland Gate

4-Ball (golf)

Better high speed performance

4-Benzylpiperidine is a drug and research chemical used in scientific studies. It acts as a monoamine releasing agent with 20- to 48-fold selectivity for releasing dopamine versus serotonin. It has a fast onset of action and a short duration. It also functions as a monoamine oxidase inhibitor (MAOI) with preference for MAO-A.

4-Cyano-3-trifluoromethyl-aniline

4-3-3 formation

4-Dimethylallyltryptophan N-methyltransferase

group_or_band

4-5-6 Trio

Santa Fe no. 3751 of 1927

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the 4-8-4+4-8-4 is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-8-4 locomotives operating back to back, with the boiler and cab suspended between the two engine units. Each engine unit has two pairs of leading wheels in a leading bogie, followed by four coupled pairs of driving wheels and two pairs of trailing wheels in a trailing bogie.

4-Dehydroepiandrosterone (4-DHEA) is a steroid that is an isomer of 5-dehydroepiandrosterone.4-DHEA has been prepared by laboratory synthesis.

Schedule I

Image:Baltimore and Ohio Duplex.jpg

4-6 duopyramid

4-Aminobenzoic acid (also known as para-aminobenzoic acid or PABA because the number 4 carbon in the benzene ring is also known as the para position) is an organic compound with the formula H2NC6H4CO2H. PABA is a white solid, although commercial samples can appear gray. It is slightly soluble in water. It consists of a benzene ring substituted with amino and a carboxyl groups. The compound occurs naturally.

4-Amino-3,5,6-trichloropicolinic acid

4-Bromo-2,5-dimethoxyphenethylamine

4-Coumaric acid

Vitamin B10

In Whyte notation, a 4-6-6-4 is a railroad steam locomotive that has four leading wheels followed by six coupled driving wheels, a second set of six driving wheels and four trailing wheels. 4-6-6-4's are commonly known as Challengers. Challengers were most common in the Union Pacific Railroad and the Clinchfield Railroad.This locomotive was impressive and widely used by the Union Pacific for passenger service but was mostly used for freight. Other equivalent classifications are:UIC classification: 2CC2 (also known as German classification and Italian classification)French classification: 230+032Turkish classification: 35+35Swiss classification: 3/5+3/5The UIC classification is refined to (2'C)C2' for Mallet locomotives.One such locomotive, Union Pacific 3985 is still operable, and it is currently the largest operable steam locomotive in the world. Another example, Union Pacific 3977 is on static display in North Platte, Nebraska. An expansion for the Union Pacific Challenger class was the Union Pacific Big Boy class, being a 4-8-8-4, instead of a 4-6-6-4.Though originally intended for freight service, many units could be found leading passenger consists as well. Railroads that used the Challenger type locomotive include:

4-8-2 Mountains

Australia

Fred Katz

SAR Class GF .jpg

*Superior Quality
*

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, a 4-6-2+2-6-4 is a Garratt or Union Garratt articulated locomotive using a pair of 4-6-2 engine units back to back, with the boiler and cab suspended between them. The 4-6-2 wheel arrangement of each engine unit has four leading wheels on two axles, usually in a leading bogie, six powered and coupled driving wheels on three axles, and two trailing wheels on one axle, usually in a trailing truck.

4-COT

Glenn Holland

4-Chloro-2,5-DMA

Beyer, Peacock and Company

none

4-Acetoxy-DIPT

Under the Whyte notation for the classification of steam locomotives, 4-4-4 represents the wheel arrangement of four leading wheels on two axles, four powered and coupled driving wheels on two axles, and four trailing wheels on two axles. In the United States, this arrangement was named the Reading type, since the Philadelphia and Reading Railroad was the first to use it.

4-6-2 locomotive

Ball-and-stick model of the PABA molecule

4-Chloronitrobenzene

4-2-1 engine exhaust systems for automobiles are designed to ease the flow of exhaust gases of combustion leaving an internal combustion engine, thereby achieving optimal power output. Conventional exhaust systems, which are outfitted as standard components by automakers, are typically of the 4-1 type.The system goes by the name "4-2-1" as a reference to the exhaust pipe layout for a 4-cylinder engine: four pipes (primary) come off the cylinder head, and merge into two pipes (secondary), which in turn finally link up to form one collector pipe. This collector then leads to the catalytic converter and muffler, before the exhaust gases finally leave the car through the tail pipe.

4-Chlorophthalic anhydride is a monochlorinated aromatic anhydride. It is an isomer of 3-chlorophthalic anhydride and a derivative of phthalic anhydride.

United States of America

4-Chloro-alpha-pyrrolidinovalerophenone (also known as 4-chloro-alpha-pyrrolidinopentiophenone, 4Cl-PVP, or 4C-PVP) is an emerging recreational designer drug of the pyrrolidinophenone class, similar in structure to alpha-pyrrolidinopentiophenone (α-PVP). The pharmacology and toxicity of this compound is unknown.

4-Chloroformylphthalic anhydride

UEJBEYOXRNGPEI-UHFFFAOYSA-N

4-20 ma

4-Aminoacridine is an aminoacridine.

4-Cyano-3-(trifluoromethyl)aniline

4-AcO-DiPT

CCNC
OOJXMFNDUXHDOV-UHFFFAOYSA-N

BTTWKVFKBPAFDK-LOVVWNRFSA-N

4-Chlorobenzoyl-CoA dehalogenase

4-Bromo-3,5-dimethoxyamphetamine

4-Androstenediol, also known as androst-4-ene-3β,17β-diol, is an androstenediol that is converted to testosterone. The conversion rate is about 15.76%, almost triple that of 4-androstenedione, due to utilization of a different enzymatic pathway. There is also some conversion into estrogen, since testosterone is the metabolic precursor of the estrogens.4-Androstenediol is closer to testosterone structurally than 5-androstenediol, and has androgenic effects, acting as a weak partial agonist of the androgen receptor. However, due to its lower intrinsic activity in comparison, in the presence of full agonists like testosterone or dihydrotestosterone (DHT), 4-androstenediol has antagonistic actions, behaving more like an antiandrogen.4-Androstenediol is very weakly estrogenic. It has approximately 0.5% and 0.6% of the affinity of estradiol at the ERα and ERβ, respectively.

4-Cyano-3-(trifluoromethyl)-aniline

4-5-6 Trio (subtitled Mood Jazz in Hi Fi) is an album by Fred Katz originally released on Decca in 1959.

4-Bromofluorobenzene is a halogenated aromatic organic compound with the formula C6H4BrF. It is a derivative of benzene, with a bromine atom bonded para to a fluorine atom. It has uses as a precursor to some pharmaceuticals, as an agrochemical intermediate, and in organic synthesis.

4-Chloroindole-3-acetic acid

4-Digits

4-Amino-3-hydrazino-5-mercapto-1,2,4-triazole

4-Androstenediol diacetate

4-Chlorophenylalanine

4-3 slide

NIGBFBTVONRYQN-UHFFFAOYSA-N

Front of locomotive at left

4-CGA

4-4-5 Calendar

John McNamara

4-20mA

In enzymology, a 4-coumarate-CoA ligase (EC 6.2.1.12) is an enzyme that catalyzes the chemical reactionATP + 4-coumarate + CoA ⇌ {\displaystyle \rightleftharpoons } AMP + diphosphate + 4-coumaroyl-CoAThe 3 substrates of this enzyme are ATP, 4-coumarate, and CoA, whereas its 3 products are AMP, diphosphate, and 4-coumaroyl-CoA.This enzyme belongs to the family of ligases, to be specific those forming carbon-sulfur bonds as acid-thiol ligases.

4-Bit

p-Aminobiphenyl

4-Bromo-2,5-dimethoxybenzylpiperazine

4-CAB

Parachlorophenoxyacetate

Locomotive 87 KUR, Karamoja.jpg

4-D (3,5-methoxy-4-trideuteromethoxyphenethylamine) is a lesser-known recreational psychedelic drug. It is one of the few drugs that bears deuterium. It is a deuterated analog of mescaline. It may be prepared either as a sulfate salt or a hydrochloride salt. 4-D was first synthesized by Alexander Shulgin. In his book PiHKAL (Phenethylamines i Have Known And Loved), the dosage is listed as approximately 200–400 mg for the sulfate salt, and 178–356 mg for the hydrochloride salt.

South African Railways

4-Aminophenol (or para-aminophenol or p-aminophenol) is the organic compound with the formula H2NC6H4OH. Typically available as a white powder, it was commonly used as a developer for black-and-white film, marketed under the name Rodinal.Reflecting its slightly hydrophilic character, the white powder is moderately soluble in alcohols and can be recrystallized from hot water. In the presence of a base, it oxidizes readily.

United Kingdom

In Whyte notation, a 4-6-6-2 is a steam locomotive with four leading wheels (two axles) in an unpowered bogie at the front of the locomotive followed by two sets of driving wheels with six wheels each (three axles each), followed by two unpowered trailing wheels (one axle) at the rear of the locomotive.Other equivalent classifications are:UIC classification: 2CC1 (also known as German classification and Italian classification)French classification: 230+031Turkish classification: 35+34Swiss classification: 3/5+3/4This locomotive wheel arrangement was used only in the United States of America and a very limited number of locomotives in North America, most notably as class MM-2 cab forward locomotives on the Southern Pacific Railroad. These were effectively 2-6-6-4s running in reverse. They were originally built as 2-6-6-2s but were refitted with a four-wheel leading truck to increase stability at speed. Such as the Southern Pacific AM-2's Built from July to August 1911 by Baldwin Locomotive Works as Cab Forwards. These 4-6-6-2's began Retirement in the Mid to Late 1930's, a Few Locomotives with this Arrangement were in Operation till the End of World War II. No Locomotives were Preserved with this Configuration.

4-Amino-2-(trifluoromethyl)-benzonitrile

4-Connected

Fred Katz Hal Gaylor & Johnny Pisano

4-Coumarate-CoA ligase

SAR Class GF, the first

2-(4-Bromo-3,5-dimethoxy-phenyl)-1-methyl-ethylamine

4-Ball

A 4-4-6-4, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is one that has four leading wheels followed by four coupled driving wheels, a second set of six coupled driving wheels and four trailing wheels.The Pennsylvania Railroad's Q2 class were the only locomotives ever to use this arrangement. These were duplex locomotives, in which both sets of driving wheels were mounted in a common, rigid locomotive frame.

4-DAMP (1,1-dimethyl-4-diphenylacetoxypiperidinium iodide) is a selective muscarinic acetylcholine receptor (mAChR) M3 antagonist. It is also able to antagonize M1 receptors but "prefers" M3. It competitively binds to the acetylcholine binding site on mAChRs, causing right-ward shift in the dose response curves for mAChR agonists.

4-Allyl-2-methoxyphenol

Diagram of two small leading wheels, three large driving wheels joined by a coupling rod, two small trailing wheels, three large driving wheels joined by a coupling rod, and two small leading wheels

Under the Whyte notation for the classification of steam locomotives, 4-8-4 represents the wheel arrangement of four leading wheels on two axles, eight powered and coupled driving wheels on four axles and four trailing wheels on two axles. The type was first used by the Northern Pacific Railway and is consequently most commonly known as a Northern.

4-4-5 calendar

4-Chlordehydromethyltestosterone

"4-Day Weekend"

Skeletal Structure of 4-Bromofluorobenzene

Space-filling model of the 4-cyano-4'-pentylbiphenyl molecule

Baldwin Locomotive Works

Space-filling model of the 4-aminoquinoline molecule

4-Desoxyadermin

Beyer Garratt 6594.jpg

4-3 duoprism

Double Pacific

4-ABP

ODVLAYUXIAMBFN-UHFFFAOYSA-N

Range includes:

Under the Whyte notation for the classification of steam locomotives, 4-2-2 represents the wheel arrangement of four leading wheels on two axles, two powered driving wheels on one axle, and two trailing wheels on one axle.Other equivalent classifications are:UIC classification: 2A1 (also known as German classification and Italian classification)French classification: 211Turkish classification: 14Swiss classification: 1/4Like other steam locomotive types with single pairs of driving wheels, they were also known as singles.

4-3-1 Eight-man Football Defense

4-D Film

4-Chlorophenoxyacetic acid

4-AcO-MiPT (4-acetoxy-N-methyl-N-isopropyltryptamine or mipracetin) is a psychedelic tryptamine. It is closely related to O-acetylpsilocin and MiPT.There is very little information on the human pharmacology or toxicity of 4-AcO-MiPT, although analytical methods have been developed for its detection.

p-Aminophenol; para-Aminophenol

but likely covered by analog act provisions as an analog of α-PVP

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the 4-8-0+0-8-4 is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-8-0 locomotives operating back to back, with the boiler and cab suspended between the two engine units. Each engine unit has two pairs of leading wheels in a leading bogie, followed by four coupled pairs of driving wheels and no trailing wheels.

4-4-2 formation

4-Aminohexenoic acid

Skeletal formula of PABA

4-Androstenediol, also known as androst-4-ene-3β,17β-diol, is an androstenediol that is converted to testosterone. The conversion rate is about 15.76%, almost triple that of 4-androstenedione, due to utilization of a different enzymatic pathway.

4-Bromo-2,5-dimethoxy-benzylpiperazine

4-Bromomethcathinone

4-D Warriors

In Whyte notation, a 4-6-4-4 is a railroad steam locomotive that has four leading wheels followed by six coupled driving wheels, a second set of four driving wheels and four trailing wheels.Other equivalent classifications are:UIC classification: 2CB2 (also known as German classification and Italian classification)French classification: 2322Turkish classification: 3524Swiss classification: 3/5+2/4 up to the early 1920s, later 5/9The sole example of this arrangement was the PRR Q1. This locomotive was essentially a prototype in the development of the PRR Q2, a 4-4-6-4.

4-4 defense

4-Bromo-2,5-dimethoxybenzeneethanamine

Uncontrolled

4-4 duopyramid

May 1937

PABA
para-Aminobenzoic acid

4-Bolt Mains

4-Bromo-2,5-dimethoxy-1-benzylpiperazine

4-Chlorodehydromethyltestosterone

4-Aminobiphenyl is an amine derivative of biphenyl. It is currently used to manufacture azo dyes. However, since it is a known human carcinogen, it has been largely replaced by less toxic compounds in other applications.

4-Amino-2-(trifluoromethyl)benzonitrile

4-Bromo-2,5-dimethoxy-a-methylphenethylamine

4-Androstenediol dipropionate

4-Chloro-o-toluidine (4-COT, 4-chloro-2-methylaniline) is the organic compound with the formula CH3C6H3Cl(NH2). It is a colorless solid. The compound is produced as an intermediate to the pesticide chlordimeform and a precursor to some azo dyes. Production has declined after it was shown to be highly carcinogenic.

4-AcO-DALT

4-3 defensive set

4-By The Beatles

4-Cyano-2-dimethylamino-4,4-diphenylbutane

India

4-Allylanisole

Ralph P. Johnson

4-Cl-IAA

4-Deoxypyridoxol

A 4-4-6-4, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is one that has four leading wheels followed by four coupled driving wheels, a second set of six coupled driving wheels and four trailing wheels.The Pennsylvania Railroad's Q2 class were the only locomotives ever to use this arrangement. These were duplex locomotives, in which both sets of driving wheels were mounted in a common, rigid locomotive frame. This locomotive design was a further development of the highly successful 2-10-4. The divided drive, or duplex arrangement, allowed for higher speeds with less damage to the track.Other equivalent classifications are:UIC classification: 2BC2 (also known as German classification and Italian classification)French classification: 2232Turkish classification: 2435Swiss classification: 2/4+3/5 up to the early 1920s, later 5/9

4-Desoxy-MDA

Sega System 1 hardware

4-4-0 locomotive

4-AT

4-4-1 (also written as "441") are an alternative-pop Christian rock band who played primarily in the 1980s. 4-4-1 consisted of lead singer/guitarist John McNamara, drummer Steve Giali, lead guitarist John Giali and bassist/keyboardist Glenn Holland.

3-{2-[Di(prop-2-en-1-yl)amino]ethyl}-1H-indol-4-yl acetate

4-Alpha-hydroxyphenylpyruvate hydroxylase deficiency

4-Cresol dehydrogenase

4-Acetoxy-DMT

5-Chloro-2-benzofuran-1,3-dione

4-Androstene-3,17-dione

Decreased wheelbase

In Whyte notation, a 4-6-6-2 is a steam locomotive with four leading wheels (two axles) in an unpowered bogie at the front of the locomotive followed by two sets of driving wheels with six wheels each (three axles each), followed by two unpowered trailing wheels (one axle) at the rear of the locomotive.Other equivalent classifications are:UIC classification: 2CC1 (also known as German classification and Italian classification)French classification: 230+031Turkish classification: 35+34Swiss classification: 3/5+3/4This locomotive wheel arrangement was used only in the United States of America and a very limited number of locomotives in North America, most notably as class MM-2 cab forward locomotives on the Southern Pacific Railroad.

4-Aminobenzenesulfonamide

4-D Boxing

4-227 ARB

4-By The Beatles (EP)

4-Chlorophenoxyacetic acid or parachlorophenoxyacetate (pCPA) is a synthetic pesticide similar to chemicals in a group of plant hormones called auxins.

Diagram of one small leading wheel, and four large driving wheels joined by a coupling rod

A 4-8-8-4 in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a locomotive with a four-wheel leading truck, two sets of eight driving wheels, and a four-wheel trailing truck. These are commonly known as "Union Pacific Big Boys".Other equivalent classifications are:UIC classification: '2DD2' (also known as German classification and Italian classification)French locomotive classification: '240+042'Turkish locomotive classification: '46+46'Swiss classification: '4/6+4/6'The equivalent UIC classification is refined to '(2′D)D2′' for Mallet locomotives.4-8-8-4 Big Boys were only produced for the Union Pacific Railroad. Twenty-five such engines were built between 1941 and 1944, numbered 4000 to 4024. Eight of these locomotives survive, all on static public display at various sites in the United States. Union Pacific has announced plans to restore No. 4014 to operation for use in mainline excursion service. No. 4014 is expected to be operational by 2019.The UP Big Boys were an expansion of the 4-6-6-4 "Challenger" type articulated locomotive. Although their wheels were an inch (25 mm) smaller than those of the Challengers, they were still able to sustain high speeds. Adding four driving wheels increased the pulling power of the locomotive and reduced the need for helper locomotives over steep grades.Other American railroads considered buying 4-8-8-4s, including the Western Pacific Railroad, which already rostered large 2-8-8-2s and 4-6-6-4s, but diesel locomotives were gaining popularity and soon were able to displace these Big Boy locomotives.

4-Androstenediol acetate propanoate

4-Amino-1,5-dimethyl-2-phenyl-3H-pyrazolone

4-Butyrolactone

Unscheduled

4-CMA

4-Chloroindole-3-acetic acid (4-Cl-IAA) is an organic compound that functions as a plant hormone. It is a member of the class of compounds known as auxins and a chlorinated derivative of the more common auxin indole-3-acetic acid (IAA). 4-Cl-IAA is found in the seeds of a variety of plants, particularly legumes such as peas and broad beans.

4-Cyano-3-(trifluoromethyl)aniline, also known as 4-amino-2-(trifluoromethyl)benzonitrile, is a cyanated and trifluoromethylated derivative of aniline. It is the starting material in one of the chemical syntheses of the nonsteroidal antiandrogen bicalutamide.

Androst-4-en-3β-ol-17-one

Soul° Cello

4-Chloro-2,5-Dimethoxy-phenethylamine

4-Chloroindole-3-acetic acid (4-Cl-IAA) is an organic compound that functions as a plant hormone. It is a member of the class of compounds known as auxins and a chlorinated derivative of the more common auxin indole-3-acetic acid (IAA). 4-Cl-IAA is found in the seeds of a variety of plants, particularly legumes such as peas and broad beans. It is hypothesized that 4-Cl-IAA may be a "death hormone" that maturing seeds use to trigger death of the parent plant by mobilizing nutrients to be stored in the seed.

4-8 duopyramid

4-4 point

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the 4-8-0+0-8-4 is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-8-0 locomotives operating back to back, with the boiler and cab suspended between the two engine units. Each engine unit has two pairs of leading wheels in a leading bogie, followed by four coupled pairs of driving wheels and no trailing wheels. Since the 4-8-0 type is known as a Mastodon type, the corresponding Garratt type would be referred to as a Double Mastodon. A similar wheel arrangement exists for Mallet locomotives, but is referred to as 4-8-8-4.

Z80, Sound Chips : SN76496, SN76496

"Keep the Home Fires Burning"

4-DOP

In enzymology, a 4-cresol dehydrogenase (hydroxylating) (EC 1.17.99.1) is an enzyme that catalyzes the chemical reaction4-cresol + acceptor + H2O ⇌ {\displaystyle \rightleftharpoons } 4-hydroxybenzaldehyde + reduced acceptorThe 3 substrates of this enzyme are 4-cresol, acceptor, and H2O, whereas its two products are 4-hydroxybenzaldehyde and reduced acceptor.This enzyme belongs to the family of oxidoreductases, specifically those acting on CH or CH2 groups with other acceptors.

4-4-0 American

4-Cyano-3-trifluoromethylaniline

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, a 4-4-2+2-4-4 is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-4-2 locomotives operating back to back, with each power unit having four leading wheels on two axles in a leading bogie, four powered and coupled driving wheels on two axles, and two trailing wheels on one axle in a trailing truck. Since the 4-4-2 type is usually known as an Atlantic, the corresponding Garratt type is often referred to as a Double Atlantic.

4-DHEA

4-Chloromercuribenzoic acid

Clc1cccCCCC

Decca Studios, Hollywood, CA

Up to 2 players, alternating turns

Under the Whyte notation for the classification of steam locomotives, 4-2-2-0 represents the wheel arrangement of four leading wheels on two axles, four powered but uncoupled driving wheels on two axles, and no trailing wheels. The arrangement became known as double single.

4-72 Colombia

4-Chlorophenylisobutylamine

4-Deoxypyridoxine is a vitamin B6 antagonist. It may be toxic to developing embryos since it can have negative effects on collagen and elastin during development. The presence of this compound can produce vitamin B6 deficiency, which suppresses the immune system. This immunosuppression can be beneficial in animal models of Trichinella spiralis infections.

4-2-5 defense

In enzymology, a 4-cresol dehydrogenase (hydroxylating) (EC 1.17.99.1) is an enzyme that catalyzes the chemical reaction4-cresol + acceptor + H2O ⇌ {\displaystyle \rightleftharpoons } 4-hydroxybenzaldehyde + reduced acceptorThe 3 substrates of this enzyme are 4-cresol, acceptor, and H2O, whereas its two products are 4-hydroxybenzaldehyde and reduced acceptor.This enzyme belongs to the family of oxidoreductases, specifically those acting on CH or CH2 groups with other acceptors. The systematic name of this enzyme class is 4-cresol:acceptor oxidoreductase (methyl-hydroxylating). Other names in common use include p-cresol–(acceptor) oxidoreductase (hydroxylating), and p-cresol methylhydroxylase. This enzyme participates in toluene and xylene degradation. It has 2 cofactors: FAD, and Cytochrome c.

Bristol and Exeter Railway

4-Chlorophenylpiperazine

4-AcO-DMT

4-2-4 (locomotive)

4-Chloroamphetamine

4-Acetoxy-DET

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the 4-6-0+0-6-4 is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-6-0 ten-wheeler locomotives operating back to back, with the boiler and cab suspended between the two swivelling power units.

KUR EC3 class, the first Double Northern Garratt, 1939

4-Cyano-4'-pentylbiphenyl is a commonly used nematic liquid crystal with the chemical formula C18H19N. It frequently goes by the common name 5CB. 5CB was first synthesized by George William Gray, Ken Harrison, and J.A. Nash at the University of Hull in 1972 and at the time it was the first member of the cyanobiphenyls.

4-D film

4-2-1 engine exhaust systems for automobiles are designed to ease the flow of exhaust gases of combustion leaving an internal combustion engine, thereby achieving optimal power output.

4-Bromofluorobenzene

4-Aminobiphenyl

Kenya & Uganda

4-D geometry

John Giali

4-Aminohippuric acid

4-D cinema

ClC1=CC=CC=C1

4-Chloromercuribenzoic acid (p-chloromercuribenzoic acid, PCMB) is an organomercury compound that is used as a protease inhibitor, especially in molecular biology applications.PCMB reacts with thiol groups in proteins and is therefore an inhibitor of enzymes that are dependent on thiol reactivity, including cysteine proteases such as papain and acetylcholinesterase. Because of this reactivity with thiols, PCMB is also used in titrimetric quantification of thiol groups in proteins.

4-Aminoacridine

South Africa

4-Crotonolactone

Under the Whyte notation for the classification of steam locomotives, 4-2-4 represents the wheel arrangement of four leading wheels on two axles, two powered driving wheels on one axle, and four trailing wheels on two axles. This type of locomotive is often called a Huntington type.The configuration was most often used for tank engines, which is noted by adding letter suffixes to the configuration, such as 4-2-4T for a conventional side-tank locomotive, 4-2-4ST for a saddle-tank locomotive, 4-2-4WT for a well-tank locomotive and 4-2-4RT for a rack-equipped tank locomotive.

4-dimethylallyltryptophan N-methyltransferase (EC 2.1.1.261, fgaMT (gene), easF (gene)) is an enzyme with systematic name S-adenosyl-L-methionine:4-(3-methylbut-2-enyl)-L-tryptophan N-methyltransferase.

4-Chlorotoluene

American Locomotive Company

4-Androstenediol acetate butyrate

4-Aminophenazone

4-Azasteroids

4-Aminoaniline

4-2-1 phenomenon

4-AP

4-Acetylpsilocin

Decca( DL 9213)

BDZUAWTZJXBMLX-UHFFFAOYSA-N

A 4-4-6, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a locomotive with:four (4) leading wheels (at the front of the locomotive)four (4) driving wheels (2 axles) fixed in a rigid frame, andsix (6) trailing wheels (normally mounted in a trailing truck).An example of this wheel arrangement was the Thuile locomotive.Other equivalent classifications are:UIC classification: 2'B3' (also known as German classificationItalian classification), andFrench classification: 223.

4-DDE

4-DAMP

4-Dimethylaminoazobenzene

Diagram of two small leading wheels, six large driving wheels in two trios, each trio joined by coupling rods, and two small trailing wheels

4-C

Anlage I

C[C@]12CC[C@H]3[C@H]CCC4=C[C@H]O

4-Cyano-1-methyl-4-phenyl-piperidine

Brazil

4-3 Defense

Diagram of two small leading wheels, four large driving wheels joined by a coupling rod, four small trailing wheels, four large driving wheels joined by a coupling rod, and two small leading wheels

4-Coumarate—CoA ligase

Baltimore and Ohio Railroad

p-Aminodiphenyl

4-Chloro-alpha-pyrrolidinovalerophenone

4-20mA current loop

4-Androstenediol dipropanoate

4-AcO-MiPT

4-Bromo-N-methylcathinone

4-Androstenediol

Space Filling Model of 4-Bromofluorobenzene

United States

4-Aminobenzoic acid

Steve Giali

4-Chlorotestosterone

4-Chlorophthalic Anhydride

[3-[2-[Isopropylamino]ethyl]-1H-indol-4-yl] acetate

In Whyte notation, a 4-6-4-4 is a railroad steam locomotive that has four leading wheels followed by six coupled driving wheels, a second set of four driving wheels and four trailing wheels.Other equivalent classifications are:UIC classification: 2CB2 (also known as German classification and Italian classification)French classification: 2322Turkish classification: 3524Swiss classification: 3/5+2/4 up to the early 1920s, later 5/9The sole example of this arrangement was the PRR Q1.

4-Asma Kəsmə

4-Dimensional Printing

4-Asma Kesme

Under the Whyte notation for the classification of steam locomotives, a 4-8-8-2 is a locomotive with four leading wheels, two sets of eight driving wheels, and a two-wheel trailing truck.Other equivalent classifications are:UIC classification: 2DD1 (also known as German classification and Italian classification)French classification: 240+041Turkish classification: 46+45Swiss classification: 4/6+4/5The equivalent UIC classification is refined to (2'D)D1' for Mallet locomotives.A locomotive of that length must be an articulated locomotive; meaning all have a joint between the first and second groups of driving wheels. All examples of this type are cab forwards. Normally, the leading truck sits under the smokebox and the trailing truck under the firebox. On a cab-forward, the leading truck supports the firebox and the trailing truck and smokebox are at the rear next to the tender. A 4-8-8-2 is effectively a 2-8-8-4 that always runs in reverse. Although commonly called Mallets these cab-forwards were built with simple expansion cylinders. The name stuck because the original classes of Southern Pacific cab-forwards were built as compound Mallets, though these were also eventually converted to simple expansion.

p-Chloromercurybenzoic acid; p-Chloromercuribenzoate; 4-Chloromercuribenzoate

Diagram of two small leading wheels, two large driving wheels joined by a coupling rod, two small trailing wheels, two large driving wheels joined by a coupling rod, and two small leading wheels

Androst-4-ene-3β,17β-diol

Diagram of two small leading wheels, four large driving wheels joined by a coupling rod, and two small trailing wheels

4-Chlorophenylisobutylamine (4-CAB, AEPCA), also known as 4-chloro-α-ethylphenethylamine, is an entactogen and stimulant drug of the phenethylamine class. It is an analogue of para-chloroamphetamine (PCA) where the alpha position methyl has been replaced with an ethyl group.In comparison to PCA, 4-CAB is approximately 2- and 5-fold less potent at inhibiting the reuptake of serotonin (IC50 = 330 nM) and dopamine (IC50 = 2,343 nM), respectively, and is about 3-fold less potent in substituting for MDMA in animals in drug discrimination assays. Though its dopaminergic activity is significantly attenuated compared to PCA, unlike the case of MBDB, it is not abolished, and is actually similar to that of MDMA.Relative to PCA, 4-CAB is also substantially less effective as a serotonergic neurotoxin. A single 10 mg/kg administration of PCA to rats produces an approximate 80% decrease in serotonin markers as observed 1 week later. In contrast, 11 mg/kg and 22 mg/kg doses of 4-CAB result in only 20% and 50% decreases, respectively. This is once again similar to MDMA which causes a 40-60% reduction with a single 20 mg/kg dose.

4-Cyano-4'-pentylbiphenyl

4-Chloromethandienone

Brainstorm Artists, Intl

Horizontal

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the 4-8-4+4-8-4 is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-8-4 locomotives operating back to back, with the boiler and cab suspended between the two engine units. Each engine unit has two pairs of leading wheels in a leading bogie, followed by four coupled pairs of driving wheels and two pairs of trailing wheels in a trailing bogie. Since the 4-8-4 type is sometimes known as a Northern, the corresponding Garratt type would be referred to as a Double Northern.

3,5-Methoxy-4-trideuteromethoxyphenethylamine

4-AcO-MET

4-Androstenediol acetate butanoate

The Baltimore & Ohio Railroad's #5600 George H. Emerson.

4-Benzylpiperidine

4-Coumarinol

4-CMC

4-Cross

[1,1'-Biphenyl]-4-amine

Space-filling model of the 4-chloroindole-3-acetic acid molecule

Bacterial vitamin H1

4-Azidocoumarin

4-Coumaroyl

Bengal Nagpur Railway class N No. 815

4-Amino-3,5,6-trichloro-2-picolinic acid

4-D (psychedelic)

Pearson 4-2-4T

April 1942

Mogyana Railway

In enzymology, a 4-coumarate-CoA ligase (EC 6.2.1.12) is an enzyme that catalyzes the chemical reactionATP + 4-coumarate + CoA ⇌ {\displaystyle \rightleftharpoons } AMP + diphosphate + 4-coumaroyl-CoAThe 3 substrates of this enzyme are ATP, 4-coumarate, and CoA, whereas its 3 products are AMP, diphosphate, and 4-coumaroyl-CoA.This enzyme belongs to the family of ligases, to be specific those forming carbon-sulfur bonds as acid-thiol ligases. The systematic name of this enzyme class is 4-coumarate:CoA ligase (AMP-forming). Other names in common use include 4-coumaroyl-CoA synthetase, p-coumaroyl CoA ligase, p-coumaryl coenzyme A synthetase, p-coumaryl-CoA synthetase, p-coumaryl-CoA ligase, feruloyl CoA ligase, hydroxycinnamoyl CoA synthetase, 4-coumarate:coenzyme A ligase, caffeolyl coenzyme A synthetase, p-hydroxycinnamoyl coenzyme A synthetase, feruloyl coenzyme A synthetase, sinapoyl coenzyme A synthetase, 4-coumaryl-CoA synthetase, hydroxycinnamate:CoA ligase, p-coumaryl-CoA ligase, p-hydroxycinnamic acid:CoA ligase, and 4CL. This enzyme participates in phenylpropanoid biosynthesis.

4-Androstenediol acetate propionate

ABGXADJDTPFFSZ-UHFFFAOYSA-N

4-BMC

4-CLTA

4-Ball (billiards)

Pearson 4-2-4T no. 44 of the Bristol and Exeter Railway, c. 1854

Illegal in China and Sweden

p-Fluorophenyl bromide

Raster, 256 x 224 pixels, 1536 colors

4-Aminophenol

C1CNCCC1CC2=CC=CC=C2

4-D (comics)

4-Azasteroid

4-dimethylallyltryptophan N-methyltransferase (EC 2.1.1.261, fgaMT (gene), easF (gene)) is an enzyme with systematic name S-adenosyl-L-methionine:4-(3-methylbut-2-enyl)-L-tryptophan N-methyltransferase. This enzyme catalyses the following chemical reactionS-adenosyl-L-methionine + 4-dimethylallyl-L-tryptophan ⇌ {\displaystyle \rightleftharpoons } S-adenosyl-L-homocysteine + 4-dimethylallyl-L-abrineThe enzyme catalyses a step in the pathway leading to biosynthesis of ergot alkaloids in certain fungi.

4-Amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one

Skeletal formula of 4-chloroindole-3-acetic acid

Ball-and-stick model of the 4-dehydroepiandrosterone molecule

4-4-2 locomotive

4-Androsten-3,17-dione

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, a 4-4-2+2-4-4 is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-4-2 locomotives operating back to back, with each power unit having four leading wheels on two axles in a leading bogie, four powered and coupled driving wheels on two axles, and two trailing wheels on one axle in a trailing truck.

4-CA

4-Coumaroyl-CoA

4-Aminobutyrate aminotransferase

4-20 mA loop

In Whyte notation, a 4-6-6-4 is a railroad steam locomotive that has four leading wheels followed by six coupled driving wheels, a second set of six driving wheels and four trailing wheels. 4-6-6-4's are commonly known as Challengers. Challengers were most common in the Union Pacific Railroad and the Clinchfield Railroad.This locomotive was impressive and widely used by the Union Pacific for passenger service but was mostly used for freight.

4-B

4-C's of Diamond Grading

4-Aminophenol (or para-aminophenol or p-aminophenol) is the organic compound with the formula H2NC6H4OH. Typically available as a white powder, it was commonly used as a developer for black-and-white film, marketed under the name Rodinal.Reflecting its slightly hydrophilic character, the white powder is moderately soluble in alcohols and can be recrystallized from hot water. In the presence of a base, it oxidizes readily. The methylated derivatives N-methylaminophenol and N,N-dimethylaminophenol are of commercial value.The compound is one of three isomeric aminophenols, the other two being 2-aminophenol and 3-aminophenol.

4-Cyano-1-methyl-4-phenylpiperidine

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, a 4-6-2+2-6-4 is a Garratt or Union Garratt articulated locomotive using a pair of 4-6-2 engine units back to back, with the boiler and cab suspended between them. The 4-6-2 wheel arrangement of each engine unit has four leading wheels on two axles, usually in a leading bogie, six powered and coupled driving wheels on three axles, and two trailing wheels on one axle, usually in a trailing truck. Since the 4-6-2 type is known as a Pacific, the corresponding Garratt type is usually known as a Double Pacific.

4-Desoxymescaline

4-Cl-KYN

4-4 duoprism

Skeletal formula of 4-aminophenol

Skeletal formula of 4-dehydroepiandrosterone

4-Amino-2-trifluoromethyl-benzonitrile

1,1-Dimethyl-4-diphenylacetoxypiperidinium iodide

4-Chloromethcathinone

Under the Whyte notation for the classification of steam locomotives, 4-4-4 represents the wheel arrangement of four leading wheels on two axles, four powered and coupled driving wheels on two axles, and four trailing wheels on two axles. In the United States, this arrangement was named the Reading type, since the Philadelphia and Reading Railroad was the first to use it. In Canada, this type is known as the Jubilee.Other equivalent classifications are:UIC classification: 2B2 (also known as German classification and Italian classification)French classification: 222Turkish classification: 26Swiss classification: 2/6

p-Bromofluorobenzene

4-Deoxypyridoxine Hydrochloride