Propose Modifications to the Device for Preheating Tube Billets

Import 26/06/2013Úprava zařízení pro předehřev trubkových předvalkůPropose preheating device for mill tubes361 - Katedra energetikyvelmi dobř

Istraživanje vezanja kofeina na albumin iz ljudskoga seruma

Binding of caffeine to human serum albumin (HSA) was investigated with the aim of describing the binding parameters of the interaction. It was found that the results obtained by fluorescence spectroscopy are influenced by the non-negligible artifact, known as the inner filter effect due to the absorption of caffeine at the excitation wavelength (290 nm). Therefore, a suitable correction of the obtained data was performed and the binding constant for caffeine binding to HSA was estimated, revealing low affinity of caffeine for HSA Ks = (12 ±1) *10³ mol–1 dm. Further, electron paramagnetic resonance (EPR) spectroscopy, using three different positional isomers of spin labeled stearic acid, doxyl stearates, was applied to study the caffeine-HSA interaction in further detail. It was found that upon caffeine binding, the hyperfine splitting decreases for HSA labeled with 5-doxylstearate. This phenomenon may indicate either an increase in mobility or a local change in polarity sensed by reporter groups upon caffeine binding. These observations may be important for the functional characteristics of HSA.Predmet ovoga istraživanja je vezanje kofeina na albumin iz ljudskoga seruma (HSA) s ciljem određivanja točne metodologije obrade dobivenih eksperimentalnih podataka. Naime, ustanovljeno je da na rezultate iz literature dobivene uporabom fluorescencijske spektroskopije utječe učinak unutarnjega filtera, kojega nije moguć e zanemariti. Učinak unutarnjega filtera prisutan je uslijed snažne apsorpcije kofeina na valnoj duljini pobude fluorescencije HSA (290 nm). Stoga je u ovome radu provedena korekcija dobivenih eksperimentalnih podataka te je procijenjena konstanta vezanja kofeina na HSA. Nadalje, za istraživanje interakcije kofeina i HSA primijenjena je spektroskopija elektronske paramagnetske rezonancije uz uporabu triju izomera spinski označene stearinske kiseline, doksil-stearata. Dobiveni rezultati ukazuju na smanjenje hiperfinoga cijepanja spektra HSA obilježenoga 5-doksil-stearatom u prisutnosti kofeina. Taj rezultat, zajedno s uočenim promjenama spektralnih amplituda, upućuje na povećanje mobilnosti spinske oznake u prisutnosti kofeina, uslijed poveć anja lokalne pokretljivosti proteina

Signatures of conformational stability and oxidation resistance in proteomes of pathogenic bacteria

Protein oxidation is known to compromise vital cellular functions. Therefore, invading pathogenic bacteria must resist damage inflicted by host defenses via reactive oxygen species. Using comparative genomics and experimental approaches, we provide multiple lines of evidence that proteins from pathogenic bacteria have acquired resistance to oxidative stress by an increased conformational stability. Representative pathogens exhibited higher survival upon HSP90 inhibition and a less-oxidation-prone proteome. A proteome signature of the 46 pathogenic bacteria encompasses 14 physicochemical features related to increasing protein conformational stability. By purifying ten representative proteins, we demonstrate in vitro that proteins with a pathogen-like signature are more resistant to oxidative stress as a consequence of their increased conformational stability. A compositional signature of the pathogens’ proteomes allowed the design of protein fragments more resilient to both unfolding and carbonylation, validating the relationship between conformational stability and oxidability with implications for synthetic biology and antimicrobial strategies

Antioxidants, radical-scavenging and protein carbonylation inhibition capacity of six monocultivar virgin olive oils in Istria (Croatia)

Six monocultivar virgin olive oils (VOOs) produced from five autochthonous (Buža, Buža Puntoža, Istarska Bjelica, Porečka Rosulja, and Rosinjola) and one referent cultivar (Leccino), were investigated. The mass fractions of orthodiphenols (ORT) and tocopherols (TOC) were analysed by VIS spectroscopy and HPLC. The radical-scavenging capacity was evaluated by electron spin resonance spectroscopy (ESR) using galvinoxyl free radical and the DPPH test. Results revealed a high level of total TOC in VOOs of Buža Puntoža (243 mg kg−1) and Porečka Rosulja (325 mg kg−1). VOOs contained in 100 g from 79% (Istarska Bjelica) to 261% (Porečka Rosulja) of recommended daily allowance of α-tocopherol. The mass fraction of ORT in Istarska Bjelica and Rosinjola was >250 mg kg−1 (on average 30–40% higher in comparison to other studied cultivars). Istarska Bjelica and Porečka Rosulja showed the highest antioxidant capacity in both methods of measurement. The highest capacity to inhibit protein carbonylation (PC) in response to oxidative stress (54–56%) was displayed by Buža Puntoža, Leccino, and Buža. High level of positive linear correlation between ORT mass fraction and radical-scavenging capacity measured by DPPH test (r=0.768), as well as strong negative correlation between PC inhibition and mass fraction of ORT (r= −0.697), were observed

Clustering of protein domains for functional and evolutionary studies

Background: The number of protein family members defined by DNA sequencing is usually much larger than those characterised experimentally. This paper describes a method to divide protein families into subtypes purely on sequence criteria. Comparison with experimental data allows an independent test of the quality of the clustering. Results: An evolutionary split statistic is calculated for each column in a protein multiple sequence alignment; the statistic has a larger value when a column is better described by an evolutionary model that assumes clustering around two or more amino acids rather than a single amino acid. The user selects columns (typically the top ranked columns) to construct a motif. The motif is used to divide the family into subtypes using a stochastic optimization procedure related to the deterministic annealing EM algorithm (DAEM), which yields a specificity score showing how well each family member is assigned to a subtype. The clustering obtained is not strongly dependent on the number of amino acids chosen for the motif. The robustness of this method was demonstrated using six well characterized protein families: nucleotidyl cyclase, protein kinase, dehydrogenase, two polyketide synthase domains and small heat shock proteins. Phylogenetic trees did not allow accurate clustering for three of the six families. Conclusion: The method clustered the families into functional subtypes with an accuracy of 90 to 100%. False assignments usually had a low specificity score

The evolutionary signal in metagenome phyletic profiles predicts many gene functions

Background. The function of many genes is still not known even in model organisms. An increasing availability of microbiome DNA sequencing data provides an opportunity to infer gene function in a systematic manner. Results. We evaluated if the evolutionary signal contained in metagenome phyletic profiles (MPP) is predictive of a broad array of gene functions. The MPPs are an encoding of environmental DNA sequencing data that consists of relative abundances of gene families across metagenomes. We find that such MPPs can accurately predict 826 Gene Ontology functional categories, while drawing on human gut microbiomes, ocean metagenomes, and DNA sequences from various other engineered and natural environments. Overall, in this task, the MPPs are highly accurate, and moreover they provide coverage for a set of Gene Ontology terms largely complementary to standard phylogenetic profiles, derived from fully sequenced genomes. We also find that metagenomes approximated from taxon relative abundance obtained via 16S rRNA gene sequencing may provide surprisingly useful predictive models. Crucially, the MPPs derived from different types of environments can infer distinct, non-overlapping sets of gene functions and therefore complement each other. Consistently, simulations on > 5000 metagenomes indicate that the amount of data is not in itself critical for maximizing predictive accuracy, while the diversity of sampled environments appears to be the critical factor for obtaining robust models. Conclusions. In past work, metagenomics has provided invaluable insight into ecology of various habitats, into diversity of microbial life and also into human health and disease mechanisms. We propose that environmental DNA sequencing additionally constitutes a useful tool to predict biological roles of genes, yielding inferences out of reach for existing comparative genomics approaches

Energy Audit of Family House in Bílovec

Import 11/11/2010Tématem bakalářské práce je energetický audit rodinného domu v Bílovci. V úvodu se zabývám popisem této práce, dále pak základnímu popisu a vysvětlení metodiky energetického auditu. Dalším krokem je popis auditovaného objektu, podrobné zhodnocení stávajícího stavu včetně zhodnocení energetického hospodaření s energiemi za uplynulé tři roky. Dále počítám tepelné ztráty budovy obálkovou metodou dle normy ČSN 06 0210. Po stanovení tepelné ztráty budovy počítám měrnou potřebu tepla pro vytápění a ohřev teplé vody pro stávající stav budovy. Poté pro navržená úsporná opatření. V dalším kroku navrhuji vhodná úsporná opatření a alternativní zdroje tepla pro vytápění. Následuje ekonomické vyhodnocení jednotlivých úsporných opatření a v závěru se věnuji celkovému zhodnocení energetického auditu a jeho výsledkům.The theme of this dissertation is the energy audit of a family house in Bílovec. The description of this paper and basic.Explanation of the metodology of the energy audit are to be found at the beginning of this paper. Next, there are introduced. The description of the audit object, the detailed assessment of the current state including the assessment of energetic. Management during three years. Further, there are calculated heat losses of the building using the envelope method according. To the norm ČSN 06 0210, specific heat requirements for the heating of the building and the heating of hot supply water, based on the current state of the building and also on the suggested economy measures. Next, there are suggested appropriate. Economy measures and alternative heat sources for heating followed by the economic evaluation of particular economy measures. The conclusion deals with the total assessment of energy audit and its results.361 - Katedra energetikyvelmi dobř