Emission modeling at toll plaza under mixed traffic condition using simulation.

Mixed traffic conditions, i.e., the presence of different vehicle classes in a toll lane, causes congestion, leading to extra delay and emissions. The determination of the emission levels in the field is tedious process and thus there is need to look over it. Further, the dynamic toll pricing schemes are well established in developed countries to mitigate the congestion, but its application in developing countries is not observed so far. Hence, an attempt is made in the present study to establish the dynamic toll rates based on emission at toll plazas operating under mixed traffic conditions. The sensitivity analysis is carried out by changing the traffic composition and the approach volume in simulation. After that, the traffic composition and approach volume-based emission estimation equations are developed that can be used to predict the emissions easily in the field. The methodology finally moves towards the development of emission-based toll rates (EBTR).

Mutations and structural variations in Catechol-O-methyltransferase gene of patients exhibiting chronic persistent surgical pain. / Mutaciones y variaciones estructurales en el gen catecol-O-metiltransferasa de los pacientes que exhiben dolor quirúrgico persistente crónico.

OBJECTIVES: Mutations in the exon 4 of the COMT gene are associated with chronic persistent surgical pain (CPSP). Especially COMT mutated allele G472A (Val158Met) associated with CPSP patients is reported in different ethnic population. The purpose of this study is to evaluate the prevalence of genetic mutations and structural variations in exon 4 of COMT that can be related to the appearance of CPSP in patients under sternotomy. MATERIALS AND METHODS: One hundred patients with American Society of Anesthesiologists (ASA) physical status grades i, ii and iii, who underwent sternotomy procedures, were selected to assess the development and magnitude of the CPSP evaluated with pain questionaries' at the end of three months after surgery. This was correlated with COMT allele presence. The exon 4 of COMT gene (that contains the G472A allele) was studied. The polymerase chain reaction (PCR) products were sequenced and mutated sequences were deposited in GenBank®. The structural analysis of COMT was performed using ProCheck® and distortions of three-dimensional tertiary structural orientation was evaluated with root-mean-square deviation (RMSD) score. RESULTS: Genetic analysis carried out through PCR showed 220 bp amplicons. The 25% of patients with CPSP showed a Numeric Rating Scale (NRS) > 4 pain score. The 20% of these patients have known Val158Met mutation, 5% of patients showed novel mutations c.382C>G, c.383G>C, p.(Arg128Ala). The mutations in COMT gene contributed major structural variations in COMT leading to the formation of inactive COMT that correlates with CPSP. CONCLUSION: The results of the present study showed that both novel and previously reported mutations in COMT gene has strong association with CPSP.

In Staphylococcus aureus the regulation of pyruvate kinase activity by serine/threonine protein kinase favors biofilm formation.

Staphylococcus aureus, a natural inhabitant of nasopharyngeal tract, survives mainly as biofilms. Previously we have observed that S. aureus ATCC 12600 grown under anaerobic conditions exhibited high rate of biofilm formation and L-lactate dehydrogenase activity. Thus, the concentration of pyruvate plays a critical role in S. aureus, which is primarily catalyzed by pyruvate kinase (PK). Analyses of the PK gene sequence (JN645815) revealed presence of PknB site in PK gene indicating that phosphorylation may be influencing the functioning of PK. To establish this hypothesis the pure enzymes of S. aureus ATCC 12600 were obtained by expressing these genes in PK 1 and PV 1 (JN695616) clones and passing the cytosolic fractions through nickel metal chelate column. The molecular weights of pure recombinant PK and PknB are 63 and 73 kDa, respectively. The enzyme kinetics of pure PK showed K M of 0.69 ± 0.02 µM, while the K M of PknB for stpks (stpks = NLCNIPCSALLSSDITASVNCAK) substrate was 0.720 ± 0.08 mM and 0.380 ± 0.07 mM for autophosphorylation. The phosphorylated PK exhibited 40 % reduced activity (PK = 0.2 ± 0.015 µM NADH/min/ml to P-PK = 0.12 ± 0.01 µM NADH/min/ml). Elevated synthesis of pyruvate kinase was observed in S. aureus ATCC 12600 grown in anaerobic conditions suggesting that the formed pyruvate is more utilized in the synthesis phase, supporting increased rate of biofilm formation.

Comparative Structural and Functional Analysis of Staphylococcus aureus Glucokinase with other Bacterial Glucokinases.

Glucokinase is classified in bacteria based upon having ATP binding site and 'repressor/open reading frames of unknown function/sugar kinases' motif, the sequence of glucokinase gene (JN645812) of Staphylococcus aureus ATCC12600 showed presence of ATP binding site and 'repressor/open reading frames of unknown function/sugar kinases' motif. We have earlier observed glucokinase of S. aureus has higher affinity towards the substrate compared to other bacterial glucokinase and under anaerobic condition with increased glucose concentration S. aureus exhibited higher rate of biofilm formation. To establish this, 3D structure of glucokinase was built using homology modeling method, the PROCHECK and ProSA-Web analysis indicated this built glucokinase structure was close to the crystal structure. This structure was superimposed with different bacterial glucokinase structures and from the root-mean-square deviation values, it is concluded that S. aureus glucokinase exhibited very close homology with Enterococcus faecalis and Clostridium difficle while with other bacteria it showed high degree of variations both in domain and nondomain regions. Glucose docking results indicated -12.3697 kcal/mol for S. aureus glucokinase compared with other bacterial glucokinase suggesting higher affinity of glucose which correlates with enzyme kinetics and higher rate of biofilm formation.

Design and synthesis of quinazolinone derivatives as anti-inflammatory agents: pharmacophore modeling and 3D QSAR studies.

A series of 36 novel substituted quinazolinone derivatives were synthesized and evaluated for their antiinflammatory activity by carrageenan induced paw inflammation model. The ability of these compounds to inhibit cyclooxygenase (COX-1 and 2) enzyme has been determined in-vitro; the results indicated that quinazolinone derivatives were selective towards COX-2 rather than COX-1. Among the quinazolinone derivatives tested, compound 32 showed better inhibition against COX-2 when compared with Celecoxib. Pharmacophore modeling and 3D QSAR studies were performed in order to elucidate structural insights for the anti-inflammatory activity.