The reaction of 1,4-dimethoxybenzene and paraformaldehyde using AlBr(3) yields multiple-deprotected pillar[5]arenes. A1/B2 di-deprotected pillar[5]arene can be isolated by silica gel chromatography and washing procedures. The X-ray structure and polymerization of the A1/B2 di-deprotected pillar[5]arene are reported.

The complexation behavior of pillar[6]arene hosts towards a carbonium ion, tropylium tetrafluoroborate (T·BF4), and the formation of novel charge-transfer (CT) inclusion complexes are described. In contrast, smaller pillar[5]arenes and larger pillar[7]arenes cannot form such complexes due to the unsuitable cavity dimensions.

Background and purpose - Different radiographic classifications have been proposed for prediction of outcome in Perthes disease. We assessed whether the modified lateral pillar classification would provide more reliable interobserver agreement and prognostic value compared with the original lateral pillar classification and the Catterall classification. Patients and methods - 42 patients (38 bo...

A pillar[4]arene[1]quinone and a difunctionalized pillar[5]arene have been synthesized by partial oxidation.

Until quite recently, the Chinese pension system was an enterprise-based, pay-as-you-go, defined benefit scheme. In 1995, the decision was made to shift to a multi-pillar scheme that included a second funded defined contribution pillar. The transition is proving difficult. This article outlines an alternative second pillar that may make more sense for China, a pay-as-you-go notional defined con...

To construct a bridge as a crossing building on a very wide river it might not used one span only, therefor, in middle of the river it is needed pillar as support. The existing of the pillars will change velocity distribution, surface water and topography of sediment, especially when the pillar is located on the bend of the river where the very large hydraulic can be hepened. Therefore, this st...

BACKGROUND To evaluate the usefulness of the modified lateral pillar classification as a prognostic factor in Legg-Calvé-Perthes disease (LCPD). METHODS Thirty nine patients diagnosed with lateral pillar C in LCPD from May, 1977, to October, 2001 were reviewed, and their skeletal maturity was followed. The mean follow up duration was 12 years and 7 months (4 years, 6 months to 24 years, 9 mon...

We have synthesized a pillar[6]arene in high yield and a co-pillar[6]arene using chlorocyclohexane as a solvent.

The treatments for non-deficit forms of carpal tunnel syndrome (CTS) are corticoid infiltration and/or a nighttime immobilization brace. Surgical treatment, which includes sectioning the retinaculum of the flexors (retinaculotomy), is indicated in cases of resistance to conservative treatment in deficit forms or, more frequently, in acute forms. In minimally invasive techniques (endoscopy and m...

Room-and-pillar mining with pillar recovery has historically been associated with more than 25% of all ground fall fatalities in underground coal mines in the United States. The risk of ground falls during pillar recovery increases in multiple-seam mining conditions. The hazards associated with pillar recovery in multiple-seam mining include roof cutters, roof falls, rib rolls, coal outbursts, ...