Terminal branch

Allergic alveolitis An allergic response to inhalation of organic particles that involves inflammation of the small terminal branches of the bronchioles. Symptoms include coughing, increased production of mucus, fever, fatigue, and muscle aches. 

Reaction Mechanism. The reaction mechanism of the anionic-solution polymerization of styrene monomer using n-butyllithium initiator has been the subject of considerable experimental and theoretical investigation (1-8). The polymerization process occurs as the alkyllithium attacks monomeric styrene to initiate active species, which, in turn, grow by a stepwise propagation reaction. This polymerization reaction is characterized by the production of straight chain active polymer molecules ("living" polymer) without termination, branching, or transfer reactions. 

Rule 2. Terminal branching stabilizes alkanes more than inner branching. 

Terminal branching gives one more cross conjugation number (nj) than inner branching (Scheme 25b). For example, the number is 2 for 2-methylpentane and 1 for 3-methylpentane, in agreement with the relative stability. Inner branched isomers have almost the same heat of formation. For example, the difference is very small (0.12 kcal moF ) between 3- and 4-methylheptanes (n = 1). 

Synapses between the autonomic postganglionic neuron and effector tissue — the neuroeffector junction — differ greatly from the neuron-to-neuron synapses discussed previously in Chapter 5 (see Table 9.1). The postganglionic fibers in the ANS do not terminate in a single swelling like the synaptic knob, nor do they synapse directly with the cells of a tissue. Instead, the axon terminals branch and contain multiple swellings called varicosities that lie across the surface of the tissue. When the neuron is stimulated, these varicosities release neurotransmitter over a large surface area of the effector tissue. This diffuse release of the neurotransmitter affects many tissue cells simultaneously. Furthermore, cardiac muscle and most smooth muscle have gap junctions between cells. These specialized intercellular communications... 

The reaction rates of various types of olefins follow much the same pattern with both cobalt- and rhodium-catalyzed systems. Wender and co-workers (47) classified the nonfunctional substrates as straight-chain terminal, internal, branched terminal, branched internal, and cyclic olefins. The results they obtained are given in Table III. 

A very important question in the context of dendrimers and their utility as host molecules relates to the existence of cavities within these macromolecules. The presence of internal voids in dendrimers is closely related to their conformational behaviour and to the degree of back-folding of the terminal branches into the interior of the dendrimer. The issue of back folding was already briefly touched upon in section 16.2.1. Next to the purely theoretical calculations mentioned there, several calculations have been performed on specific dendrimer types. 

Fig. 9. The unrooted tree top) shows unequal rates of evolution along the terminal branches. Applying the UPGMA method to the underlying sequences results in the tree at the bottom, which incorrectly joins sequences 2 and 4.

Thanassi, D. G., Saulino, E. T., and Hultgren, S.J. (1998). The chaperone/usher pathway a major terminal branch of the general secretory pathway. Curr. Opin. Microbiol. 1, 223-231. 

Classically the liver has been divided into hexagonal lobules centred around the terminal hepatic venules. Blood enters the liver through the portal tracts that are situated at the corners of the hexagon. The portal tracts are triads of a portal vein, an hepatic artery, and a common hepatic bile duct. The vast expanse of hepatic tissue, mostly consisting of parenchymal cells (PC) or hepatocytes, is serviced via terminal branches of the portal vein and hepatic artery, which enters the tissue at intervals. The hepatocytes are organized into cords of cells radially disposed about the central hepatic venule. Between these cords are vascular sinusoids that transport the blood to the central hepatic venules. The blood is collected through the hepatic venules into the hepatic vein which exits the liver into the inferior vena cava (Figure 4.1). 

In the autonomic ganglia, the varicosities in the terminal branches of the preganglionic axons come into close contact primarily with the dendrites of the ganglionic cells and make synaptic connection with them. 

Conduction of an action potential through the terminal branches of an axon causes depolarization of the varicosity membrane, resulting in the release of transmitter molecules via exocytosis. Once in the junctional extracellular space (biophase), acetylcholine interacts with cholinoreceptors. 

Cypress oil is produced by steam distillation of terminal branches of Cupressus sempervirens L. (Cupressaceae). It is a liquid with a wood-like odor that has an ambergris note. 

Eucalyptus citriodora oil is obtained by steam distillation of leaves and terminal branches of Eucalyptus citriodora Hook. It is an almost colorless, pale yellow, or greenish-yellow liquid with a citronellal-like odor. 

The microcrystalline or amorphous waxes separated from the crude fractions boiling above paraffin distillate are predominantly of the naphthene-containing paraffin structure (62, 70). Thus urea adducting of 149° to 165° F. melting point wax (Superla of Indiana) isolated but 15% of adductive material assumed to be normal or terminally branched paraffins. The microcrystalline waxes consist mostly of hydrocarbon with 34 to 60 carbon atoms (70) and have a melting range from 140° to 200° F. (16). 

The u-deoxy sugars studied (6-deoxy and 5-deoxy) have intense peaks for the dithioacetal fragment, and also break down to Fragments A, B, and C. < -Deoxyhexose dithioacetals cannot be differentiated from 5-deoxy-hexose dithioacetals. The deoxy function is, apparently, too far removed from the bonds most susceptible to cleavage to have a significant effect. Mass spectrometry can also be useful in the characterization of terminal branched-chain deoxy sugars. The spectrum of 6-deoxy-5-C-methyl-D-xylo-hexose diethyl dithioacetal 1 contains prominent peaks due to Fragments A, B, and C. Apparently, substitution beyond C-4 does not affect... 

It is evident from the foregoing condensations that a branched chain inhibits the formation of a cyclic dichloro-tellurium derivative containing the bivalent diketone radical. Hence j8-diketones with terminal branched chains (RR CH.CO. and RR CH.CH2.CO.) cannot be employed in the production of yellow cyclic tellurium derivatives such as are obtained from w-butyrylacetone. 

To study the nucleation step for the folding of collagen, a protocol has been developed for the liquid-phase synthesis by which three peptide strands are covalently linked via a C-terminal branch. 70-73 The C-terminal branch is expected to enhance triple-helical thermal stability, and to provide a model of the disulfide-linked C-terminus of type III collagen. 71 ... 

Solid-Phase Assembly of an al(I)772-786 Triple-Helical Peptide Using a Lys-Lys C-Terminal Branch General Procedure 84-851... 

Assembly of triple-helical peptides using a Glu-Glu N-terminal branch requires two peptide types, one containing a Glu a-thioester at its N-terminus and one without the Glu (Scheme... 

To estimate inhalation contact exposure, some assumptions must be made which err on the side of conservatism and which should be modified as more complete data become available. It is necessary to know the droplet size spectrum of the spray because the diameter of the droplet influences its movement down the respiratory system (11). The functional unit of the lung is the alveolus, which is the terminal branch in the system. It is presumed that pesticide particles which are soluble in respiratory tract fluid and are 5p or less in diameter will reach the alveolus where they will be readily absorbed through the cells of the alveolar membrane into the pulmonary capillary beds and hence into the circulatory system. A recent review by Lippmann at al. (12) discusses in depth the deposition, retention and clearance of inhaled particles. 

At least one tert-buty terminal branch Highly branched chemicals Persistent... 

Fig. 4.10 (a) Molecule 1, methyl-terminated branches and (b) molecule 2, hydroxyl-terminated branches. Chemical structures are accompanied with molecular models. (From ref. [73])... 

Fig. 20. Study of a simple filament a Gray-level image (S. ambofatiens filament after INT staining) b binary image c skeleton d skeleton after removal of branching points e terminal branches f internal segments...

Sancho et al. (1989) used a similar procedure in rats ligating two of the three terminal branches of the left renal artery, followed by right nephrectomy. 

Examination of Fig. 37 shows that, at generation 8, the surface area per Z group in PAMAM dendrimers approaches the cross-sectional area of the amine-terminated branch segment (ca. 33 A2) of the surface cell. Curve B assumes quantitative reactions and 100% branching ideality at each stage. Since our present analytical methods assure branching ideality detection limits of no more than 95%, curve A may more nearly approximate experimental congestion levels. 

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