Working group report: Flavor physics and model building

This is the report of flavor physics and model building working group at WHEPP-9. While activites in flavor physics have been mainly focused on B-physics, those in model building have been primarily devoted to neutrino physics. We present summary of working group discussions carried out during the workshop in the above fields, and also briefly review the progress made in some projects subsequently.     

Heterocyclic inflammation inhibitors

Non steroidal anti-inflammatory drugs are the most widely used medicines for relief of pain. These drugs have some side effects, particularly toxicity in the gastrointestinal tract and kidneys. Various approaches have been used for obtaining safer anti-inflammatory drugs. In this review we have summarized the recent developments in the following areas; (i) mode of action of NSAIDs (ii) Role of COX-1 & COX-2 in inflammation, (iii) Different approaches used to improve gastric tolerance i.e. chemical manipulation, formulation & co-administration, development of non specific (COX-1 & COX-2 inhibitors) and specific (COX-2 inhibitors) inflammation inhibitors, and development of inflammation inhibitors having a mode of action other than COX-1 & COX-2 inhibition. We have also focused on the safety of COX-2 inhibitors and the synthesis of heterocyclic compounds and their role as inflammation inhibitors.     

Diaminodithioether complexes of nickel(II) and palladium(II): A unique case of dealkylation of S,S′-thioether

Summary Nickel(II) and palladium(II) complexes of the 1,3-di(o-aminophenylthio) propane (H₂L¹) and 1,2-di(o-aminophenylthio)xylene (H₂L²) ligands have been prepared and characterized. The hydrobromide salt of H₂L¹ gave a 12 ligand-metal complex of Pd^II, whereas free H₂L¹ formed the usual 1:1 species. The reaction of Na₂PdCl₄ with H₂L² resulted in S,S-dealkylation of the ligand and formation of a mononuclear complex of the corresponding thiol, i.e. 2-aminobenzenethiol. NiCl₂, NiBr₂ and Ni(ClO₄)₂ did not react directly with H₂L². Ni^II is a fairly hard ion and therefore does not coordinate to the soft thioether moiety in H₂L² in the absence of soft anions which symbiotically motivate Ni^II to act as a soft acceptor. It thus does not react with H₂L² in the presence of hard ions such as Cl^–, Br^- and ClO ₄ ^– , but, the in situ reaction of the constituents produced the tetrahedral Ni^II complex, contrary to earlier reports of similar types of octahedral species.     

Development of a pH titration method for the simultaneous determination of uranium,nitrate and free-acid in the feed solution of the sol-gel process of nuclear fuel fabrication

pH titration curves generated by slow addition of alkali to solutions containing varying concentrations of uranyl nitrate and nitric acid were studied using an autotitrator linked to a personal computer. A procedure with multiple choice of equations has been developed for the estimation of free acid, nitrate and uranium in pure uranyl nitrate solution by a single titration. The technique provides a simple single-step method with required accuracy and precision for the simultaneous estimation of the three quantities in the uranyl nitrate feed solution of the sol-gel process for making UO₃ microspheres. The relative standard deviations in the determination of uranium and nitrate were ±0.82% and ±1.52%, respectively, in 15 determinations.     

A new algorithm for minimizing convex functions over convex sets

Let be a convex set for which there is an oracle with the following property. Given any pointz∈ℝ ⁿ the oracle returns a “Yes” ifz∈S; whereas ifz∉S then the oracle returns a “No” together with a hyperplane that separatesz fromS. The feasibility problem is the problem of finding a point inS; the convex optimization problem is the problem of minimizing a convex function overS. We present a new algorithm for the feasibility problem. The notion of a volumetric center of a polytope and a related ellipsoid of maximum volume inscribable in the polytope are central to the algorithm. Our algorithm has a significantly better global convergence rate and time complexity than the ellipsoid algorithm. The algorithm for the feasibility problem easily adapts to the convex optimization problem.     

An Einstein-Gödel universe

The metric for the standard static Einstein model of the universe can be expressed in coordinates for which a congruence of spacelike world lines of the model will be twisting. A method of shifting the twist has been devised by which the twist on spacelike world lines is shifted onto the timelike world lines. The model universe then becomes Gödel's model. A combined Einstein-Gödel model containing a parameter is obtained. Switching from +1 to –1 will effect the shift of twist in the world lines and lead from the Einstein model to the Gödel model.     

Heat transfer errors in quantitative differential thermal analysis

A DTA apparatus has been built to examine some of the errors neglected in present quantitative DTA. The heat transfer characteristics within DTA systems were found to limit in situ measurements of powder thermal conductivity. It was also demonstrated that the negligence of heat lost to the DTA block from the sample cell during an exothermic reaction and heat gained from the DTA block by the sample cell during endothermic reactions lead to large errors in quantitative estimations. A modified double differential thermocouple DTA was designed to take these heat losses into account. The apparatus was calibrated with CaCO₃ and kaolinite endotherms and the kaolinite exotherm and tested on the SrCO₃ rhombic trigonal inversion endotherm. The result was found to be in good agreement with accepted literature values.

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Zusammenfassung Ein DTA-Apparatur wurde gebaut um einige in der gegenwärtig üblichen quantitativen DTA vernachlässigte Fehler zu prüfen. Es wurde gefunden, daß die Wärmeübertragungscharakteristika in DTA-Systemen die in situ Messungen der Wärmeleitfähigkeit von Pulvern begrenzen. Es wurde ebenfalls gezeigt, daß die Vernachlässigung von Wärmeverlusten der Probezelle an den DTA-Block bei exothermen Reaktionen und vom Wärmegewinn der Probezelle vom DTA-Block bei endothermen Reaktionen zu bedeutenden Fehlern in den quantitativen Bestimmungen führt. Ein DTA-Gerät mit doppeltem Differentialthermoelement wurde entworfen um diese Wärmeverluste zu berücksichtigen. Der Apparat wurde mittels der endothermen Reaktionen von CaCO₃ und Kaolinit, bzw. mittels der exothermen Reaktion von Kaolinit geeicht und an der Inversion von rhombischem zu trigonalem SrCO₃ erprobt.

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Résumé On a réalisé un appareil ATD pour étudier certaines erreurs négligées jusqu'à présent en ATD quantitative. On a trouvé ainsi que les caractéristiques du transfert de chaleur limitent la mesure in situ de la conductivité thermique des poudres. On montre également que le fait de négliger les échanges de chaleur entre la cellule renfermant l'échantillon et le bloc ATD (pertes ou gains de chaleur suivant que les réactions sont exothermiques ou endothermiques) conduit à des erreurs considérables dans les dosages. Un double thermocouple différentiel a été conçu pour tenir compte de ces pertes. L'étalonnage de l'appareil a été ré alisé à l'aide des réactions endothermiques de CaCO₃ et de la kaolinite et contrôlé avec la transition endothermique de SrCO₃ (rhomboédrique-trigonal).

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DTA , DTA. , DTA . , , DTA DTA . , . CaCO₃ SrCO₃.

     

Ensuring robustness in the quality of antibiotic susceptibility test discs for four novel antibiotics

Antibiotic susceptibility test (AST) discs are used as an in-vitro diagnostic tool to select the appropriate antibiotic to treat an infection. Generally, the concentration of the drug loaded on to the AST discs is measured by studying its activity against quality control organisms. This methodology has several limitations—it is time consuming, requires trained manpower, has a wider acceptance criteria of zone of inhibitions—causing ambiguity in judging smaller variations in drug concentration. To overcome these issues, we have developed and validated high-performance liquid chromatographic (HPLC) methods for the determination of strength of AST discs for in-house researched antibiotics, namely Levonadifloxacin/WCK 771, Nafithromycin/WCK 4873, Cefepime-Tazobactam/WCK 4282, and Cefepime-Zidebactam/WCK 5222. The drugs were extracted from the AST discs using an appropriate solvent. The developed methods are simple, accurate, precise, reproducible, rugged, and robust. They are efficient in terms of time, and can be easily conducted in a quality control laboratory during release as well as stability evaluation of AST disc. Application of HPLC methods for the determination of strength of AST discs ensures flawless quality and, consequently, a better selection of drugs to treat bacterial infections in clinics.     

MASS SPECTROMETRIC FRAGMENTATION OF UNSYMMETRICALLY SUBSTITUTED METHYLPHOSPHONATE DIESTERS

Abstract

A series of structurally related unsymmetrically substituted methylphosphonate diesters have been synthesised and subjected to electron impact (El) mass spectral studies. These studies though aimed at total identification of the compounds, resulted in certain interesting observations and hence are being reported. In order to confirm the observations under electron impact and to support the mechanism of fragmentation we have also performed MSNS experiments in both daughter ion and parent ion modes.