Broadband Spectral Analysis of Non-Debye Dielectric Relaxation in Percolating Heterostructures

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Biochemical characterization of a cefotaximehydrolysing &#946-lactamase encoded by a conjugative plasmid

During the nosocomials infections occurring in the intensive care unit of the military hospital of Tunis in 2005, the Enterobacter cloacae BW 1150 strain was isolated from a stool culture. This strain was found to have a high level resistance to broad-spectrum -lactams. Resistance profile against thevarious families of antibiotics was determined using the disc diffusion test. The minimal inhibitory concentrations values showed that this strain was resistant to the -lactams such as ampicillin and the extended spectrum cephalosporins (cefotaxime, ceftriaxon and cefpirome). Analysis of this strain by the disk diffusion test revealed synergies between amoxicillin-clavulanate (AMX-CA) and ceftriaxon, ceftazidime and cefotaxime. Cell sonicate of this isolate is very active against cefotaxime and showed aspecific activity (AS) of 7.54 U/mg for the same antibiotic. This activity was inhibited by the sulbactam and the clavulanic acid. Isoelectrofocusing methods revealed that the crude extract of the E. cloacae BW 1150 strain showed 1 - lactamase activity with an isoelectric piont (pI) of about 8. This activity was transferred by conjugation and was highly expressed in the transconjugant

Influence of Gravity on noncommutative Dirac equation

In this paper, we investigate the influence of gravity and noncommutativity on Dirac equation. By adopting the tetrad formalism, we show that the modified Dirac equation keeps the same form. The only modification is in the expression of the covariant derivative. The new form of this derivative is the product of its counterpart given in curved space-time with an operator which depends on the noncommutative $\theta$-parameter. As an application, we have computed the density number of the created particles in presence of constant strong electric field in an anisotropic Bianchi universe.Comment: 9 pages, correct some miprints, Accepted for publication in journal of Mod. Phys. Letters

Assisted dipeptide bond formation : glycine as a case study

Peptide bond formation is a crucial chemical process that dominates most biological mechanisms and is claimed to be a governing factor in the origin of life. Dipeptides made from glycine are studied computationally via Density Functional Theory (DFT) using two different basis sets. This reaction was investigated from both a thermodynamic and kinetic point of view. The effect of explicit assistance via the introduction of discrete solvent molecules was investigated. Water, methanol, and cyclohexane were all employed as solvent media in addition to gas to investigate their effects on the mechanism of peptide bond formation. This computational investigation revealed that methanol is slightly better than water to leverage peptide bond formation both kinetically and thermodynamically, while cyclohexane, a non-polar and non-protic solvent, is the least effective after gas as a medium of solvation. Energetic results in the gas environment are very close to those obtained in polar and protic solvents, suggesting that peptide bonds can be formed under interstellar conditions

Contribution of the phenolic composition to the antioxidant, anti-inflammatory and antitumor potential of Equisetum giganteum L. and Tilia platyphyllos Scop.

Naturally-occurring phytochemicals have received pivotal attention in the last few years, due to the increasing evidence of biological activities. Thus, in the present study, the antioxidant, anti-inflammatory and antitumor potentials of hydroethanolic extracts rich in phenolic compounds obtained from Equisetum giganteum L. and Tilia platyphyllos Scop. were assessed and directly correlated with their content of phenolic compounds, by using HPLC-DAD-ESI/MS analysis. T. platyphyllos showed the higher bioactive potential, evaluated in terms of antioxidant (radical scavenging effects-105 µg mL -1 , reducing power-123 µg mL -1 , ß-carotene bleaching inhibition-167 µg mL -1 , and lipid peroxidation inhibition-56 µg mL -1 ), anti-inflammatory (225 µg mL -1 inhibited 50% of nitric oxide production) and antitumor (breast-224 µg mL -1 ; lung-247 µg mL -1 ; cervical-195 µg mL -1 and hepatocellular-173 µg mL -1 carcinoma cells) activity, without having cytotoxic effects ( > 400 µg mL -1 ). These biological properties were positively correlated with its content and composition of phenolic compounds. Flavonoid contents were markedly higher than the content of phenolic acids, in both samples, being respectively 50.4 mg g -1 and 11.65 mg g -1 for T. platyphyllos, and 21.7 mg g -1 and 4.98 mg g -1 for E. giganteum. Moreover, while in E. giganteum extract, kaempferol-O-glucoside-O-rutinoside was the most abundant flavonoid, in T. platyphyllos extract protocatechuic acid and (-)-epicatechin were the most abundant phenolic acid and flavonoid, respectively. In relation to their content of phenolic acids, protocatechuic and caffeic acids existed in higher abundance in T. platyphyllos and E. giganteum hydroethanolic extracts, respectively. However, it would be interesting to evaluate the in vivo efficacy of both plant extracts to unveil the involved modes of action and to establish effective therapeutic doses.The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (Pest-OE/AGR/UI0690/2015) and to POCI-01-0145-FEDER- 006984 (LA LSRE-LCM) funded by ERDF through POCICOMPETE2020 and FCT. L. Barros and N. Martins thank FCT for their grants (SFRH/BPD/107855/2015 and SFRH/BD/87658/ 2012, respectively). The GIP-USAL is financially supported by the Spanish Government through the project AGL2015-64522- C2-2-R.info:eu-repo/semantics/publishedVersio

Glycosylation Tunes Neuroserpin Physiological and Pathological Properties

Neuroserpin (NS) is a member of the serine protease inhibitors superfamily. Specific point mutations are responsible for its accumulation in the endoplasmic reticulum of neurons that leads to a pathological condition named familial encephalopathy with neuroserpin inclusion bodies (FENIB). Wild-type NS presents two N-glycosylation chains and does not form polymers in vivo, while non-glycosylated NS causes aberrant polymer accumulation in cell models. To date, all in vitro studies have been conducted on bacterially expressed NS, de facto neglecting the role of glycosylation in the biochemical properties of NS. Here, we report the expression and purification of human glycosylated NS (gNS) using a novel eukaryotic expression system, LEXSY. Our results confirm the correct N-glycosylation of wild-type gNS. The fold and stability of gNS are not altered compared to bacterially expressed NS, as demonstrated by the circular dichroism and intrinsic tryptophan fluorescence assays. Intriguingly, gNS displays a remarkably reduced polymerisation propensity compared to non-glycosylated NS, in keeping with what was previously observed for wild-type NS in vivo and in cell models. Thus, our results support the relevance of gNS as a new in vitro tool to study the molecular bases of FENIB

Bioactivity, proximate, mineral and volatile profiles along the flowering stages of Opuntia microdasys (Lehm.): defining potential applications

Opuntia spp. flowers have been traditionally used for medical purposes, mostly because of their diversity in bioactive molecules with health promoting properties. The proximate, mineral and volatile compound profiles, together with the cytotoxic and antimicrobial properties were characterized in O. microdasys flowers at different maturity stages, revealing several statistically significant differences. O. microdasys stood out mainly for its high contents of dietary fiber, potassium and camphor, and its high activities against HCT15 cells, Staphylococcus aureus, Aspergillus versicolor and Penicillium funiculosum. The vegetative stage showed the highest cytotoxic and antifungal activities, whilst the full flowering stage was particularly active against bacterial species. The complete dataset has been classified by principal component analysis, achieving clearly identifiable groups for each flowering stage, elucidating also the most distinctive features, and comprehensively profiling each of the assayed stages. The results might be useful to define the best flowering stage considering practical application purposes.The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011) and ALIMNOVA research group (UCM-GR35/10A). J.C.M. Barreira and R.C. Calhelha thank FCT, POPH-QREN and FSE for their grants (SFRH/BPD/72802/2010 and SFRH/BPD/68344/2010, respectively). The Serbian Ministry of Education is also acknowledged for the Science and Technological Development Grant No. 173032

Bioactivity and chemical characterization of Opuntia macrorhiza Engelm. seed oil: potential food and pharmaceutical applications

In the food industry, there is a continuous search for ingredients that might provide advantageous properties to food products, either considering their nutritional value or bioactivity, as well as flavouring and technological aspects. Crude oils are good examples of this type of ingredient, especially if obtained from nonconventional sources. Accordingly, the Opuntia macrorhiza Engelm. seed oil (OMSO) was chemically characterized and evaluated for different in vitro and in vivo bioactivities. OMSO presented physicochemical characteristics appropriate to be considered as an edible oil, namely low acidity value, stability to oxidation (high peroxide value and low K 232 and K 270 values), and high contents of unsaturated fatty acids (as shown by the iodine value) and saponifiable matter. Furthermore, this natural oil, owing to its rich phytochemical profile, showed relevant antioxidant activity (especially in lipid peroxidation inhibition assays), a-glucosidase inhibitory activity, cytotoxicity against human tumour cell lines, antibacterial (mainly against Gram positive species) and antifungal properties, as well as anti-inflammatory and analgesic activities. Furthermore, OMSO did not show any sign of acute toxicity on animals, highlighting its possible use in different applications, considering that this natural product is not expected to induce the adverse effects typically associated with synthetic bioactive agents (e.g., ampicillin, amphotericin B, or lysine acetylsalicilate).The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011) and J.C.M. Barreira and Ricardo C. Calhelha contracts.info:eu-repo/semantics/publishedVersio

Bioactivity, hydrophilic, lipophilic and volatile compounds in pulps and skins of Opuntia macrorhiza and Opuntia microdasys fruits

Opuntia genus includes several species able to grow in arid regions and known for producing delicate fruits, which are far from being thoroughly characterized. Herein, fruits from O. macrorhiza and O. microdasys were divided in skins and pulps (without including seeds) and studied for chemical composition, individual phytochemicals and bioactivity. The major volatiles were camphor and ethyl acetate, while citric acid was the main organic acid. The fatty acids detected in highest percentages were linoleic acid (skins) and lauric acid (pulps); α- tocopherol was the major isoform of vitamin E. Quercetin-3-O-rutinoside and quercetin-O-(deoxyhexoside-rutinoside) were the main phenolics in fruit skins of O. macrorhiza and O. microdasys (respectively), similarly to piscidic acid in O. macrorhiza pulp (O. microdasys pulp showed no quantifiable compounds). Betanin and isobetanin were the major betalains. All samples were antioxidant (particularly O. macrorhiza), but antimicrobial activity was only detected in skins. Cytotoxicity was low in all cases. Overall, these fruits proved to be potential new ingredients for food or pharmaceutical related applications, adding value to these natural species able to grow in arid environments.Authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013), C2TN (UID/Multi/04349/ 2013), L. Barros, J. Barreira and R. Calhelha contracts. This work is funded by the European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project Mobilizador ValorNatural®. Authors also thank FEDER Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

Learning lessons from the 2011 Van Earthquake to enhance healthcare surge capacity in Turkey

Historically, Turkey has adopted a reactive approach to natural hazards which resulted in significant losses. However, following the 1999 Kocaeli Earthquake, a more proactive approach has been adopted. This study aims to explore the way this new approach operates on the ground. A multi-national and multi-disciplinary team conducted a field investigation following the 2011 Van Earthquake to identify lessons to inform healthcare emergency planning in Turkey and elsewhere. The team interviewed selected stakeholders including, healthcare emergency responders, search and rescue services, ambulance services, and health authority representatives, in addition to conducting a focus group. Data were analysed according to an open coding process and SWOT analysis. The findings suggest that the approach succeeded in developing a single vision by consolidating official efforts in a more structured way, mobilising many governmental and non-governmental organisations, securing significant amounts of resources including physical and human, and increasing the resilience and flexibility of infrastructure to expand its capacity. However, more attention is required to the development of stronger management procedures and acquisition of further resources