Writhe

Fig. 6. The envelope of the writhing number of closed circular DNA subject to torsional stress as a function of 7, as computed from Langevin trajectories. Data are from [31].

Fig. 7. Writhe distributions for closed circular DNA as obtained by LI (see Section 4.1) versus explicit integration of the Langevin equations. Data are from [36].

The linking difference can be considered in terms of changes in the twist, Tiv, and writh, Wr, of the molecule. Twist describes how the DNA strands are coHed around each other writh describes the coiling of the hehcal axis. The change in linking number is related to changes in twist and writh ... 

The native form of chromatin in cells assumes a higher order stmcture called the 30-nm filament, which adopts a solenoidal stmcture where the 10-nm filament is arranged in a left-handed cod (Fig. 5). The negative supercoiling of the DNA is manifested by writhing the hehcal axis around the nucleosomes. Chromatin stmcture is an example of toroidal winding whereas eukaryotic chromosomes are linear, the chromatin stmctures, attached to a nuclear matrix, define separate closed-circular topological domains. 

Note The above example is only for a general reference. The CDF of the transformer, for the short-time rating, should be increased writh the starting time and the number of starts per hour. Refer to the transformer manufacturer for a more appropriate selection. 

DNA duplex of 400 bp, L is 40 (assuming 10 bp per turn in B-DNA). The linking number for relaxed DNA is usually taken as the reference parameter and is written as Lq. L can be equated to the twist (T) and writhe (W) of the duplex, where twist is the number of helical turns and writhe is the number of supercoils ... 

Reductive cyclization of 4-piperidinecarboxamide 562 afforded 563 which could be alternatively obtained by condensation of 564 with the respective cyclic amine. Compound 563 showed inhibition of writhing in mice (96EP700913). Similarly, 565 gave 566 (76JMC1111) (Scheme 94). 

The procedure recommended by Reference [18] is based on the conventional gas flow equations, writh some slight modifications. The importance in final line size determination is to determine w hat is a reasonable pressure loss at the absolute pressure required and the corresponding pipe size to balance these. In some cases a trial/error approach is necessary. 

YVe saw in Section 17.4 that keLones react with NaBH4 to yield alcohols. We ll also see in Section 22.3 that ketones react writh Br2 to yield a-bromo ketones. Perhaps surprisingly, treatment with NaBH4 of the a-bromo ketone from acetophenone yields an epoxide rather than a bromo alcohol. Show the structure of the epoxide, and explain its formation. 

The compounds 25a-c and 33a-f were tested for analgesic activity [ 14] by oral administration in mice in terms of the inhibition of the writhing syndrome induced by acetic acid. The ED50 which represents the dose producing 50% inhibition of the writhing induced by acetic acid was determined. The ED50 values of the compounds tested are summarized in Table 4. The pyrazolones 25a-c showed more potent analgesic activity than 1 and amino-pyrine. 

Equip a 1 litre three-necked flask writh a reflux condenser, a mechanical stirrer, and a cork carrying a dropping funnel and a thermometer which reaches nearly to the bottom of the flask connect the upper end of the condenser to an absorption trap (Fig. II, 8, 1). Place 100 g. of p-bromo-toluene (Section IV,62) in the flask and immerse the latter in an oil bath (colourless oil in a large beaker). Heat the bath until the temperature of the stirred p-broniotoluene reaches 105°. Illuminate the liquid with... 

Symptom Rating Scale (ESRS). Akathisia is commonly monitored by the Barnes Akathisia Scale (BAS). The emergence of dyskinesias (writhing or involuntary movements) could represent the emergence of TD. Monitor for TD at least annually, and if FGAs are used patients should be evaluated at each visit. The most commonly used instrument to measure these symptoms is the Abnormal Involuntary Movement Scale (AIMS). 

Tardive dyskinesia A chronic disorder of the nervous system characterized by involuntary jerky or writhing movements of the face, tongue, jaws, trunk, and limbs, usually developing as a late side effect of prolonged treatment with antipsychotic drugs. 

From Refs. 72 and 85. b Subcutaneous injection. c Phenylquinone writhing in mice. 

Kimura K, Rybenkov VV, Crisona NJ, Hirano T, Cozzarelli NR 1999 13S condensin actively reconfigures DNA by introducing global positive writhe implications for chromosome condensation. Cell 98 239-248... 

Mikania cordata is known to elaborate a series of sesquiterpene lactones, among which deoxymikanolide significantly inhibits acetic acid-induced writhing in mice (44,45). The plant also contains a series of melampolides that inhibit the enzymatic activity of elastase (46). 

Quite recently, a French group reported on the synthesis of 2-substituted 5-arylidene-pyridazinones as represented by the general formula (21, R1 = Ph, 2-ClC6H4 R2 = Ph(CH2)2, PhCO). These compounds were found to exhibit significant dose-dependent analgesic activity (phenylquinone-induced writhing test in mice oral administration) [92]. For a novel type of aminopyridazine-derived inhibitors of prostacyclin biosynthesis, see [93],... 

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