Effect of cylinder power and axis changes on vision in astigmatic participants.

PURPOSE: To ascertain the impact of altering cylinder (cyl) power and axis on vision in astigmatism. METHODS: In a prospective, randomized, participant-masked, crossover clinical trial, 28 astigmatic participants were tested for the following conditions on different days: full sphero-cyl correction and undercorrection by 0.25, 0.50, and 0.75 DC while maintaining spherical equivalence. Axis was also misaligned between -30° and +30°, in 10° steps. For each configuration, monocular high- and low-contrast visual acuities (HCVA, LCVA) were measured at 6 m, and participants rated vision clarity (1-10), vision satisfaction (1-10), and vision acceptability (yes/no). Linear mixed models were used to compare visual performance in the overall group and in low, medium, and high cyl subgroups. RESULTS: Undercorrecting cyl power affected all groups equally (P≥0.073). Undercorrection by 0.75 DC was significantly different to full cyl power for all variables (P≤0.007), while 0.25 DC undercorrection did not cause any significant decreases (P>0.05). Undercorrection by 0.50 DC was significantly different to full cyl power for HCVA (P=0.006, however not clinically significant) and vision acceptability (P=0.034). Axis misalignment affected the cyl groups differently (P<0.001), with the greatest impact in the high cyl group, followed by the medium then the low-cyl group. Misalignment by ±30° caused significant decreases in almost all cases (P≤0.003), while misalignments by ±10° or ±20° caused significant decreases for some cyl groups and test variables. CONCLUSION: Undercorrection of cyl by ≤0.50 DC while maintaining spherical equivalence has no significant effect on HCVA, LCVA, vision clarity, and vision satisfaction, while the amount of axis misalignment that can be tolerated is dependent on the cyl power. These results may have practical ophthalmic applications, such as reducing the total number of stock keeping units of toric contact lenses.

Mode of action of new diethylamines in lycopene cyclase inhibition and in photosystem II turnover.

The new bleaching herbicidal compound N,N-diethyl-N-(2-undecynyl)amine (NDUA) is identified here as an inhibitor of lycopene cyclase and is compared with the known cyclase inhibitors N,N-diethyl-N-[2-(4-chlorophenylthio)ethyl]amine (CPTA) and N,N-diethyl-N-[2-(4-methylphenoxy)ethyl]amine (MTPA). HPLC separation of chloroplast pigments shows lycopene accumulation in NDUA treated tissue. Variation in chain length of the undecynylamine moeity of NDUA from 7 to 21 C atoms reveals an optimum of 11 to 14 C atoms for herbicidal activity. A series of seven further analogues of NDUA and CPTA reveals the structural elements necessary for inhibition of lycopene cyclase. The effect of NDUA derivatives on photosynthesis has been studied in Chlamydomonas reinhardtii. Photosynthesis is highly sensitive, particularly towards the C14 and longer chain length analogues at nanomolar concentrations. It is shown that the breakdown of photosynthesis by NDUA is due to interference with the turnover of the D1 protein of the photosystem II reaction centre that requires the continuous biosynthesis of the two reaction-centre beta-carotene moieties in the reassembly phase. The D1 protein disappearance is most marked under strong light conditions. The depletion of photosystem II occurs before total pigment bleaching. This newly recognized mechanism in herbicidal activity is also the basis for the mode of action of other lycopene cyclase inhibitors as well as phytoene desaturase inhibitors.

Detection of T1-oligonucleotides of the foot-and-mouth disease virus RNA [correction of DNA] by silver staining.

Viral (v) RNA was isolated from purified foot-and-mouth disease virus (FMDV) by phenol-chloroform-isoamylalcohol treatment, digested by RNase T1 and separated by one-dimensional polyacrylamide gel electrophoresis (PAGE). The oligonucleotides were detected by silver staining. About 45 micrograms of vRNA corresponding to about 100 ml of infectious BHK-21 cell culture fluid yielded a pattern of nearly 20 bands sufficient to differentiate between the FMD viruses.

Studies on optically active pesticides, I synthesis and herbicidal activity of d(+) and 1(-) methyl-2-chloro-3-(4-chlorophenyl)-propionate.

d(+) and 1(-) Methyl-2-chloro-3-(4-chlorophenyl)-propionate (common name chlorfenprop-methyl; trade mark Bidisin) were prepared and their herbicidal activities studied on Avena fatua L. and Avena sativa L. ("Flämingskrone"). The 1(-) enantiomer was found to be twice as active as the racemate; the d(+) form almost inactive.