On the rate of convergence to the normal law for solutions of the Burgers equation with singular initial data

We study the scaling limit of random fields which are the solutions of a nonlinear partial differential equation known as the Burgers equation, under stochastic initial condition. These are assumed to be a Gaussian process with long-range dependence. We present some results on the rate of convergence to the normal law.     

Processes governed by signed measures connected with third-order “heat-type” equations

Dipartamento di Statistica, Probabilita e Statistiche Applicate, University of Rome, La Sapienza, Italy. Published in Litovskii Matematicheskii Sbornik (Lietuvos Matematikos Rinkinys), Vol. 31, No. 2, pp. 323–336, April–June, 1991.     

Determinazione per bromurazione dell'acido p-aminosalicilico nelle urine

Résumé Le dosage de l'acide p-aminosalicylique (PAS) dans l'urine a lieu par extraction avec l'éther àh 2,5, évaporation de l'éther, bromuration par le mélange bromure-bromate et titrage en retour de l'excès de brome par iodométrie. L'urine exempte de PAS ne se laisse pas enlever par l'éther de substance consommant du brome.On a étudié le comportement du dérivé N-acétylé du PAS et du dérivé O-N-diacétylé le premier de ces composés se comporte par bromuration comme l'acide non acétylé lui-même et consomme 3 mol. de brome. Le dérivé diacétylé ne subit aucune hydrolyse et ne consomme pas de brome. Il se recommande pour opérer le dosage après saponification acide. La méthode décrite donne de bons résultats en présence d'environ 0,5 mg PAS par ml d'urine.

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Summary The determination of p-aminosalicylic acid (PAS) in urine is accomplished by extraction with ether ath = 2,5, distillation of the ether, bromination by means of KBrO₃-KBr, and back-titration of the excess bromine iodometrically.No bromine-consuming materials are extracted by ether from urine which is free of PAS.The behavior of the N-acetyl derivative of PAS and of the O-N-diacetyl derivative was investigated; the former behave like the non-acetylated acid toward bromination and consumes 3 molecules of bromine. The diacetyl derivative undergoes no hydrolytic splitting and consumes no bromine. It is best to make the determination after acid saponification.The method described here gives good results in the presence of about 0,5 mg PAS per ml of urine.

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Zusammenfassung Die Bestimmung der p-Aminosalicylsäure im Harn erfolgt durch Extraktion mit Äther beih 2,5, Abdestillation des Äthers, Bromierung mittels Kalium-Bromid-Bromat und Rücktitration des Bromüberschusses auf jodometrischem Wege.Harn, der frei ist von p-Aminosalicylsäure, werden mittels Äther keine Brom verbrauchenden Stoffe entzogen.Das Verhalten des N-Acetylderivates der p-Aminosalicylsäure und des O-N-Diacetylderivates wurde untersucht; erstere Verbindung verhält sich bei der Bromierung wie die nicht acetylierte Säure selbst und verbraucht 3 Moleküle Brom. Das Diacetylderivat unterliegt keiner hydrolytischen Spaltung und verbraucht kein Brom. Es empfiehlt sich, die Bestimmung nach saurer Verseifung durchzuführen.Die beschriebene Methode gibt gute Resultate bei Anwesenheit von etwa 0,5 mg p-Aminosalicylsäure pro ml Harn.

     

Validation of a new HPLC‐UV method for determination of the antibiotic linezolid in human plasma and in bronchoalveolar lavage

A rapid and selective HPLC‐UV method was developed for the quantification of linezolid (LNZ) in human plasma and bronchoalveolar lavage (BAL) at the concentrations associated with therapy. Plasma samples were extracted by solid‐phase extraction followed by evaporation to dryness and reconstitution in mobile phase solution. The chromatographic separation was carried out on a C₁₈ column with an isocratic mobile phase consisting of dihydrogen phosphate buffer 50 mm (pH 3.5) and acetonitrile (60:40 v/v). The detection was performed using a photodiode array. Under these conditions, a single chromatographic run could be completed within 12 min. The method was validated by estimating the precision and the accuracy for inter‐ and intra‐day analysis in the concentration range of 25–25600 ng/mL. The method was linear over the investigated range with all the correlation coefficients R > 0.999. The intra‐ and inter‐day precision was within 8.90% and the accuracy ranged from ?4.76 to +5.20%. This rapid and sensitive method was fully validated and could be applied to pharmacokinetic study for the determination of LNZ levels in human plasma and BAL samples. Copyright © 2013 John Wiley & Sons, Ltd.     

Lipase-Catalyzed Regio- and Stereoselective Acylation of Hydroxy Groups in Steroid Side Chains

 Lipase from Pseudomonas cepacia (PCL) catalyzes the regio- and stereoselective acylation of primary and secondary hydroxy groups in steroid side chains under irreversible transesterification conditions with vinyl acetate in organic solvents.     

A high‐throughput bioanalytical platform using automated infusion for tandem mass spectrometric method optimization and its application in a metabolic stability screen

Liquid chromatography/tandem mass spectrometry (LC/MS/MS) is the bioanalytical method of choice to support plate‐based, in vitro early ADME (Absorption, Distribution, Metabolism and Excretion) screens such as metabolic stability (Metstab) assessment. MS/MS method optimization has historically been the bottleneck in this environment, where samples from thousands of discrete compounds are analyzed on a monthly basis, mainly due to the lack of a high‐quality commercially available platform to handle the necessary MS/MS method optimization steps for sample analysis by selected reaction monitoring (SRM) on triple quadrupole mass spectrometers. To address this challenge, we recently developed a highly automated bioanalytical platform by successfully integrating QuickQuan? 2.0, a unique high‐throughput solution featuring MS/MS method optimization by automated infusion, with a customized in‐house software tool in support of a Metstab screen. In this platform, a dual‐column setup running parallel chromatography was also implemented to reduce the bioanalytical cycle time for LC/MS/MS sample analysis. A set of 45 validation compounds was used to demonstrate the speed, quality and reproducibility of MS/MS method optimization, sample analysis, and data processing using this automated platform. Metstab results for the validation compounds in microsomes from multiple species (human, rat, mouse) showed good consistency within each batch, and also between batches conducted on different days. We have achieved and maintained a monthly throughput of 1300 compound assays representing 500 discrete compounds per instrument per month on this platform, and it has been used to generate metabolic stability data for more than 25 000 compounds to date with an overall success rate of more than 95%. Copyright © 2009 John Wiley & Sons, Ltd.     

Nonexistence of weak solutions for some degenerate elliptic and parabolic problems on $ {\Bbb R}^n $

No Abstract       

Non-Porous versus Mesoporous Siliceous Materials for CO2 Capture

In this study, the adsorption properties of a Stöber silica-based material towards CO₂ were evaluated for the first time. The use of Stöber silica as support is interesting for real technological applications mainly due to economic factors. Furthermore, a direct comparison between the non porous Stöber sample with an ordered porous material (based on MCM-41 silica) allowed to evaluate the effect of the porosity on the CO₂ adsorption properties. In order to make silica materials reactive towards CO₂, they were functionalized by introducing amino groups via grafting of 3-[2-(2-aminoethyl)aminoethyl]aminopropyltrimethoxysilane. After a qualitative study of the CO₂ adsorption, the quantitative determination of CO₂ adsorption capacity at 35 °C revealed that the mesoporous material is more efficient compared to the Stöber-based one (adsorption capacity values of 0.49 and 0.58 mol/kg for Stöber-based and mesoporous samples). However, since the difference in the adsorption capacity is only about 15 % and the Stöber-based sample is considerably cheaper, the non-porous sample should be considered as a favourable adsorbent material for CO₂ capture applications.