Développement d’une lentille cornéenne médicamentée

L’utilisation de lentilles cornéennes peut servir à améliorer le profil d’administration d’un principe actif dans les yeux. Avec une efficacité d’administration de 5% par l’utilisation de gouttes, on comprend rapidement que l’administration oculaire doit être améliorée. Cette faible administration a donné naissance à plusieurs tentatives visant à fabriquer des lentilles cornéennes médicamentées. Cependant, à cause de multiples raisons, aucune de ces tentatives n’a actuellement été mise sur le marché. Nous proposons dans cette étude, une possible amélioration des systèmes établis par le développement d’une lentille cornéenne à base de 2-(hydroxyéthyle)méthacrylate (HEMA), dans laquelle des microgels, à base de poly N-isopropylacrylamide (pNIPAM) thermosensible encapsulant un principe actif, seront incorporé. Nous avons donc débuté par développer une méthode analytique sensible par HPCL-MS/MS capable de quantifier plusieurs molécules à la fois. La méthode résultante a été validée selon les différents critères de la FDA et l’ICH en démontrant des limites de quantifications et de détections suffisamment basses, autant dans des fluides simulés que dans les tissus d’yeux de lapins. La méthode a été validée pour sept médicaments ophtalmiques : Pilocarpine, lidocaïne, proparacaïne, atropine, acétonide de triamcinolone, timolol et prednisolone. Nous avons ensuite fait la synthèse des microgels chargés négativement à base de NIPAM et d’acide méthacrylique (MAA). Nous avons encapsulé une molécule modèle dans des particules ayant une taille entre 200 et 600 nm dépendant de la composition ainsi qu’un potentiel zêta variant en fonction de la température. L’encapsulation de la rhodamine 6G (R6G) dans les microgels a été possible jusqu’à un chargement (DL%) de 38%. L’utilisation des isothermes de Langmuir a permis de montrer que l’encapsulation était principalement le résultat d’interactions électrostatiques entre les MAA et la R6G. Des cinétiques de libérations ont été effectuées à partir d’hydrogels d’acrylamide chargés en microgels encapsulant la R6G. Il a été trouvé que la libération des hydrogels chargés en microgels s’effectuait majoritairement selon l’affinité au microgel et sur une période d’environ 4-24 heures. La libération à partir de ces systèmes a été comparée à des formules d’hydrogels contenant des liposomes ou des nanogels de chitosan. Ces trois derniers (liposomes, microgels et nanogels) ont présenté des résultats prometteurs pour différentes applications avec différents profils de libérations. Enfin, nous avons transposé le modèle développé avec les gels d’acrylamide pour fabriquer des lentilles de contact de 260 à 340 µm d’épaisseur à base de pHEMA contenant les microgels avec une molécule encapsulée devant être administrée dans les yeux. Nous avons modifié la composition de l’hydrogel en incorporant un polymère linéaire, la polyvinylpyrrolidone (PVP). L’obtention d’hydrogels partiellement interpénétrés améliore la rétention d’eau dans les lentilles cornéennes. L’encapsulation dans les microgels chargés négativement a donné de meilleurs rendements avec la lidocaïne et cette dernière a été libérée de la lentille de pHEMA en totalité en approximativement 2 heures qu’elle soit ou non encapsulée dans des microgels. Ainsi dans cette étude pilote, l’impact des microgels n’a pas pu être déterminé et, de ce fait, nécessitera des études approfondies sur la structure et les propriétés de la lentille qui a été développée. En utilisant des modèles de libération plus représentatifs de la physiologie de l’œil, nous pourrions conclure avec plus de certitude concernant l’efficacité d’un tel système d’administration et s’il est possible de l’optimiser.

(Table T2) Relative signal intensity of intact polar lipids in sediments from ODP Sites 207-1257 and 207-1258

We report results from the analysis of intact polar lipids (IPLs) in sediments from Ocean Drilling Program Sites 1257 and 1258. IPLs, constituting the cell membranes of living organisms, were detected in organic-lean sediments but not in underlying organic-rich black shales. Microbial activity in organic-lean sediments is likely due to sulfate-dependent oxidation of methane whereas difficulties detecting IPLs in black shales are interpreted to result from unfavorable signal-to-noise ratios due to low cell concentrations in combination with extremely high analytical noise created by uncharacterized organic matrix. IPLs found are consistent with a low-diversity community of archaea and bacteria. The concentrations of IPLs are more than one order of magnitude lower than those in Neogene deep subsurface sediments at the Peruvian margin, suggestive of significantly lower cell concentrations in Demerara Rise. This finding is consistent with inferred low rates of subsurface microbial activity.

(Table 1) TOC content, BIT, TEX86 and UK'37 indices, and sea surface temperature reconstruction for the middle Miocene to Pliocene of ODP Hole 175-1085A

The initiation of the Benguela upwelling has been dated to the late Miocene, but estimates of its sea surface temperature evolution are not available. This study presents data from Ocean Drilling Program (ODP) Site 1085 recovered from the southern Cape Basin. Samples of the middle Miocene to Pliocene were analyzed for alkenone-based (UK'37, SSTUK) and glycerol dialkyl glycerol tetraether (GDGT) based (TEX86, TempTEX) water temperature proxies. In concordance with global cooling during the Miocene, SSTUK and TempTEX exhibit a decline of about 8°C and 16°C, respectively. The temperature trends suggest an inflow of cold Antarctic waters triggered by Antarctic ice sheet expansion and intensification of Southern Hemisphere southeasterly winds. A temperature offset between both proxies developed with the onset of upwelling, which can be explained by differences in habitat: alkenone-producing phytoplankton live in the euphotic zone and record sea surface temperatures, while GDGT-producing Thaumarchaeota are displaced to colder subsurface waters in upwelling-influenced areas and record subsurface water temperatures. We suggest that variations in subsurface water temperatures were driven by advection of cold Antarctic waters and thermocline adjustments that were due to changes in North Atlantic deep water formation. A decline in surface temperatures, an increased offset between temperature proxies, and an increase in primary productivity suggest the establishment of the Benguela upwelling at 10 Ma. During the Messinian Salinity Crisis, between 7 and 5 Ma, surface and subsurface temperature estimates became similar, likely because of a strong reduction in Atlantic overturning circulation, while high total organic carbon contents suggest a "biogenic bloom." In the Pliocene the offset between the temperature estimates and the cooling trend was reestablished.

Prétraitement d'un isolat de protéines de lin par haute pression hydrostatique : impacts sur la structure protéique, l'hydrolyse enzymatique et les capacités antioxydantes des hydrolysats finaux

Les graines de lin sont des oléagineux largement cultivés au Canada. Cependant, les résidus générés suite au processus d’extraction de l’huile contiennent une importante quantité de protéines et peuvent être valorisées dans l’alimentation humaine en raison, principalement, de certaines fractions peptidiques possédant des propriétés bioactives. Dans le cadre de ce travail, l’influence des hautes pressions hydrostatiques (HPH) sur un isolat de protéines de lin a été étudiée concernant les modifications de la structure protéique, l’hydrolyse enzymatique ainsi que l’activité antioxydante des hydrolysats. Ainsi, des solutions protéiques de lin (1% m/v) ont été soumises à un traitement de HPH à 600 MPa pendant 5 et 20 minutes, à 20°C et comparés à des échantillons non-pressurisés. Deux traitements subséquents d’hydrolyse ont été effectués suite au traitement ou non de pressurisation : une première hydrolyse trypsique suivie d’une deuxième par la pronase. Dans un premier temps, la caractérisation de l’isolat protéique de lin pressurisé et non pressurisé a été réalisée par spectrofluorimétrie et par une analyse de la taille des particules afin d’étudier l’effet de la pressurisation sur les HPH la matrice protéique végétale. Par la suite, les hydrolysats protéiques ont été caractérisés par HPLC-MS et leur capacité antioxydante a été déterminée par ORAC. Les résultats ont démontré que le niveau de pressurisation et la durée du traitement ont un impact sur la structure protéique en induisant la dissociation des protéines, et la formation d’agrégats. Ceux-ci seraient occasionnés par la décompression ou créés durant l’entreposage des isolats. Suite à l’hydrolyse enzymatique des solutions protéiques pressurisées ou non par la trypsine seule et par la trypsine-pronase, les analyses chromatographiques ont révélé que la concentration de certains peptides a été modifiée lorsque la trypsine seule était utilisée après un traitement à HPH. Enfin, les HPH ont amélioré la capacité antioxydante des hydrolysats obtenus lors de l’hydrolyse trypsine-pronase comparativement au contrôle non-pressurisé.

Prospeção de compostos bioativos nas macroalgas Himanthalia elongata, Laminaria ochroleuca e Undaria pinnatifida

O presente trabalho teve como principal objetivo caracterizar os metabolitos secundários, compostos lipofílicos e compostos mais polares, de três macroalgas existentes na costa portuguesa, nomeadamente da H. elongata, L. ochroleuca e U. pinnatifida, de forma a contribuir para a sua valorização. Foram realizadas extrações Soxhlet com diclorometano para extrair os compostos lipofílicos, enquanto as frações mais polares foram obtidas por extrações convencionais sólido-líquido, usando diferentes misturas de solventes (acetona:H2O e metanol:H2O:AcOH). Os extratos foram analisados por GC-MS e HPLC-MS. Os extratos polares foram ainda avaliados quanto à sua atividade antioxidante e quanto ao teor de fenóis totais (método de Folin-Ciocâlteau) e florotaninos (método DMBA). A fração lipofílica das três macroalgas estudadas é composta principalmente por ácidos gordos, álcoois alifáticos de cadeia longa e esteróis. O ácido hexadecanóico mostrou ser o composto maioritário das três espécies de algas, seguido dos ácidos octadeca-9-enóico e tetradecanóico. O fucosterol foi o esterol mais abundante encontrado para a H. elongata, enquanto que na L. ochroleuca e na U. pinnatifida foi o 24-metilenocolesterol. Os extratos polares obtidos a partir das duas metodologias de extração apresentaram rendimentos de extração elevados, tendo os extratos acetona:H2O apresentado rendimentos de extração superiores (88.73-92.33 %). Estes extratos mostraram ainda teores de fenóis e florotaninos totais mais elevados, com valores entre 524.03-635.69 g EAG/kg de peso seco e 1.48-1.55 g EFG/kg de peso seco, respetivamente. Os extratos de acetona:H2O no ensaio DPPH apresentaram valores de IC50 entre 6.57-7.64 μg/mL. Estes valores, apesar de serem inferiores ao IC50 do ácido ascórbico, são superiores ao determinado para o antioxidante sintético butil-hidroxitolueno (BHT). O extrato da acetona:H2O da L. ochroleuca foi o que apresentou melhor atividade antioxidante, com um IC50 de 6.57 ± 0.71 μg/mL. A análise por HPLC-DAD-MSn não permitiu até ao momento detetar compostos fenólicos nos extratos obtidos. Estes resultados são uma contribuição relevante para a valorização destas espécies de macroalgas como fonte de fitoquímicos valiosos.

Chemical characterization and evaluation of biological activity of Cynara cardunculus extractable compounds

The Mediterranean species Cynara cardunculus L. is recognized in the traditional medicine, for their hepatoprotective and choleretic effects. Biomass of C. cardunculus L. var. altilis (DC), or cultivated cardoon, may be explored not only for the production of energy and pulp fibers, but also for the extraction of bioactive compounds. The chemical characterization of extractable components, namely terpenic and phenolic compounds, may valorize the cultivated cardoon plantation, due to their antioxidant, antitumoral and antimicrobial activities. In this study, the chemical composition of lipophilic and phenolic fractions of C. cardunculus L. var. altilis (DC), cultivated in the south of Portugal (Baixo Alentejo region) was characterized in detail, intending the integral valorization of its biomass. The biological activity of cultivated cardoon extracts was evaluated in terms of antioxidant, human tumor cell antiproliferative and antibacterial effects. Gas chromatography-mass spectrometry (GC-MS) was used for the chemical analysis of lipophilic compounds. Sixty-five lipophilic compounds were identified, from which 1 sesquiterpene lactone and 4 pentacyclic triterpenes were described, for the first time, as cultivated cardoon components, such as: deacylcynaropicrin, acetates of β- and α-amyrin, lupenyl acetate and ψ-taraxasteryl acetate. Sesquiterpene lactones were the major family of lipophilic components of leaves (≈94.5 g/kg), mostly represented by cynaropicrin (≈87.4 g/kg). Pentacyclic triterpenes were also detected, in considerably high contents, in the remaining parts of cultivated cardoon, especially in the florets (≈27.5 g/kg). Taraxasteryl acetate was the main pentacyclic triterpene (≈8.9 g/kg in florets). High pressure liquid chromatography-mass spectrometry (HPLC-MS) was utilized for the chemical analysis of phenolic compounds. Among the identified 28 phenolic compounds, eriodictyol hexoside was reported for the first time as C. cardunculus L. component, and 6 as cultivated cardoon components, namely 1,4-di-O-caffeoylquinic acid, naringenin 7-O-glucoside, naringenin rutinoside, naringenin, luteolin acetylhexoside and apigenin acetylhexoside. The highest content of the identified phenolic compounds was observed in the florets (≈12.6 g/kg). Stalks outer part contained the highest hydroxycinnamic acids abundance (≈10.3 g/kg), and florets presented the highest flavonoids content (≈10.3 g/kg). The antioxidant activity of phenolic fraction was examined through 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Stalks outer part, and receptacles and bracts extracts demonstrated the highest antioxidant effect on DPPH (IC50 of 34.35 μg/mL and 35.25 μg/mL, respectively). (cont.) abstract (cont.) The DPPH scavenging effect was linearly correlated with the total contents of hydroxycinnamic acids (r = -0.990). The in vitro antiproliferative activity of cultivated cardoon lipophilic and phenolic extracts was evaluated on a human tumor cells line of triple-negative breast cancer (MDA-MB-231), one of the most refractory human cancers to conventional therapeutics. After 48 h of exposition, leaves lipophilic extract showed higher inhibitory effect (IC50 = 10.39 μg/mL) than florets lipophilic extract (IC50 = 315.22 μg/mL), upon MDA-MB-231 cellular viability. Pure compound of cynaropicrin, representative of the main compound identified in leaves lipophilic extract, also prevented the cell proliferation of MDA-MB-231 (IC50 = 17.86 μM). MDA-MB-231 cells were much more resistant to the 48 h- treatment with phenolic extracts of stalks outer part (IC50 = 3341.20 μg/mL) and florets (IC50 > 4500 μg/mL), and also with the pure compound of 1,5-di-O-caffeoylquinic acid (IC50 = 1741.69 μM). MDA-MB-231 cells were exposed, for 48 h, to the respective IC50 concentrations of leaves lipophilic extract and pure compound of cynaropicrin, in order to understand their ability in modelling cellular responses, and consequently important potentially signaling pathways for the cellular viability decrease. Leaves lipophilic extract increased the caspase-3 enzymatic activity, contrarily to pure compound of cynaropicrin. Additionally, leaves lipophilic extract and pure compound of cynaropicrin caused G2 cell cycle arrest, possibly by upregulating the p21Waf1/Cip1 and the accumulation of phospho-Tyr15-CDK1 and cyclin B1. The inhibitory effects of leaves lipophilic extract and cynaropicrin pure compound, against the MDA-MB-231 cell proliferation, may also be related to the downregulation of phospho-Ser473-Akt. The antibacterial activity of cultivated cardoon lipophilic and phenolic extracts was assessed, for the first time, on two multidrug-resistant bacteria, such as the Gram-negative Pseudomonas aeruginosa PAO1 and the Gram-positive methicillin-resistant Staphylococcus aureus (MRSA), two of the main bacteria responsible for health care-associated infections. Accordingly, the minimum inhibitory concentrations (MIC) were determined. Lipophilic and phenolic extracts of florets did not have antibacterial activity on P. aeruginosa PAO1 and MRSA (MIC > 2048 μg/mL). Leaves lipophilic extract did not prevent the P. aeruginosa PAO1 growth, but pure compound of cynaropicrin was slightly active (MIC = 2048 μg/mL). Leaves lipophilic extract and pure compound of cynaropicrin blocked MRSA growth (MIC of 1024 and 256 μg/mL, respectively). The scientific knowledge revealed in this thesis, either by the chemical viewpoint, or by the biological viewpoint, contributes for the valorization of C. cardunculus L. var. altilis (DC) biomass. Cultivated cardoon has potential to be exploited as source of bioactive compounds, in conciliation with other valorization pathways, and Portuguese traditional cheeses manufacturing.

Caractérisation des effets de l’hyperglycémie chronique dans la choroïde d’yeux diabétiques

But: Le diabète est un problème important de santé publique et la complication oculaire la plus commune est la rétinopathie diabétique (RD). Certaines études indiquent que la choroïde des patients diabétiques est affectée sans signe apparent de RD. Notre hypothèse est que l’élévation du stress oxydant liée à l’hyperglycémie chronique affecte la fonction choroïdienne à un stade précoce de la RD. Nous proposons d’étudier la glycolyse, le métabolisme mitochondrial, le stress nitrosatif et la méthylation de l’ADN ainsi que de caractériser les modifications histologiques dans la choroïde diabétique. Méthodes: L’expression des gènes/protéines associés à la glycolyse, au métabolisme mitochondrial et à la production de l’oxyde nitrique a été comparée par profilage génique et immunobuvardage Western entre les choroïdes saines et diabétiques. Les niveaux globaux de méthylation et d’hydroxyméthylation de l’ADN ont été quantifiés par immunoslot blot et HPLC-MS/MS dans ces tissus. Enfin, des coupes tissulaires d’yeux de donneurs sains ou diabétiques avec RD non proliférante (RDNP) ou proliférante (RDP) ont été colorées au trichrome de Masson et au Weigert. L’épaisseur de la choroïde et de la membrane de Bruch, ainsi que la densité et le diamètre des vaisseaux sanguins choroïdiens ont été analysés. Résultats: Nos résultats montrent une dérégulation de l’expression de certains transcrits de la choroïde diabétique, mais peu de différences au niveau de l’expression protéique des cibles validées. Le niveau global de méthylation de l’ADN est similaire entre les donneurs sains et diabétiques. Nos analyses histologiques démontrent une diminution de l’épaisseur de la choroïde et une dégénérescence des choriocapillaires et des veines/veinules chez les donneurs diabétiques atteints de RDP. Conclusions: L’étude de la choroïde est importante, car l’atteinte de ce tissu a de graves répercussions sur la fonction rétinienne. L’identification de cibles dans la choroïde ouvre de nouvelles perspectives pour un traitement préventif de la RD.

Połączenia krzyżowe pochodnych cysteiny z aldehydowymi adduktami nukleozydów adeninowych

Wydział Chemii

Foto-oxidación de bisfenol A bajo la acción de luz visible: el monitoreo de oxígeno disuelto como evidencia de la degradación

Propósito y Método del Estudio: El semiconductor más utilizado para su uso en fotocatálisis es el TiO2 debido a sus características como bajo costo, inocuidad y eficiencia fotocatalítica; alguno de los inconvenientes del uso de este material es su capacidad de activarse con radiación UV. En el presente trabajo se modificó al catalizador TiO2 con N a través del método de síntesis coloidal con el propósito de hacerlo fotoactivo bajo radiación visible; se sintetizaron catalizadores modificados a diferentes cantidades teóricas de nitrógeno, los cuales se caracterizaron morfológica y estructuralmente; posteriormente se evaluó la actividad fotocatalítica, bajo radiación visible con una solución de Bisfenol A realizando el seguimiento de la degradación fotocatalítica mediante espectroscopia UV-Vis y cromatografía de líquidos de alta resolución acoplado a espectrometría de masas (HPLC-MS). Contribuciones y Conclusiones: los resultados confirmaron que la incorporación de Nitrógeno al TiO2 provoca cambios en la cristalinidad, morfología y área superficial, así como en su actividad con radiación visible. La evolución fotocatalitica demostró que el catalizador modificado con 5% fue el que presento mayor eficiencia en la degradación de Bisfenol A.

Francisco Pizarro' s banner of arms: an analytical work contributing to latin America's history

The study of textiles is an open area of scientific research, which for its variety of material components and physical chemical diversity of conditions, makes a field of interest for scientific studies in the cultural heritage field. Archaeological/historical textiles offer the possibility to carry out studies on organic materials such as fibers, adhesion elements, dyes, paper, etc., as well as on inorganic compounds for instance metals, alloys, precious stones and other added ornamentation. That variety of composition, allow to use a combination of analytical techniques to solve the questions coming from the object in an archaeometric research. One kind of textile object that provides a valuable cultural information because of its linguistic representation employed by its carrier societies, are the flags/banners/emblems, objects made with a nonverbal communication purpose. As long as depending on the use and/or purpose of each object, varies both the materials/techniques used in its production and its iconography (style, color, emblem, shape), its study gives the possibility to extract information through their materials and manufacturing techniques about a temporal-spatial frame, a particular event or a specific character. The flags/banners have been used since the eleventh century as representative objects of power, hierarchy, social or military organization, or as communicative media. The use of these objects has been spread throughout the world, possibly due to its easy interpretation and/or appropriation by different societies, making it part of their own culture. The flags as symbols of territorial control, using emblems that represent a family, order or army, were introduced to the New World (America) with the arrival of the European conquerors at the end of the fifteenth century. Flags/banners representing the Royal dominion over conquered territories, the Catholic Church and conquistadors’ armies were the first to arrive. One of those flags that have endured over time, that have an invaluable cultural meaning for both American and Iberian societies, is the so-called Francisco Pizarro’s Banner of Arms. It is a textile object with metal threads decoration over a Royal emblem. According to historical sources, this object was used by Francisco Pizarro in 1532 on the conquest process of Peru, after received the permission by King Charles V to on behalf of him, to conquer the lands of the New World today known as Peru. After Pizarro’s control of the Inca territory, it is believed that Pizarro left his banner on top of the Inca’s Sun’s Temple as symbol of his rule. Centuries later, in the America libertarian campaigns, General Sucre, military at charge of the independence army in Peru, reports have found what he considered the Pizarro’s Banner, sending it to Bogotá as a symbol of victory, being kept since that time until today by the National Museum of Colombia. Due to historical discrepancies in the different movements of the so-called Pizarro’s Banner of Arms, its real meaning has been under discussion and because of the passage of time its physical condition has suffer deterioration. That is because its scientific study is now an interesting case study to respond to both historical and conservation questions of it. Through a collaboration with the National Museum of Colombia, a set of 25 samples of so-called Pizarro’s Banner of Arms were collected, covering the various components and areas from the object of study. These samples were subjected to analytical studies for physical and chemical characterization. Microscopic observation, VSEM-EDS analysis, Raman spectroscopy, chromatographic analysis (HPLC-MS, GCMS) and radiocarbon dating were done. Similarly, was sought through a direct in situ physical inspection to the object and through a research into historical sources, adequate information to solve the object’s problems. Results obtained allowed to identify as silk the textile used in the elaboration of the Banner’s fabric, as well as the use of natural dyes for dyeing the fibers used on the emblem: use of cochineal and brazil wood as a source of red, luteolin plant-based for yellow color, indigotine plant-based for blue, and a mixture of yellow and blue dyes for green were identified. Similarly, the use of animal glue in the manufacturing process and the use of rag paper was evident. The metal threads study from the Banner give a confirmation to a silver core wire gilded with a thin gold sheet, being flattened and entwined with silk threads for their use. Finally, using the radiocarbon results, it was possible to postulate with huge accuracy that the Banner date manufacture was between the XV-XVI century and subject to restoration processes with addition of textiles in modern times. Together with, was evident that the state of degradation of the fabric is due to natural degradation in the silk fibers, having that its color has faded and its mechanical properties decreased, leading to loss of rigidity and disappearance of the physical structure. Similarly, it was clear the original colors of the emblem and highlight problems of detachment of paper due to crystallization of the adhesive. In the same way, was found that the metal threads suffer corrosion by sulfur and detachment of its crystals. Finally, combining the analytical results and the historical sources data found from the so-called Francisco Pizarro’s Banner of Arms, allows to postulate that its manufacture process was done in Europe employing precious materials to obtain a long-life object with a deep message for its viewers. Also, the data obtained helps to support the possible idea that the object was employed by Francisco Pizarro in the Peru conquest process. However, by the symbols present in the object, its elaboration date and materials, this object its clearly unique in its kind, and the most important, by its linguistic message, does not represent to Francisco Pizarro or his army, meanwhile, represents the Spanish crown. Therefore, instead to be labeled as Francisco Pizarro’s Banner of Arms, it should be called the Colonial Royal Banner of Charles V in the New World; RESUMEN: El estudio de textiles es un área abierta de investigación científica, la cual por su variedad de componentes materiales y la diversidad de condiciones físico-químicas presentes en estos objetos, lo hace un campo de interés para estudios científicos en el patrimonio cultural. Los textiles arqueológicos/históricos brindan la posibilidad de realizar estudios en materiales orgánicos como fibras, elementos de adhesión, tinturas, papel, etc., e inorgánicos como metales, aleaciones, piedras preciosas y demás materiales decorativos añadidos. Por su variedad de composición, es posible emplear diversas técnicas analíticas para resolver aquellas preguntas propias del objeto en una investigación arqueométrica. Uno de los objetos textiles que brinda gran información cultural debido a su representación lingüística empleada por las sociedades portadoras, son las banderas/estandartes/emblemas. Donde varía dependiendo de su uso y/o propósito, los materiales empleados en su elaboración, al igual que su iconografía (estilo, color, emblema, forma). El estudio de estos objetos construidos con un propósito de comunicación no verbal, da la posibilidad de extraer información a través de sus materiales y técnicas de elaboración sobre un rango temporal-espacial, un evento determinado en la historia o incluso a un personaje en específico. Las banderas han sido empleadas desde el siglo XI como objetos representativos de poder, jerarquía, organización social o militar, o como medio de comunicación. El uso de estos objetos se ha extendido a lo largo del mundo posiblemente debido a su fácil interpretación y/o apropiación por distintas sociedades, haciéndolo parte de su cultura. Las banderas como símbolos de control territorial, empleando símbolos que representan a una familia, orden o armada fueron introducidas a el Nuevo Mundo (América) con la llegada de los conquistadores europeos al final del siglo XV. Las banderas/estandartes que representaban el dominio Real sobre territorios dominados, la iglesia católica y las banderas de ejércitos y/o conquistadores fueron las primeras en llegar al nuevo mundo. Una de aquellas banderas que ha soportado el paso del tiempo, teniendo un gran valor cultural tanto para las sociedades americanas como para las ibéricas, es el denominado Estandarte de armas de Francisco Pizarro. Siendo un objeto textil con decoración en hilos metálicos sobre un emblema Real. De acuerdo a fuentes históricas, este objeto fue usado por Francisco Pizarro en 1532 en el proceso de conquista del Perú, quien recibe por parte del Rey Carlos V el poder para que, en su nombre, Pizarro pueda conquistar las tierras del nuevo mundo hoy conocidas como Perú. Luego del dominio de Pizarro sobre el territorio Inca, se cree que Pizarro dejó su estandarte en la cima del templo Inca del sol como símbolo de su control. Siglos más tarde, en las campañas libertarias de América, el General Sucre, militar encargado de la armada independentista en Perú, reporta haber encontrado lo que él considera como el estandarte de Pizarro, enviándolo a Bogotá como muestra de victoria, siendo custodiada desde ese momento por el Museo Nacional de Colombia hasta la actualidad. Debido a discrepancias históricas, el verdadero significado del llamado estandarte de Pizarro ha sido objeto de discusión y debido del pasar del tiempo su estado de conservación se ha deteriorado. Dejando de este modo, un caso de estudio interesante para que por medio de estudios científicos al objeto se pueda dar respuesta a preguntas tanto históricas como de conservación del mismo. De este modo, por medio de una colaboración con el Museo Nacional de Colombia, se obtuvo un juego de 25 muestras del llamado Estandarte de armas de Francisco Pizarro, abarcando los diferentes componentes y áreas del objeto de estudio. Dichas muestras fueron sometidas a estudios analíticos para su caracterización físico-química. Análisis de observación al microscopio, análisis VSEM-EDS, espectroscopia Raman, análisis cromatográficos (HPLC-MS, GC-MS) y datación por radiocarbono catorce fueron realizados. Del mismo modo, por medio de una inspección física al objeto in situ y una profunda investigación en fuentes históricas del mismo, se buscó la información adecuada para resolver sus problemáticas. Los resultados obtenidos permitieron identificar como seda el textil empleado en la elaboración del estandarte, así como el uso de colorantes naturales para teñir las fibras en el emblema: uso de cochinilla y palo de Brasil como fuente del color rojo, plantas a base de luteolin para el color amarillo, plantas a base de indigotina para el color azul y mezcla de colorantes amarillos y azules para el color verde fueron identificadas. Del mismo modo se evidencio el uso de adhesivos animales y el uso de papel de trapos en el proceso de manufactura. El estudio de los hilos metálicos, permitió evidenciar el uso de alambres con núcleos de plata con un fino recubrimiento de oro en su exterior, siendo aplanados y entrelazados con hilos de seda para su uso. Finalmente usando la datación por radiocarbono, fue posible conocer con alta precisión que el estandarte fue elaborado entre los siglos XV-XVI y sufrió procesos de restauración con añadidura de textiles en tiempos modernos. Junto a lo anterior, es posible postular que el estado de degradación de la tela es debido a degradación natural en las fibras de seda, teniendo así que su color se ha desvanecido y sus propiedades mecánicas disminuidas, conllevando a perdida de rigidez y desaparición de la estructura. Del mismo modo se pudo conocer los colores originales del emblema y evidenciar problemas de desprendimiento del papel debido a cristalización del adhesivo. Asimismo, se comprobó que los hilos metálicos presentan corrosión por azufre y desprendimiento de sus cristales. Finalmente, combinando los resultados analíticos y la información de fuentes históricas encontradas del llamado Estandarte de armas de Francisco Pizarro, se puede postular que su elaboración fue realizada en Europa, usando materiales preciosos para obtener un objeto de larga vida con un profundo mensaje para sus observadores. También, los datos obtenidos ayudan a dar soporte la posible idea de que este objeto fue usado por Francisco Pizarro en el proceso de conquista del Perú. Sin embargo, debido a los símbolos presentes en el objeto, fecha y materiales de elaboración, este objeto es claramente único en su tipo, y lo más importante, por su mensaje lingüístico, este no representa a Francisco Pizarro o su armada, al contrario, representa a la Corona de España. Por ende, en vez de denominarse como Estandarte de armas de Francisco Pizarro, este objeto debería nombrarse como el Estandarte Real de la Colonia de Carlos V en el Nuevo Mundo.

Combining HPLC-DAD and ICP-MS data for improved analysis of complex samples: Classification of the root samples from Cortex moutan

A combined data matrix consisting of high performance liquid chromatography–diode array detector (HPLC–DAD) and inductively coupled plasma-mass spectrometry (ICP-MS) measurements of samples from the plant roots of the Cortex moutan (CM), produced much better classification and prediction results in comparison with those obtained from either of the individual data sets. The HPLC peaks (organic components) of the CM samples, and the ICP-MS measurements (trace metal elements) were investigated with the use of principal component analysis (PCA) and the linear discriminant analysis (LDA) methods of data analysis; essentially, qualitative results suggested that discrimination of the CM samples from three different provinces was possible with the combined matrix producing best results. Another three methods, K-nearest neighbor (KNN), back-propagation artificial neural network (BP-ANN) and least squares support vector machines (LS-SVM) were applied for the classification and prediction of the samples. Again, the combined data matrix analyzed by the KNN method produced best results (100% correct; prediction set data). Additionally, multiple linear regression (MLR) was utilized to explore any relationship between the organic constituents and the metal elements of the CM samples; the extracted linear regression equations showed that the essential metals as well as some metallic pollutants were related to the organic compounds on the basis of their concentrations

Determinations of residual furazolidone and its metabolite, 3-amino-2-oxazolidinone (AOZ), in fish feeds by HPLC-UV and LC-MS/MS, respectively

The antibacterial drug furazolidone belonging to the group of nitrofuran antibacterial agents has been widely used as an antibacterial and antiprotozoal feed additive for poultry, cattle, and farmed fish in China. During application a large proportion of the administered drug may reach the environment directly or via feces. Although the use of furazolidone is prohibited in numerous countries, there are indications of its illegal use. It is known that furazolidone can be rapidly metabolized to 3-amino-2-oxazolidinone (AOZ) in the body of the target organism. In this study, a total of 21 fish feed samples, including 17 commercial fish feeds from local markets in China (representing 15 different formulations) and 4 fish feeds obtained from Germany and Turkey, respectively, are analyzed to determine whether the drug is still illegally used or commercially available feeds are contaminated by this drug. High-performance liquid chromatography (HPLC) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methods have been implemented to determine furazolidone and its metabolite AOZ in fish feeds containing animal protein, respectively. An efficient and convenient cleanup method for the determination of furazolidone in fish feeds is developed, and a simple cleanup method for the determination of AOZ is used. Method recoveries for samples used were determined as 87.7-98.3% for furazolidone at two spike levels of 2.0 and 5.0 ng g(-1) and as 95.6-102.8% for AOZ at spike levels of 0.4 and 0.8 ng g(-1). Limits of detections were 0.4 ng g(-1) for furazolidone and 0.05 ng g(-1) for AOZ. The established methods are therefore suitable for the determination of furazolidone and its metabolite AOZ in fish feeds at trace contamination levels. Using the established methods, all fish feed samples have been proved to be furazolidone negative; however, AOZ is tested in 16 of 17 fish feeds obtained from local markets in the Hubei province of China, with a positive rate as high as 94.1%.