Recent results and prospects for high p T physics at DØ

The European Physical Journal C - I present recent results from the DØ experiment using ≈ 50 pb–1 of data recorded at the center of mass energy of 1.96 TeV at the Fermilab...     

<Emphasis Type="Italic">N</Emphasis> = 1 Supersymmetric Sigma Model with Boundaries,I

 We study an N=1 two-dimensional non-linear sigma model with boundaries representing, e.g., a gauge fixed open string. We describe the full set of boundary conditions compatible with N=1 superconformal symmetry. The problem is analyzed in two different ways: by studying requirements for invariance of the action, and by studying the conserved supercurrent. We present the target space interpretation of these results, and identify the appearance of partially integrable almost product structures. Received: 27 November 2001 / Accepted: 16 August 2002 Published online: 19 December 2002 Acknowledgements. We are grateful to Ingemar Bengtsson and Andrea Cappelli for discussions and comments. MZ would like to thank the ITP, Stockholm University, where part of this work was carried out. UL acknowledges support in part by EU contract HPNR-CT-2000-0122 and by NFR grant 650-1998368. Communicated by R.H. Dijkgraaf     

A simple, highly regioselective, one-pot stereoselective synthesis of tertiary α-hydroxyesters: a tandem oxidation/benzilic ester rearrangement

This letter describes a simple, highly regioselective, stereoselective one-pot tandem oxidation/benzilic ester rearrangement protocol for the conversion of α-hydroxyketones to tertiary α-hydroxyesters.     

Recovery of polyols from flexible polyurethane foam by “split-phase” glycolysis: Glycol influence

Scrap of flexible polyurethane foams from slabstock manufacturing comprises about 10% of the total production, leading to not only an environmental problem but also an economic one. The general purpose of polyurethane chemical recycling is to recover a valuable constituent, the polyol. Among the processes suitable, glycolysis, and specially glycolysis in two phases seems to be the method that allows better quality products. In this study glycolysis of flexible polyurethane foams in “split phase” was conducted with different glycols, in order to study their activity and select a system to obtain the highest quality recovered polyol. Reaction kinetics and the products obtained were investigated. Times required to reach complete conversion, chemical properties of the polyol phase and its purity depended on the glycol employed. Diethylene glycol proved to be the most suitable glycol to obtain a high purity in the polyol phase.     

Stability-Indicating LC Determination of a New Antihypertensive,Olmesartan Medoxomil in Tablets

A stability-indicating liquid chromatographic method was developed and validated for quantitative determination of olmesartan medoxomil (OLM) in coated tablets in the presence of degradation products generated under stress conditions. An isocratic LC separation was performed using a Phenomenex RP-18 column using a mobile phase consisting of water:triethylamine:acetonitrile (60:0.3:40 v/v/v, pH adjusted to 6.3 with phosphoric acid). The flow rate was 1.2 mL min⁻¹ and the detection was achieved with a photodiode array detector set at 257 nm. The response was linear over a range of 10.0 to 30.0 μg mL⁻¹ (r = 0.9999). The specificity and stability-indicating capability of the method was verified subjecting the reference substance and drug product to hydrolytic, oxidative, photolytic, and thermal stress conditions. The method showed a good and consistent recovery (100.2%) with low intra- and inter-day relative standard deviation (RSD) (≤1.0%). A considerable degradation occurred in all stress conditions and the degradation product was well resolved from the main peak. There was no interference of the excipients in the determination of the active pharmaceutical ingredient. Thus, the proposed method was found to be stability-indicating and can be used for routine analysis for quantitative determination of OLM in coated tablets without the interference of major degradation products.

     

The Cauchy numbers

We study many properties of Cauchy numbers in terms of generating functions and Riordan arrays and find several new identities relating these numbers with Stirling, Bernoulli and harmonic numbers. We also reconsider the Laplace summation formula showing some applications involving the Cauchy numbers.     

Effects of Massage Therapy and Occlusal Splint Usage on Quality of Life and Pain in Individuals with Sleep Bruxism: A Randomized Controlled Trial

Purpose: The aim of the present study was to investigate the effects of massage therapy on the masticatory muscles and occlusal splint usage on quality of life and pain in individuals with sleep bruxism. Method: A randomized, controlled, blinded, clinical trial was conducted involving 78 volunteers aged 18 to 40 years with sleep bruxism. Quality of life and pain assessments were performed. Results: Significant differences (p < 0.05) were found on the physical functioning, general health state, vitality, role emotional and mental health subscales. A large effect size was found for all treatment protocols with regard to pain. The largest effect was found in the combined treatment group. Conclusions: The findings of the present study reveal that the occlusal splint usage alone led to improvements in components of quality of life among individuals with sleep bruxism. Moreover, both treatments (occlusal splint usage and massage therapy on the masticatory muscles) led to a reduction in pain.     

Hydration of α-pinene catalyzed by acid clays

The hydration reaction of α-pinene in the presence of natural clays treated with monochloroacetic acid as catalyst to obtain oxygenated compounds was studied. Catalysts were characterized using X-ray diffraction, differential thermal analysis, programmed thermal desorption of adsorbed pyridine, and infrared spectroscopic analysis of adsorbed pyridine to determine Brønsted and Lewis acid sites. Catalytic tests revealed that treatment of the natural clay with the acid improved the catalytic activity and the selectivity toward oxygenated products by increasing the acidity of the catalyst. The selectivity toward oxygenated compounds increased with the augment of the α-pinene conversion because of greater contact between water molecules with the remaining α-pinene molecules. The natural clay without treatment produced compounds resulting from α-pinene isomerization, whereas the treated clays produced alcohols and other products in addition to isomerization compounds. After a certain time, the α-terpineol was isomerized into cineols. Studies of the reusability of the JAL catalyst were performed (clay treated with monochloroacetic acid). As the number of reuses increased, the percent conversion decreased; however, the selectivity toward oxygenated compounds increased.