An Optical Overview of Poly[μ2-L-alanine-μ3-nitrato-sodium(I)] Crystals

Single crystals of the semiorganic materials, L-alanine sodium nitrate (LASN) and D-alanine sodium nitrate (DASN), were grown from an aqueous solution by slow-evaporation technique. X-ray diffraction (XRD) studies were carried for the doped grown crystals. The absorption of these grown crystals was analyzed using UV-Vis-NIR studies, and it was found that these crystals possess minimum absorption from 200 to 1100 nm. An infrared (FTIR) spectrum of single crystal has been measured in the 4000–400 cm−1 range. The assignment of the observed vibrational modes to corresponding symmetry type has been performed. A thermogravimetric study was carried out to determine the thermal properties of the grown crystal. The efficiency of second harmonic generation was obtained by a variant of the Kurtz-Perry method

In the Dark all Cats are Black

Photo-essay in Comparative Studies of South Asia, Africa and the Middle East. Special issue: Southern Futures

Disolución de hierro de un concentrado complejo de esfalerita por Acidithiobacillus ferrooxidans

En el presente trabajo se empleó una cepa de Acidithiobacillus ferrooxidans (Af) para biolixiviar el hierro pirítico presente en un concentrado de sulfuro de zinc con un contenido de 1,41% en peso de hierro. El proceso de biolixiviación se llevó a cabo en una suspensión conteniendo de 5 a 8% de sólidos p/v a un pH de alrededor de 2,7 (ajustado con ácido sulfúrico) y a una temperatura de 30 °C. Los resultados muestran que en un periodo de 15 días, el contenido metalúrgico del hierro disminuyó en un 17%, lo cual se traduce en un incremento en el grado metalúrgico del concentrado de zinc de 64,6 a 66,9%, lo que permitió incrementar  substancialmente el valor comercial de éste, evitando penalizaciones por el contenido de hierro presente

The cientificWorldJOURNAL Research Article An Optical Overview of Poly[µ 2 -L-alanine-µ 3 -nitrato-sodium(I)] Crystals

Single crystals of the semiorganic materials, L-alanine sodium nitrate (LASN) and D-alanine sodium nitrate (DASN), were grown from an aqueous solution by slow-evaporation technique. X-ray diffraction (XRD) studies were carried for the doped grown crystals. The absorption of these grown crystals was analyzed using UV-vis-NIR studies, and it was found that these crystals possess minimum absorption from 200 to 1100 nm. An infrared (FTIR) spectrum of single crystal has been measured in the 4000-400 cm −1 range. The assignment of the observed vibrational modes to corresponding symmetry type has been performed. A thermogravimetric study was carried out to determine the thermal properties of the grown crystal. The efficiency of second harmonic generation was obtained by a variant of the Kurtz-Perry method

Gene transfer into hepatocytes using asialoglycoprotein receptor mediated endocytosis of DNA complexed with an artificial tetra-antennary galactose ligand

We have constructed an artificial ligand for the hepatocyte-specific asialoglycoprotein receptor for the purpose of generating a synthetic delivery system for DNA. This ligand has a tetra-antennary structure, containing four terminal galactose residues on a branched carrier peptide. The carbohydrate residues of this glycopeptide were introduced by reductive coupling of lactose to the alpha- and epsilon-amino groups of the two N-terminal lysines on the carrier peptide. The C-terminus of the peptide, containing a cysteine separated from the branched N-terminus by a 10 amino acid spacer sequence, was used for conjugation to 3-(2-pyridyldithio)propionate-modified polylysine via disulfide bond formation. Complexes containing plasmid DNA bound to these galactose-polylysine conjugates have been used for asialoglycoprotein receptor-mediated transfer of a luciferase gene into human (HepG2) and murine (BNL CL.2) hepatocyte cell lines. Gene transfer was strongly promoted when amphipathic peptides with pH-controlled membrane-disruption activity, derived from the N-terminal sequence of influenza virus hemagglutinin HA-2, were also present in these DNA complexes. Thus, we have essentially borrowed the small functional domains of two large proteins, asialoglycoprotein and hemagglutinin, and assembled them into a supramolecular complex to generate an efficient gene-transfer system

Adaptation and validation of the Patient Expectations and Satisfaction with Prenatal Care instrument among Brazilian pregnant women

Objective: to adapt and validate the Patient Expectations and Satisfaction with Prenatal Care instrument for use in Brazil. It contains 41 items divided into two dimensions: expectations and satisfaction. The adapted version was submitted to analysis for stability, convergent construct validity, and internal consistency (Cronbach’s alpha) for distinct groups and dimensions. Method: 119 pregnant women receiving prenatal care were interviewed and 26 of these women answered the instrument twice (retest). Internal consistency was appropriate (Cronbach’s alpha ≥ 0.70); test-retest presented strong correlation (r=0.82; p<0.001) for the domain expectations and moderate correlation (r=0.66; p<0.001) for the satisfaction domain. The analysis confirmed that the instrument’s adapted version is valid in the studied group. Results: there is strong evidence for the validity and reliability of the instrument’s adaptation. Conclusion: the instrument needs to be tested in groups of pregnant women with different social characteristics.CAPESCAPE

Turning universal O into rare Bombay type blood

Red blood cell antigens play critical roles in blood transfusion since donor incompatibilities can be lethal. Recipients with the rare total deficiency in H antigen, the Oh Bombay phenotype, can only be transfused with group Oh blood to avoid serious transfusion reactions. We discover FucOB from the mucin-degrading bacteria Akkermansia muciniphila as an -1,2-fucosidase able to hydrolyze Type I, Type II, Type III and Type V H antigens to obtain the afucosylated Bombay phenotype in vitro. X-ray crystal structures of FucOB show a three-domain architecture, including a GH95 glycoside hydrolase. The structural data together with site-directed mutagenesis, enzymatic activity and computational methods provide molecular insights into substrate specificity and catalysis. Furthermore, using agglutination tests and flow cytometry-based techniques, we demonstrate the ability of FucOB to convert universal O type into rare Bombay type blood, providing exciting possibilities to facilitate transfusion in recipients/patients with Bombay phenotype

Meanings given to algebraic symbolism in problem posing

Some errors in the learning of algebra suggest students have difficulties giving meaning to algebraic symbolism. In this paper, we use problem posing in order to analyze the students’ capacity to assign meaning to algebraic symbolism and the difficulties that students encounter in this process depending on the characteristics of the algebraic statements given. We designed a written questionnaire composed of eight closed algebraic statements expressed symbolically, which was administered to 55 students who had finished their compulsory education and that had some previous experience in problem posing. In our analysis of the data, we examine both syntactic and semantic structures of the problem posed. We note that in most cases students posed problems with syntactic structures different to those given. They did not include computations within variables, and changed the kinds of relationships connecting variables. Students easily posed problems for statements with additive structures. Other differences in the type of problems posed depend on the characteristics of the given statements

Λειτουργική ανάλυση και χαρακτηρισμός στόχου εντομοκτόνων και πρωτεϊνών αποτοξικοποίησης σε επιβλαβή έντομα και φορείς ασθενειών

Τα επιβλαβή έντομα αποτελούν απειλή για τη δημόσια υγεία και την γεωργία καθώς μεταφέρουν εντομομεταδιδόμενες ασθένειες και καταστρέφουν τις καλλιέργειες. Η καταπολέμησή τους βασίζεται κυρίως στη χρήση χημικών εντομοκτόνων. Ωστόσο, η συχνή τους εφαρμογή έχει οδηγήσει σε πολλά προβλήματα, μεταξύ των οποίων η ανάπτυξη ανθεκτικότητας στα εντομοκτόνα – η οποία επιτυγχάνεται κυρίως μέσω της δράσης των ενζύμων αποτοξικοποίησης και μεταλλαγές στις πρωτεΐνες-στόχους των εντομοκτόνων – καθώς και επιδράσεις στην υγεία και το περιβάλλον. Έτσι, η κατανόηση των μηχανισμών που διέπουν την ανθεκτικότητα στα εντομοκτόνα καθώς και η ανάπτυξη νέων μεθόδων για την καταπολέμηση των εντόμων, πιο αποτελεσματικών, επιλεκτικών και φιλικών προς το περιβάλλον αποτελούν επείγουσα ανάγκη. Σε αυτήν την εργασία, χρησιμοποιήσαμε μοριακές τεχνικές, προσεγγίσεις για την έκφραση πρωτεϊνών καθώς και βιοχημικές/λειτουργικές μελέτες για α) τη διερεύνηση των μηχανισμών αποτοξικοποίησης εντομοκτόνων ουσιών σε κουνούπια-φορείς ανθρώπινων ασθενειών και β) την προσπάθεια λειτουργικής έκφρασης του ενζύμου απακετυλάση χιτίνης από παράσιτο της γεωργίας ώστε να μπορέσουμε να αξιολογήσουμε περαιτέρω το ρόλο του ενζύμου ως πιθανό στόχο για νέα παρασιτοκτόνα. Αρχικά, τρεις UGTs από κουνούπια-φορείς ανθρώπινων ασθενειών, οι οποίες έχουν συσχετιστεί με την ανθεκτικότητα σε εντομοκτόνα, κλωνοποιήθηκαν και εκφράστηκαν ετερόλογα σε κύτταρα εντόμων με τη χρήση του συστήματος έκφρασης με βακουλοϊούς και ελέγχθηκαν για την ικανότητά τους να γλυκοζυλιώνουν γνωστούς μεταβολίτες εντομοκτόνων. Από το κουνούπι Anopheles gambiae, τον κύριο φορέα της ελονοσίας, η πρωτεΐνη AgUGT1 η οποία έχει συσχετιστεί με την ανθεκτικότητα σε πυρεθροειδή εντομοκτόνα εκφράστηκε επιτυχώς και ελέγχτηκε ως προς την δράση της έναντι στους μεταβολίτες πυρεθροειδών: 3-φαινοξυβένζυλ αλκοόλη (PBAlc) και 3-φαινοξυβενζοϊκό οξύ (ΡΒΑ). Οι πρωτεΐνες Aealbo_UGT1 και Aealbo_UGT2 από το ασιατικό κουνούπι τίγρης Aedes albopictus, φορέα ιών όπως ο δάγκειος πυρετός, οι οποίες έχουν συσχετιστεί με την ανθεκτικότητα στο οργανοφωσφορικό εντομοκτόνο τέμεφος, εκφράστηκαν επιτυχώς και όπως η AgUGT1, έδειξαν ενεργότητα γλυκοζυλτρανσφεράσης προς το ένα γενικό υπόστρωμα για τις UGTs, το a-naphthol. Στο δεύτερο κεφάλαιο, προσπαθήσαμε να εκφράσουμε και να χαρακτηρίσουμε λειτουργικά μια πιθανή απακετυλάση χιτίνης από το σκουλήκι του βαμβακιού Helicoverpa armigera ώστε να την μελετήσουμε περαιτέρω ως πιθανό στόχο για τον σχεδιασμό και την ανάπτυξη νέων φυτοφαρμάκων.Insect pests are major threats for public health and agriculture, as they transmit various diseases and attack agricultural crops. Their control has been largely relied on the use of chemical insecticides. However their intensive use has resulted in many problems including the development of resistance – mainly achieved by detoxification enzymes and target site resistance mutations – effects in human health and environmental impacts. Thus, understanding the mechanisms underlying insecticide resistance as well as developing novel ways for insect control, more efficient, selective and environmentally safe are a clear and urgent need. In this thesis, we used techniques of molecular biology, protein expression approaches and biochemical/functional techniques to a) investigate detoxification mechanisms of major mosquito vectors against insecticides and b) attempt to functionally express a pest chitin deacetylase to further evaluate it as a potential target for novel pesticides. First, three mosquito UGTs, previously associated with insecticide resistance in two major vectors of human diseases, were cloned and expressed in insect cells using the baculovirus expression system and were tested for their ability to glycosylate known insecticide metabolites. AgUGT1 from Anopheles gambiae, the major malaria vector, associated with resistance to insecticides of the pyrethroid class, were functionally expressed and tested for their activity towards the pyrethroid metabolites 3-Phenoxybenzyl alcohol (PBAlc) and 3-Phenoxybenzoic acid (PBA). Aealbo_UGT1 and Aealbo_UGT2 from Aedes albopictus, the Asian Tiger mosquito, vector of arboviruses such as dengue, associated with resistance to the organophosphate temephos were expressed and, as well as AgUGT1, were active showing glucosyltransferase activity towards the common UGT substrate a-naphthol. In the second chapter, we tried to express and characterize a possible chitin deacetylase from the cotton bollworm Helicoverpa armigera to further study it as a possible target for the design and development of novel pesticides