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B M O'Leary

Publications and source records attributed to B M O'Leary.

3 recordsLinked to original sources
PubMed2001

"Flexiball" toolkit: a modular approach to self-assembling capsules.

We report the synthesis and characterization of new, self-assembling molecular capsules. The modular strategy makes use of glycoluril building blocks available in multigram amounts combined with aromatic spacer elements. The lengthy syntheses encountered with earlier generations of capsules are avoided, and several capsules of nanometer dimensions are now accessible. Single bond attachments between spacers and glycoluril modules result in monomers as dimeric capsules that are less rigid than their earlier counterparts. The host-guest properties of the homo- and heterodimeric capsules were studied using a combination of NMR and ESI-mass spectrometry. They show a less pronounced selectivity for guests of different sizes, and their increased flexibility prevents self-assembly when no rigidifying elements are present on the central spacer unit. Some of the new capsules bear inwardly directed, secondary amide N-H protons. These can be further functionalized, as shown by their methylation to give tertiary analogues. The structures hold broader implications for the placement of functional groups on concave molecular surfaces.

Alkynes↗
PubMed1998

Pupillary dilatation and driving in diabetic patients.

Diabetic patients routinely have their pupils dilated for fundoscopy as part of the annual review. To assess the ability of diabetic patients to drive after pupillary dilatation we studied 61 diabetic patients (18 IDDM, 43 NIDDM), mean age 54.98 years, before and 1 h after pupillary dilatation with 1% tropicamide. Binocular visual acuity (BVA) and contrast sensitivity were checked without glare, with glare, and with glare and sunglasses. Glare was introduced using a 60 W bulb in all 61 patients and with a 500 W bulb in 37 of these patients. Prior to dilatation all 61 patients had a BVA of 6/9 or better. A significant reduction in BVA was found post-dilatation (p = 0.005) and 4 out of the 61 patients (6.56%) had a post-dilatation BVA of less than 6/9. The 60 W glare source caused a significant reduction in BVA pre-dilatation (p < 0.05), but not the 500 W glare. With glare, post-dilatation BVA reduced further, resulting in 6 and 7 patients having a BVA of less than 6/9 with the 60 W and 500 W glare source, respectively. The addition of sunglasses with glare did not improve the BVA. No patient with a BVA of 6/5 pre-dilatation reduced to less than 6/9 post-dilatation. No significant change in contrast sensitivity was found in any of the test conditions. We conclude that patients who meet the visual legal requirements to drive (BVA < or = 6/9) prior to dilatation may not fulfil them post-dilatation. This has important clinical implications and the time course of the phenomenon requires exploration. Meanwhile, patients need to be warned not to drive after pupillary dilatation when they attend for annual fundoscopic examination, certainly for at least two hours.

Adult↗