Gold nanoparticles stabilized by phosphine-decorated polymer immobilized ionic liquids (AuNP@PPh2-PIILP) is an extremely efficient multiproduct selective catalyst for the sodium borohydride-mediated reduction of nitrobenzene giving N-phenylhydroxylamine, azoxybenzene, or aniline as the sole product under mild conditions and a very low catalyst loading. The use of a single nanoparticle-based catalyst for the partial and complete reduction of nitroarenes to afford three different products with exceptionally high selectivities is unprecedented. Under optimum conditions, thermodynamically unfavorable N-phenylhydroxylamine can be obtained as the sole product in near quantitative yield in water, whereas a change in reaction solvent to ethanol results in a dramatic switch in selectivity to afford azoxybenzene. The key to obtaining such a high selectivity for N-phenylhydroxylamine is the use of a nitrogen atmosphere at room temperature as reactions conducted under an inert atmosphere occur via the direct pathway and are essentially irreversible, while reactions in air afford significant amounts of azoxy-based products by virtue of competing condensation due to reversible formation of N-phenylhydroxylamine. Ultimately, aniline can also be obtained quantitatively and selectively by adjusting the reaction temperature and time accordingly. Introduction of PEG onto the polyionic liquid resulted in a dramatic improvement in catalyst efficiency such that N-phenylhydroxylamine could be obtained with a turnover number (TON) of 100 000 (turnover frequency (TOF) of 73 000 h–1, with >99% selectivity), azoxybenzene with a TON of 55 000 (TOF of 37 000 h–1 with 100% selectivity), and aniline with a TON of 500 000 (TOF of 62 500 h–1, with 100% selectivity). As the combination of ionic liquid and phosphine is required to achieve high activity and selectivity, further studies are currently underway to explore whether interfacial electronic effects influence adsorption and thereby selectivity and whether channeling of the substrate by the electrostatic potential around the AuNPs is responsible for the high activity. This is the first report of a AuNP-based system that can selectively reduce nitroarenes to either of two synthetically important intermediates as well as aniline and, in this regard, is an exciting discovery that will form the basis to develop a continuous flow process enabling facile scale-up.

SYNOPSIS The purpose of the present study was to compare the efficacy and safety of naproxen sodium (550 mg), acetaminophen (650 mg) and placebo in the treatment of muscle‐contraction, or tension headache. Six investigators participated in this randomized, double‐blind, 3‐way parallel study, in which 149 patients were entered. Each patient treated one episode of moderate‐to‐severe headache with the test medication. The intensity of the headache pain was recorded on 10 cm visual analogue scales (VASs) by patients for up to 12 hours after treatment with the study medication. In addition, the degree of pain relief (PR) was recorded in a similar manner. Mean pain intensities (Pls), percentage changes in mean pain intensities, pain intensity differences (PIDs) and the sum of these differences (SPIDs) were calculated. From the data collected in 124 patients eligible for efficacy analysis, naproxen sodium was shown to provide a significantly greater percentage change in mean PI compared to acetaminophen (p<0.01) or placebo (p<0.001). Mean PID and SPID scores also showed naproxen sodium to be significantly more effective in relieving pain compared to acetaminophen (p<0.02) or placebo (p<0.001). Mean pain relief scores and calculated total pain relief (TOTPAR) scores correlated well with the reduction in pain intensity. During the trial 13 patients reported side effects including nausea, dizziness and drowsiness. None of the side effects were considered clinically significant. The results from this study demonstrated naproxen sodium to be a well tolerated analgesic, which provided statistically significantly superior analgesia compared to acetaminophen or placebo in the treatment of muscle‐contraction or tension headaches.

Lateral skull cephalograms from 50 patients who subsequently had surgical correction of their Class III malocclusion were analysed using a complete linkage cluster analysis based on skull shape. Five subgroups Were identified and are described. All subjects had a degree of mandibular prognathism while only 14 per cent had maxillary retrognathism. An increased lower face height was found in 58 per cent.

This paper explores in patients with dialysis osteodystrophy the relationship between clinical features and histological, radiological, and biochemical findings. Eighty-five patients treated by hemodialysis for more than 6 months were studied. The following conclusions were drawn: 1) Bone pain in patients on regular hemodialysis is usually a symptom of developing osteomalacia but not of hyperparathyroidism or osteoporosis. 2) Many patients with histological osteomalacia and radiological features of osteomalacia, such as fractures or Looser zones, have no symptoms. 3)In dialysis patients, biochemical and radiological abnormalities are not a reliable means of predicting the presence of osteomalacia, but a raised serum alkaline phosphatase is a good indicator of the presence of osteitis fibrosa. For early detection of osteomalacia, bone biopsy in necessary. 4)A number of our dialysis patients develop an unusual form of osteomalacia characterized by absent or minimal histological osteitis fibrosa, a normal serum alkaline phosphatase, and a high incidence of myopathy and fractures.

No abstract