A quartz crystal microbalance method to quantify the size of hyaluronan and other glycosaminoglycans on surfaces.

Hyaluronan (HA) is a major component of peri- and extra-cellular matrices and plays important roles in many biological processes such as cell adhesion, proliferation and migration. The abundance, size distribution and presentation of HA dictate its biological effects and are also useful indicators of pathologies and disease progression. Methods to assess the molecular mass of free-floating HA and other glycosaminoglycans (GAGs) are well established.

Long-term monitoring of Vermont's forest soils: early trends and efforts to address innate variability.

Long-term monitoring of forest soils is necessary to understand the effects of continued environmental change, including climate change, atmospheric deposition of metals, and, in many regions, recovery from acidic precipitation. A monitoring program was initiated in 2002 at five protected forest sites, primarily Spodosol soils, in Vermont, northeastern USA. Every 5 years, ten soil pits were sampled from random subplots in a 50 × 50-m plot at each site.

The potential of memory enhancement through modulation of perineuronal nets.

With an increasingly aging global population, the incidence of neurological diseases such as dementia is set to increase to unmanageable levels, yet there are currently only symptomatic therapies available for treatment. The mechanisms underlying the development of some forms of dementia, such as Alzheimer's disease (AD), are not yet completely elucidated with several competing hypotheses existing. During the closure of the critical period in the brain, significant compositional changes occur to the neural extracellular matrix (ECM).

CASSCF Calculations Reveal Competitive Chair (Pericyclic) and Boat (Pseudopericyclic) Transition States for the [3,3] Sigmatropic Rearrangement of Allyl Esters.

(10,8)CASPT2/6-31G**//(10,8)CASSCF/6-31G** and CCSD(T)/cc-pVDZ//(10,8)-CASSCF/6-31G** calculations have been performed on the potential surface for the [3,3] sigmatropic allyl ester rearrangements of cis-3-penten-2-yl acetate (16) to trans-3-penten-2-yl acetate (17) and 3-buten-2-yl acetate (21) to trans-2-buten-1-yl acetate (22). The results are compared to DFT (B3LYP/6-31G**) calculations on the known 16 → 17 rearrangement that reported it to be concerted and pseudopericyclic through a boat-shaped transition structure ( Birney, D. M.

CASSCF Computational Study of Pseudopericyclic Character in Electrocyclic Rearrangements Involving Heteroatoms.

The Complete Active Space Self-Consistent Field (CASSCF) computational method, with the 6-31G* basis set, was used to examine six electrocyclic rearrangements, each involving a 1,2,4,6-heptatetraene skeleton with two variously located oxygen and/or nitrogen heteroatoms, as a way to determine which, if any, are pseudopericyclic as opposed to pericyclic. Primarily through the close examination of the active space orbitals, but also considering transition structure geometries and activation energies, it was concluded that rearrangements 3 → 4, 5 → 6, 7 → 8, and 9 → 10 are pseudopericyclic with two orbital disconnections each, whereas the 13 → 14 and 15 → 16 rearrangements are pericyclic. Our conclusions agreed with those of others in two of the four cases that had been studied previously by density functional theory (3 → 4 and 7 → 8) but ran contrary to the previous conclusions that the 5 → 6 rearrangement is pericyclic and that the 15 → 16 rearrangement is pseudopericyclic.

CASSCF molecular orbital calculations reveal a purely pseudopericyclic mechanism for a [3,3] sigmatropic rearrangement.

A comparative CASSCF/6-31G*-level computational study of the concerted [3,3] sigmatropic rearrangements of cis-1-iminyl-2-ketenylcyclopropane (15), cis-1-iminyl-2-propadienylcyclopropane (17), and cis-1-iminyl-2-keteniminylcyclopropane (19) to give products 16, 18, and 20, respectively, was conducted. Analysis of the active space MOs of TS(15-->16), TS(17-->18), and TS(19-->20) suggests that the 17 --> 18 and 19 --> 20 rearrangements are classically pericyclic, whereas the 15 --> 16 rearrangement is pseudopericyclic with two orbital disconnections-one involving the nitrogen lone-pair orbital and the other the carbonyl carbon of the ketene moiety. The novel TS(15-->16) was also found to have a highly planar, tight, geometry, whereas TS(17-->18) and TS(19-->20) were both shown to have the boat-shaped geometry expected for classically pericyclic [3,3] sigmatropic rearrangements.

The Vermedx Diabetes Information System reduces healthcare utilization.

Objective: To confirm the cost savings in a randomized clinical trial of the Vermedx Diabetes Information System (hereafter referred to as the Diabetes Information System [DIS]) in independently collected data using claims paid by a managed care insurer for patients with and without DIS participation.

Study Design: Longitudinal analysis of paid claims with concurrent and historical controls from October 2002 through October 2007.

Methods: Using locally weighted smoothing functions and linear regression analysis before and after commencement of the DIS, we compared the total claims paid per member per month for 153 patients using the DIS versus 870 control patients.

Secondary orbital effect in the electrocyclic ring closure of 7-Azahepta-1,2,4,6-tetraeneA CASSCF molecular orbital study.

Results of (10,9)CASSCF/6-31G* and B3LYP/6-31G* level calculations on the potential surface for the electrocyclic ring closure of E-7-azahepta-1,2,4,6-tetraene 3 to 1-aza-6-methylidenecyclohexa-2,4-diene ( 4) are reported, as well as parallel calculations on the electrocyclizations of hepta-1,2,4,6-tetraene 5, hexa-1,3,5-triene 7, Z and E-1-aza-1,3,5-hexatrienes 9 and 10, and Z-7-azahepta-1,2,4,6-tetraene 12 for purposes of careful comparison. The 3 --> 4 rearrangement has been studied computationally with density functional theory (DFT) by others, leading to disagreement over whether it is pseudopericyclic (de Lera, A. R.