193 research outputs found
Essential oil-water emulsions containing a biosurfactant from Lactobacillus paracasei
[Excerpt] Surfactants play important roles in cosmetic products due to diverse properties including as emulsifier, foaming, wetting, detergency and solubilizer agents, among others. However, the market for beauty and personal care products based on natural ingredients has shown a relevant growth. In this sense, biosurfactants being non-toxic, biodegradable and ecofriendly natural compounds are suitable replacers of the chemical-based surfactants showing equal or better performances [1]. In addition, essential oils are natural ingredients extracted from plants that also are interesting ingredients for novel cosmetic formulations.The aim of this study was to formulate oil-water emulsions using a biosurfactant from Lactobacil/us paracasei in combination with several essential oils (wheat germ, almond, rosemary and jojoba oil). [...]Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding
of UID/BI0/04469/2013 unit, COMPETE 2020 (POCl-01-0145-FEDER-006684) and the project RECl/BBB-EBl/0179/2012 (FCOMP-01-0124-FEDER-027462
Antimicrobial study of biosurfactants from Lactobacillus strains against skin pathogens
[Excerpt] Human skin microflora is composed by resident1 temporarily resident and transient microbial species. Therefore, gram-positive bacteria from the genera Propionibacterium, Staphylococcus, Micrococcus, Corynebaderium and Acinetobacter are the majority microorganisms present in the resident microflora [1 ]. For instance, Staphylococcus epidermidis is the main constituent of skin microflora, which protects the human skin from infections; whereas Staphylococcus aureus is a common transient species, which causes skin infections [2]. Anti-bacterial preservatives such as triclosan, methylparaben or bronopol, among others, are currently used as ingredients in the skin and oral care cosmetic products. However, there is a growing demand for cosmetics free of synthetic preservatives [3]. In this sense, biosurfactants from lactic acid bacteria, which are generally recognized as safe by the American Food and Drug Administration, are natural compounds that exhibit antimicrobial activity and therefore, could be used as an alternative to the chemically synthetized preservatives. The aim of this study was to evaluate the antimicrobial activity of biosurfactants obtained from two different Lactobacillus strains (L. pentosus and L. paracasef) against skin pathogenic microorganisms. [...]Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of
UID/BI0/04469/2013 unit, COMPETE 2020 (POCl-01-0145-FEDER-006684) and the project
RECl/BBB-EBl/0179/2012 (FCOMP-01-0124-FEDER-027462
New approach on the bioconversion of vineyard pruning waste into surface-active compounds by Lactobacillus paracasei
Strategic funding of UID/BIO/04469/2013 unit and project ref RECI/BBB-EBI/0179/2012 (project number FCOMP-01-0124-FEDER-027462)
and Xanel Vecino post-doctoral grant (ref SFRH/BPD/101476/2014) funded by Fundação para a Ciência e a Tecnologia, Portuga
The influence of the medium composition on the biosurfactants produced by Lactobacillus paracasei
[Excerpt] Lactic acid bacteria is an interesting group of microorganisms for the production of biosurfactants. In addition, these bacteria are generally recognized as safe by the American Food and Drug Administration. An example is the Lactobacil/us paracasei that was isolated from a Portuguese dairy industry and has been previously reported by Gudina and collaborators [1] forthe production of biosurfactants.The biosurfactants produced by LAB are cell-bound biosurfactants contrarily to the most well-known extracellular biosurfactants produced by Pseudomonas or Bacillus species. The main bottleneck of their industrial production and application is related with the production and recovery costs. Therefore, many studies are focusing on the use of renewable agroindustrial wastes as carbon sources in the fermentative processes [2]. The aim of this work was the production and characterization of biosurfactants by L. paracasei using a lignocellulosic residue (vineyard pruning waste) as carbon source. The vineyard pruning waste was subjected to a fractionation process to obtain cellulose, which was next submitted to a saccharification step with enzymes in order to convert cellulose in a glucose-based fermentation media. Once this glucose solution was obtained, it was further supplemented with 1 O g/L of yeast extract and 1 O g/L of corn steep liquor. [...]Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding
of UID/BI0/04469/2013 unit, COMPETE 2020 (POCl-01-0145-FEDER-006684)
and the project RECl/BBB-EBl/0179/2012 (FCOMP-01-0124-FEDER-02746
Vineyard pruning waste as an alternative carbon source to produce novel biosurfactants by Lactobacillus paracasei
Abstract Cellulosic sugars extracted from vineyard pruning waste (VPW) were used as a low-cost carbon source for biosurfactant production by Lactobacillus paracasei. The results obtained showed that when glucose from VPW was used, the biosurfactant was a glycolipopeptide, whereas when it was replaced by lactose the biosurfactant produced was a glycoprotein. Additionally, it was found that the extraction process, either with phosphate-buffer or phosphate-buffer saline, influenced the biosurfactant chemical structure and emulsion capacity. Overall, these results highlight the possibility of producing biosurfactants à la carte with the same strain but changing the carbon source, increasing its potential in different industrial applications.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462), as well as X. Vecino post-doctoral grant (SFRH/BPD/101476/2014). The authors also acknowledge financial support from BioTecNorte operation (NORTE-01-0145-FEDER-000004) and the project MultiBiorefinery (POCI-01-0145-FEDER-016403) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte and the Post-doctoral grant CEB-BPD/01/2015/07 from the project UID/BIO/04469/2013, funded by FCT, to E. Gudiña. Additionally, the authors acknowledge the financial support from Spanish Ministry of Economy and Competitiveness (FEDER funds under the project CTM2015-68904) and L. RodrÃguez-López acknowledges to the Spanish Ministry of Education, Culture and Sport for her pre-doctoral fellowship (FPU15/00205).info:eu-repo/semantics/publishedVersio
Phylogenetic relationships of the Amblyomma cajennense complex (Acari: Ixodidae) at mitogenomic resolution
The genus Amblyomma is the third most diverse in the number of species within the Ixodidae, with practically half of its species distributed in the Americas, though there are also species occurring in Africa, Asia, and Australia. Within the genus, there are several species complexes with veterinary and public health importance. The Amblyomma cajennense complex, in the Americas, is represented by six species with a wide distribution, from Texas to northern Argentina. We combined two sequencing techniques to generate complete mitogenomes of species belonging to the Amblyomma cajennense complex: genome skimming and long-range PCRs sequencing methods. Thus, we generated seven new mitochondrial genomes for all species of the Amblyomma cajennense complex, except for Amblyomma interandinum. Genetic distances between the mitogenomes corroborate the clear differentiation between the five species of the Amblyomma cajennense complex. The phylogenetic relationships of these species had previously been evaluated by combining partial nuclear and mitochondrial genes and here these relationships are corroborated with a more robust framework of data, which demonstrates that the conjunction of mitochondrial and nuclear partial genes can resolve close relationships when entire genes or genomes are unavailable. The gene order, structure, composition, and length are stable across these mitogenomes, and they share the general characteristics of Metastriata. Future studies should increase the number of available mitogenomes for this genus, especially for those species from the Indo-Pacific region and Africa, by means of a better understanding of their relationships and evolutionary process.EEA RafaelaFil: Cotes-Perdomo, Andrea P. Museo Nacional de Ciencias Naturales (MNCN-CSIC), Departamento de Biodiversidad y BiologÃa Evolutiva; EspañaFil: Cotes-Perdomo, Andrea P. University of South-Eastern. Faculty of Technology. Natural Sciences and Environmental Health Department. Natural Sciences and Maritime Sciences; NoruegaFil: Nava, Santiago. Instituto Nacional de TecnologÃa Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Nava, Santiago. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Nava, Santiago. Instituto Nacional de TecnologÃa Agropecuaria. Instituto de Investigación de la Cadena Láctea (IDICAL); ArgentinaFil: Castro, Lyda R. Universidad del Magdalena. Facultad de Ciencias Básicas. Grupo de investigación Evolución, Sistemática y EcologÃa Molecular (GIESEMOL); ColombiaFil: Rivera-Paéz, Fredy A. Universidad de Caldas. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Biológicas. Grupo de Investigación en Genética, Biodiversidad y Manejo de Ecosistemas (GEBIOME); ColombiaFil: Cortés-Vecino, Jesús A. Universidad Nacional de Colombia. Facultad de Medicina Veterinaria y de Zootecnia. Grupo de Investigación ParasitologÃa Veterinaria; ColombiaFil: Uribe, Juan E. Museo Nacional de Ciencias Naturales (MNCN-CSIC). Departamento de Biodiversidad y BiologÃa Evolutiv; EspañaFil: Uribe, Juan E. Smithsonian Institution. National Museum of Natural History. Invertebrate Zoology Department; Estados Unido
Intraoperative goal directed hemodynamic therapy in noncardiac surgery: a systematic review and meta-analysis
Background: The goal directed hemodynamic therapy is an approach focused on the use of cardiac output and related parameters as end-points for fluids and drugs to optimize tissue perfusion and oxygen delivery. Primary aim: To determine the effects of intraoperative goal directed hemodynamic therapy on postoperative complications rates.
Methods: A meta-analysis was carried out of the effects of goal directed hemodynamic therapy in adult noncardiac surgery on postoperative complications and mortality using Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology. A systematic search was performed in Medline PubMed, Embase, and the Cochrane Library (last update, October 2014). Inclusion criteria were randomized clinical trials in which intraoperative goal directed hemodynamic therapy was compared to conventional fluid management in noncardiac surgery. Exclusion criteria were trauma and pediatric surgery studies and that using pulmonary artery catheter. End-points were postoperative complications (primary) and mortality (secondary). Those studies that fulfilled the entry criteria were examined in full and subjected to quantifiable analysis, predefined subgroup analysis (stratified by type of monitor, therapy, and hemodynamic goal), and predefined sensitivity analysis.
Results: 51 RCTs were initially identified, 24 fulfilling the inclusion criteria. 5 randomized clinical trials were added by manual search, resulting in 29 randomized clinical trials in the final analysis, including 2654 patients. A significant reduction in complications for goal directed hemodynamic therapy was observed (RR: 0.70, 95% CI: 0.62-0.79, p < 0.001). No significant decrease in mortality was achieved (RR: 0.76, 95% CI: 0.45-1.28, p = 0.30). Quality sensitive analyses confirmed the main overall results.
Conclusions: Intraoperative goal directed hemodynamic therapy with minimally invasive monitoring decreases postoperative complications in noncardiac surgery, although it was not able to show a significant decrease in mortality rate
Dephasing of Andreev pairs entering a charge density wave
An Andreev pair from a s-wave superconductor (S) entering a conventional
gapless charge density wave (CDW) below the Peierls gap dephases on the Fermi
wavelength while one particle states are localized on the CDW coherence length.
The paths following different sequences of impurities interfere destructively,
due to the different electron and hole densities in the CDW. The same
conclusion holds for averaging over the conduction channels in the ballistic
system. We apply two microscopic approaches to this phenomenon: i) a Blonder,
Tinkham, Klapwijk (BTK) approach for a single highly transparent S-CDW
interface; and ii) the Hamiltonian approach for the Josephson effect in a clean
CDW and a CDW with non magnetic disorder. The Josephson effect through a spin
density wave (SDW) is limited by the coherence length, not by the Fermi
wave-length.Comment: 8 pages, 2 figures, revised manuscrip
Quantum phase transition in a minimal model for the Kondo effect in a Josephson junction
We propose a minimal model for the Josephson current through a quantum dot in
a Kondo regime. We start with the model that consists of an Anderson impurity
connected to two superconducting (SC) leads with the gaps
, where for the lead at left and right. We show that, when one of the SC gaps is
much larger than the others , the starting model can
be mapped exactly onto the single-channel model, which consists of the right
lead of and the Anderson impurity with an extra onsite SC gap of
. Here and are
defined with respect to the starting model, and is the level width
due to the coupling with the left lead. Based on this simplified model, we
study the ground-state properties for the asymmetric gap, , using the numerical renormalization group (NRG) method. The
results show that the phase difference of the SC gaps , which induces the Josephson current, disturbs the screening of the
local moment to destabilize the singlet ground state typical of the Kondo
system. It can also drive the quantum phase transition to a magnetic doublet
ground state, and at the critical point the Josephson current shows a
discontinuous change. The asymmetry of the two SC gaps causes a re-entrant
magnetic phase, in which the in-gap bound state lies close to the Fermi level.Comment: 23 pages, 13 figures, typos are correcte
The impact of clothing style on bone mineral density among post menopausal women in Morocco: a case-control study
BACKGROUND: The clothing style is an important factor that influences vitamin D production and thus bone mineral density. We performed a case-control study in order to evaluate the effect of veil wearing (concealing clothing) on bone mineral density in Moroccan post menopausal women. METHODS: The cases were osteoporotic women whose disease was assessed by bone mineral density measurement. Each patient was matched with a non osteoporotic woman for age, and body mass index. All our patients were without secondary causes or medications that might affect bone density. The veil was defined as a concealing clothing which covered most of the body including the arms, the legs and the head. This definition is this of the usual Moroccan traditional clothing style. RESULTS: 178 post menopausal osteoporotic patients and 178 controls were studied. The mean age of the cases and the controls was 63.2 years (SD 7) and the mean body mass index was 32.1 (SD 8). The results of crude Odds Ratios analyses indicated that wearing a veil was associated with a high risk of osteoporosis: OR 2.29 (95% CI, 1.38–3.82). Multiparity or a history of familial peripheral osteoporotic fractures had also a significant effect on increasing the osteoporosis risk (ORs: 1.87 (95% CI, 1.05–3.49) and 2.01 (95% CI, 1.20–3.38)). After a multiple regression analysis, wearing the veil and a history of familial osteoporotic fractures remained the both independent factors that increased the osteoporosis risk (ORs: 2.20 (95% CI, 1.22–3.9) and 2.19 (95% CI, 1.12–4.29) respectively). CONCLUSION: our study suggested that in Moroccan post menopausal women, wearing a traditional concealing clothing covering arms, legs and head increased the risk of osteoporosis. Further studies are required to evaluate the clinical impact of the above findings and to clarify the status of vitamin D among veiled women in Morocco
- …