Large N and Bosonization in Three Dimensions

Bosonization is normally thought of as a purely two-dimensional phenomenon, and generic field theories with fermions in D>2 are not expected be describable by local bosonic actions, except in some special cases. We point out that 3D SU(N) gauge theories on R^{1,1} x S^{1}_{L} with adjoint fermions can be bosonized in the large N limit. The key feature of such theories is that they enjoy large N volume independence for arbitrary circle size L. A consequence of this is a large N equivalence between these 3D gauge theories and certain 2D gauge theories, which matches a set of correlation functions in the 3D theories to corresponding observables in the 2D theories. As an example, we focus on a 3D SU(N) gauge theory with one flavor of adjoint Majorana fermions and derive the large-N equivalent 2D gauge theory. The extra dimension is encoded in the color degrees of freedom of the 2D theory. We then apply the technique of non-Abelian bosonization to the 2D theory to obtain an equivalent local theory written purely in terms of bosonic variables. Hence the bosonized version of the large N three-dimensional theory turns out to live in two dimensions.Comment: 30 pages, 2 tables. v2 minor revisions, references adde

Analytical Investigations of Toxic p-Phenylenediamine (PPD) Levels in Clinical Urine Samples with Special Focus on MALDI-MS/MS

Para-phenylenediamine (PPD) is a common chromophoric ingredient in oxidative hair-dyes. In some African countries like Sudan, Egypt and Morocco but also in India this chemical is used alone or in combination with colouring extracts like Henna for dyeing of the hair or the skin. Excessive dermal exposure to PPD mainly leads to the N-mono- and N,N′-diacetylated products (MAPPD, DAPPD) by N-acetyltransferase 1 and 2 (NAT1 and 2) catalyzed reactions. Metabolites and PPD are mainly excreted via renal clearance. Despite a low risk of intoxication when used in due form, there are numerous cases of acute intoxication in those countries every year. At the ENT Hospital - Khartoum (Sudan) alone more than 300 cases are reported every year (∼10% fatal), mostly caused by either an accidental or intended (suicidal) high systemic exposure to pure PPD. Intoxication leads to a severe clinical syndrome including laryngeal edema, rhabdomyolysis and subsequent renal failure, neurotoxicity and acute toxic hepatitis. To date, there is no defined clinical treatment or antidote available and treatment is largely supportive. Herein, we show the development of a quick on-site identification assay to facilitate differential diagnosis in the clinic and, more importantly, the implementation of an advanced analytical platform for future in-depth investigations of PPD intoxication and metabolism is described. The current work shows a sensitive (∼25 µM) wet chemistry assay, a validated MALDI-MS/MS and HPLC-UV assay for the determination of PPD and its metabolites in human urine. We show the feasibility of the methods for measuring PPD over a range of 50–1000 µM. The validation criteria included linearity, lower limit of quantification (LLOQ), accuracy and precision, recovery and stability. Finally, PPD concentrations were determined in clinical urine samples of cases of acute intoxication and the applied technique was expanded to identify MAPPD and DAPPD in the identical samples

A Rare Sequela of Constriction Band Syndrome: Case Report.

The patient in this case report is a 19-year-old man who presented with left foot cauliflower lesion. He complained of an inability to wear proper shoes, in addition to an unpleasant appearance of his foot. The lesion was present since his birth. Based on history and physical examination, the top 2 differential diagnoses at this stage were pediatric neurofibroma and constriction band syndrome (CBS). Laboratory investigations and x-ray were ordered for the patient. X-ray showed absence of most of the phalanges of the first, second, and third toes, with swelling of the overlying soft tissues of the foot. CBS was confirmed. Excision of the lesion was done along with skin graft applied on the area. Biopsy showed skin with dermal fibrosis and extensive adipose tissue infiltration without any sign of atypia or malignancy. The patient was discharged with regular follow-up appointments

Mass spectrometry of large molecules I Tandem mass spectrometry

In dit rapport worden de principes behandeld van de moderne massa-spectrometrische meetmethoden, met name de tandem massaspectrometrie. Tevens worden enige toepassingen van de tandem massaspectrometrie evaluerend besproken.Abstract not availableRIV

Mass spectrometry of large molecules. II The mass barrier: To be shifted?

Binnen en buiten het RIVM bestaat er een grote vraag naar de massaspectrometrische structuuranalyse van biopolymeren en met name naar de massaspectrometrische bepaling van de primaire structuur van proteinen. In rapport 638720001 werd vermeld dat uit de praktijk is gebleken dat de directe massaspectrometrische structuuranalyse van zeer grote moleculen (molmassa > 3000 daltons) (nog) niet mogelijk is. Wij behandelen in dit rapport de oorzaken van dit gelimiteerd massabereik. Het zal blijken dat een eventuele ontwikkeling van de directe massaspectrometrische structuuranalyse van zeer grote moleculen moeilijker zal zijn dan tot nu toe werd aangenomen. Een van de kernproblemen is dat grote moleculen kinetisch stabiel zijn t.o.v. de structuurkarakteristieke ketenfragmentaties; zulke moleculen zullen overwegend kleine periferische atomen of groepen afsplitsen. Een ander probleem is gelegen in het grote aantal laag-frequente trillingen waarin veel energie opgeslagen kan worden. Omdat grote eiwitten specifiek biochemisch afgebroken kunnen worden tot fragmenten met molmassa < 3000 lijkt de conclusie gewettigd dat uitbreiding van het massabereik niet kosten-efficient zal zijn.Abstract not availableRIV

Pilot FAB investigations with the mass spectrometer

Eerste orienterende metingen met fast atom bombardment (FAB) ionisatietechniek zijn uitgevoerd. De techniek werd toegepast bij de analyse van korte-keten polypeptiden (n=2-5), cyclosporine, NADP en microperoxidase. Onderzocht werd de invloed van de aard van de matrix (glycerol, thioglycerol) op het rendement van de ionisatie in relatie tot meer algemene stofeigenschappen. Thioglycerol bleek bij basische verbindingen te leiden tot een betere gevoeligheid. Analyses werden uitgevoerd bij zowel laag (R-800) als hoogoplossend vermogen (R=12.000 met een oplossend vermogen van 12.000) werd de molmassa van cyclosporine (MW 1201) bepaald met een nauwkeurigheid van +/- 0.008 daltons.Abstract not availableRIV