Correlation between Fluorimetric and Microbiological Methods for Determination of Cephalexin in Urine and Serum

Peer Reviewe

GTI-space : the space of generalized topological indices

A new extension of the generalized topological indices (GTI) approach is carried out torepresent 'simple' and 'composite' topological indices (TIs) in an unified way. Thisapproach defines a GTI-space from which both simple and composite TIs represent particular subspaces. Accordingly, simple TIs such as Wiener, Balaban, Zagreb, Harary and Randićconnectivity indices are expressed by means of the same GTI representation introduced for composite TIs such as hyper-Wiener, molecular topological index (MTI), Gutman index andreverse MTI. Using GTI-space approach we easily identify mathematical relations between some composite and simple indices, such as the relationship between hyper-Wiener and Wiener index and the relation between MTI and first Zagreb index. The relation of the GTI space with the sub-structural cluster expansion of property/activity is also analysed and some routes for the applications of this approach to QSPR/QSAR are also given

Sharp bounds and normalization of Wiener-type indices

10.1371/journal.pone.0078448PLoS ONE811-POLN

Fazno modelovanje dinamike rasta imobilisanih ćelija kvasca u Ca-alginatnim nosačima

A phase-field model was formulated to describe yeast cell growth within the Ca-alginate microbead during air-lift bioreactor cultivation. Model development was based on experimentally obtained data for intra-bead yeast cell volume fraction profile after reaching the equilibrium state, as well as, total yeast cell volume fraction per microbead and microbead volume as functions of time. Relatively uniform cell concentration in the microbead, experimentally obtained, indicated microenvironmental restriction effects due to deformation and disintegration of previously swollen alginate hydrogel, while internal nutrient diffusion limitation could be neglected in the case of alginate microbeads used in this study. Microbead with growing yeast cells is treated as two phase system. One phase represents the cell agglomerates, while the other is the alginate hydrogel matrices. The interactions between phases are modeled using the Langevin class, non-conservative phase-field model. Such class of models is suitable for considering the growth of small domains of one phase as nucleation. Besides giving useful insights into the dynamics of restrictive cell growth within the Ca-alginate microbead, the model can be used as a tool to design/optimize the performance of microbead and studying the microenvironmental restrictive mechanism action on the cell growth. .Fazni model je formulisan da opiše rast ćelija kvasaca unutar Ca-alginatnih nosača za vreme perioda kultivacije u air-lift bioreaktoru. Model je razvijen na osnovu prikupljenih eksperimentalnih podataka za profil yapreminskog udela ćelija unutar nosača nakon postizanja stacionarnog stanja, za yapreminski udeo ćelija po nosaču u funkciji vremena i za promenu zapremine nosača u toku vremena. Relativno uniformna koncentracija ćelija, eksperimentalno primećena, unutar Ca-alginatnih nosača ukazuje na postojanje restriktivnih efekata sredine koji limitiraju rast ćelija, kao što su deformisanje i razgradnja matrice nosača. Otpori difuziji nutrenata kroz nosač se mogu zanemariti. Mironosač sa imobilisanim ćelijama koje rastu se može tretirati kao dvo-fazni sistem. Jednu fazu pretstavljaju aglomerati ćelija, a drugu matrica Ca-alginatnog hidrogela. Interakcije izmedju faza su modelovane koristeći Lanževinovu klasu ne konzervativnih faznih modela. Ova klasa modela je pogodna za razmatranje rasta malih domena jedne faze u toku procesa nukleacije. S obziromda daje koristan uvid u dinamiku restriktivnog rasta ćelija unutar Ca-alginatnih nosača, ovaj model može biti korišćen kao sredstvo za dizajniranje/optimizaciju osobina mikronosača i proučavanje mehanizama restriktivnog dejstva mikrookoline ćelija unutar nosača na dinamiku rasta ćelija.

Mycopopulations of grain and flour of wheat, corn and buckwheat

According to the nutritive characteristics, whole grain flour is a high quality product, due to its high vitamin, mineral, and dietary fiber content. However, the cereal grains are susceptible to the series of contamination during the ripening, harvesting, processing and storage. The aim of this work was to determine mold presence in grains and flour of wheat, corn and buckwheat. The determination of total number and identification of isolated genera and species of molds were the subject of this research. All samples were contaminated with the molds. The total number of molds per 100 cereal grains was between 60 cfu (wheat) and 120 cfu (buckwheat). The total number of molds in the samples of flour ranged from 6.0x101 cfu/g in white wheat flour to 5.0 x102 cfu/g in buckwheat whole grain flour (DG18 medium). Eight fungal genera (Alternaria, Aspergillus, Cladosporium, Chrysonilia, Fusarium, Penicillium, Rhizopus and Scopulariopsis) and fifteen species were isolated. The largest number of species of molds was isolated from the genus Aspergillus. About 66.7% of isolated fungi belonged to potentially toxigenic species. The results pointed out the necessity of grain surface treatment, preceding the milling of grains in wheat, corn and whole grain buckwheat flour production