970 research outputs found
The KLa influence on ethanol production by Pichia stipitis
Nowadays, there is a great interest in the development of technologies for
ethanol production as an alternative combustible, since it can be used instead
of petrol or to blend with petrol, reducing the country’s dependence on oil
and imported fuel. It is known that the ethanol production by fermentation
is influenced by several process conditions such as pH, temperature, medium
composition, oxygen availability, among others. Determining the most suitable
fermentation conditions is of large importance for the establishment of a
successful technology. In the present work, the influence of oxygen transfer
volumetric rate (KL
a) on xylose to ethanol bioconversion by the yeast Pichia
stipitis NRRL Y-7124 was evaluated using a semi-defined fermentation medium
containing 90 g/l xylose. The assays were carried out in a bioreactor at 30°C,
under different aeration conditions (0.5, 1.0, and 1.5 vvm) and stirring rates
(200, 300 and 400 rpm) which resulted in KL
a values of 2.3, 18.7 and 65.8 h-1
respectively. According to the results, the bioconversion was dependent
on the aeration rate employed, the highest ethanol production (27.1 g/l)
being achieved when using a KL
a of 2.3 h-1. The increase of this parameter
to 18.7 and 65.8 h-1 promoted decreases of 52% and 100% on ethanol
production, respectively. By using a KL
a of 65.8 h-1 the ethanol production was
totally deviated to biomass production. Such results are of interest for the
development of a suitable technology for ethanol production by Pichia stipitis
Early Proterozoic calc-alkaline and Middle Proterozoic tholeiitic dyke swarms from Central-Eastern Argentina: Petrology, geochemistry, Sr-Nd isotopes and tectonic implications
The Rio de La Plata craton in Argentina (Azul and Tandil regions) is characterized by Early Proterozoic (2·0 Ga) calc-alkaline and Middle Proterozoic (1·6 Ga) tholeiitic dyke swarms intruding the crystalline basement involved in the Transamazonian Orogeny (2·2-1·9 Ga). The calc-alkaline dykes have andesitic and rhyolitic compositions and trend east-west, whereas the tholeiitic dykes mainly trend N30°W and are represented by basalts with low (0·9-1·7 wt %) and high TiO2 (up to 3·7 wt %). The calc-alkaline dykes have primitive mantle (PM)-normalized trace element patterns enriched in Rb, Ba, K, La, Ce and Nd, and significant negative Nb and Ti anomalies. These dykes are characterized by εt(Nd) values of - 3 to - 4, similar to those of the EMI mantle component. Low-TiO2 tholeiitic dykes have low incompatible-element (IE) contents and PM-IE patterns with slightly positive or negative Nb spikes. They have variable εt(Nd) values (-0·5 to 12·1), which mainly reflect derivation from a depleted source mantle. High-TiO2 tholeiitic dykes have more enriched IE-PM patterns and are characterized by εt(Nd) values (-1·4 to -7·5) typical of an enriched source mantle. Chemical and isotopic data and melting modelling indicate that both calc-alkaline and tholeiitic dykes originated by different melting degrees of a heterogeneous source mantle, the variable IE enrichment of which may have occured in Late Archaean to Early Proterozoic times. The emplacement of the calc-alkaline dykes is associated with the transtensional stage of the Transamazonian Orogeny, whereas the tholeiitic dykes reflect extensional tectonics succeeding the Transamazonian event. The calc-alkaline and tholeiitic dykes are similar in emplacement age and characteristics to metamorphosed granites and volcanic rocks outcropping within the Namaqua fold belts of southwestern Africa (Richtersveld and Witberg-Aggeneys-Gamsberg provinces); this may indicate that the Rio de La Plata craton and southwestern Africa were contiguous in Early-Middle Proterozoic times.Facultad de Ciencias Naturales y MuseoLaboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológic
Potential risks in drug prescriptions to elderly: a cross-sectional study in the public primary health care system of Ourinhos Micro-region, Brazil
This research aimed to assess the occurrence of potential risks in drug prescriptions to elderly at the Brazilian public primary health care. A cross-sectional, multicenter research was carried out at the pharmacies of public primary health care in five cities of the Ourinhos Micro-region, Sao Paulo, Brazil. Potential drug-drug interactions (DDIs) (according to three DDIs investigation software programs), drugs that act on cytochrome P450 system (CYP450) and potentially inappropriate medications (PIM) for elderly people (according to the Beers criteria (2003)) were selected as indicators of potential risks. A total of 2,627 prescriptions were collected and evaluated. Major DDIs were found in 2.6 % to 3.4 % of the prescriptions, depending on the software used. The prevalence of prescriptions containing drugs that acted on CYP450 was 50.9 %. PIM were found in 26.9 % prescriptions. These data indicate high prevalence of potential risks in drugs prescriptions to elderly at Ourinhos Micro-region public primary health care.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Molecular characterization of the Corynebacterium pseudotuberculosis hsp60-hsp10 operon, and evaluation of the immune response and protective efficacy induced by hsp60 DNA vaccination in mice
<p>Abstract</p> <p>Background</p> <p>Heat shock proteins (HSPs) are important candidates for the development of vaccines because they are usually able to promote both humoral and cellular immune responses in mammals. We identified and characterized the <it>hsp60-hsp10 </it>bicistronic operon of the animal pathogen <it>Corynebacterium pseudotuberculosis</it>, a Gram-positive bacterium of the class <it>Actinobacteria</it>, which causes caseous lymphadenitis (CLA) in small ruminants.</p> <p>Findings</p> <p>To construct the DNA vaccine, the <it>hsp60 </it>gene of <it>C. pseudotuberculosis </it>was cloned in a mammalian expression vector. BALB/c mice were immunized by intramuscular injection with the recombinant plasmid (pVAX1/<it>hsp60</it>).</p> <p>Conclusion</p> <p>This vaccination induced significant anti-hsp60 IgG, IgG1 and IgG2a isotype production. However, immunization with this DNA vaccine did not confer protective immunity.</p
Search for CP Violation in the Decay Z -> b (b bar) g
About three million hadronic decays of the Z collected by ALEPH in the years
1991-1994 are used to search for anomalous CP violation beyond the Standard
Model in the decay Z -> b \bar{b} g. The study is performed by analyzing
angular correlations between the two quarks and the gluon in three-jet events
and by measuring the differential two-jet rate. No signal of CP violation is
found. For the combinations of anomalous CP violating couplings, and , limits of \hat{h}_b < 0.59h^{\ast}_{b} < 3.02$ are given at 95\% CL.Comment: 8 pages, 1 postscript figure, uses here.sty, epsfig.st
Early Proterozoic calc-alkaline and Middle Proterozoic tholeiitic dyke swarms from Central-Eastern Argentina: Petrology, geochemistry, Sr-Nd isotopes and tectonic implications
The Rio de La Plata craton in Argentina (Azul and Tandil regions) is characterized by Early Proterozoic (2·0 Ga) calc-alkaline and Middle Proterozoic (1·6 Ga) tholeiitic dyke swarms intruding the crystalline basement involved in the Transamazonian Orogeny (2·2-1·9 Ga). The calc-alkaline dykes have andesitic and rhyolitic compositions and trend east-west, whereas the tholeiitic dykes mainly trend N30°W and are represented by basalts with low (0·9-1·7 wt %) and high TiO2 (up to 3·7 wt %). The calc-alkaline dykes have primitive mantle (PM)-normalized trace element patterns enriched in Rb, Ba, K, La, Ce and Nd, and significant negative Nb and Ti anomalies. These dykes are characterized by εt(Nd) values of - 3 to - 4, similar to those of the EMI mantle component. Low-TiO2 tholeiitic dykes have low incompatible-element (IE) contents and PM-IE patterns with slightly positive or negative Nb spikes. They have variable εt(Nd) values (-0·5 to 12·1), which mainly reflect derivation from a depleted source mantle. High-TiO2 tholeiitic dykes have more enriched IE-PM patterns and are characterized by εt(Nd) values (-1·4 to -7·5) typical of an enriched source mantle. Chemical and isotopic data and melting modelling indicate that both calc-alkaline and tholeiitic dykes originated by different melting degrees of a heterogeneous source mantle, the variable IE enrichment of which may have occured in Late Archaean to Early Proterozoic times. The emplacement of the calc-alkaline dykes is associated with the transtensional stage of the Transamazonian Orogeny, whereas the tholeiitic dykes reflect extensional tectonics succeeding the Transamazonian event. The calc-alkaline and tholeiitic dykes are similar in emplacement age and characteristics to metamorphosed granites and volcanic rocks outcropping within the Namaqua fold belts of southwestern Africa (Richtersveld and Witberg-Aggeneys-Gamsberg provinces); this may indicate that the Rio de La Plata craton and southwestern Africa were contiguous in Early-Middle Proterozoic times.Facultad de Ciencias Naturales y MuseoLaboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológic
Uso de motores monofásicos acoplados mecanicamente em série, em irrigação por pivô central
Immobilization and application of the recombinant xylanase GH10 of Malbranchea pulchella in the production of xylooligosaccharides from hydrothermal liquor of the eucalyptus (Eucalyptus grandis) wood chips
Xylooligosaccharides (XOS) are widely used in the food industry as prebiotic components. XOS with high purity are required for practical prebiotic function and other biological benefits, such as antioxidant and inflammatory properties. In this work, we immobilized the recombinant endo-1,4-β-xylanase of Malbranchea pulchella (MpXyn10) in various chemical supports and evaluated its potential to produce xylooligosaccharides (XOS) from hydrothermal liquor of eucalyptus wood chips. Values >90% of immobilization yields were achieved from amino-activated supports for 120 min. The highest recovery values were found on Purolite (142%) and MANAE-MpXyn10 (137%) derivatives, which maintained more than 90% residual activity for 24 h at 70 °C, while the free-MpXyn10 maintained only 11%. In addition, active MpXyn10 derivatives were stable in the range of pH 4.0–6.0 and the presence of the furfural and HMF compounds. MpXyn10 derivatives were tested to produce XOS from xylan of various sources. Maximum values were observed for birchwood xylan at 8.6 mg mL−1 and wheat arabinoxylan at 8.9 mg mL−1, using Purolite-MpXyn10. Its derivative was also successfully applied in the hydrolysis of soluble xylan present in hydrothermal liquor, with 0.9 mg mL−1 of XOS after 3 h at 50 °C. This derivative maintained more than 80% XOS yield after six cycles of the assay. The results obtained provide a basis for the application of immobilized MpXyn10 to produce XOS with high purity and other high-value-added products in the lignocellulosic biorefinery field.The authors gratefully acknowledge FAPESP (São Paulo Research Foundation, grants No: 2018/07522-6) and FCT (POCI-01-0145-FEDER-032206)—transnational cooperation project EcoTech, and National Institute of Science and Technology of Bioethanol, INCT, CNPq 465319/2014-9/FAPESP n ◦ 2014/50884- 5) for financial support. Research scholarships were granted to RCA, DA, and JCSS by FAPESP (Grant No: 2020/00081-4, 2020/15510-8, and 2019/21989-7, respectively), to CCVD and VEP by CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Finance Code 001).info:eu-repo/semantics/publishedVersio
Standalone vertex finding in the ATLAS muon spectrometer
A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011
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