New multivalent calixarene-based ligands for protein recognition and inhibition

One of the challenges that concerns chemistry is the design of molecules able to modulate protein-protein and protein-ligand interactions, since these are involved in many physiological and pathological processes. The interactions occurring between proteins and their natural counterparts can take place through reciprocal recognition of rather large surface areas, through recognition of single contact points and single residues, through inclusion of the substrates in specific, more or less deep binding sites. In many cases, the design of synthetic molecules able to interfere with the processes involving proteins can benefit from the possibility of exploiting the multivalent effect. Multivalency, widely spread in Nature, consists in the simultaneous formation between two entities (cell-cell, cell-protein, protein-protein) of multiple equivalent ligand-recognition site complexes. In this way the whole interaction results particularly strong and specific. Calixarenes furnish a very interesting scaffold for the preparation of multivalent ligands and in the last years calixarene-based ligands demonstrated their remarkable capability to recognize and inhibit or restore the activity of different proteins, with a high efficiency and selectivity in several recognition phenomena. The relevance and versatility of these ligands is due to the different exposition geometries of the binding units that can be explored exploiting the conformational properties of these macrocycles, the wide variety of functionalities that can be linked to their structure at different distances from the aromatic units and to their intrinsic multivalent nature. With the aim of creating new multivalent systems for protein targeting, the work reported in this thesis regards the synthesis and properties of glycocalix[n]arenes and guanidino calix[4]arenes for different purposes. Firstly, a new bolaamphiphile glycocalix[4]arene in 1,3-alternate geometry, bearing cellobiose, was synthesized for the preparation of targeted drug delivery systems based on liposomes. The formed stable mixed liposomes obtained by mixing the macrocycle with DOPC were shown to be able of exploiting the sugar units emerging from the lipid bilayer to agglutinate Concanavalin A, a lectin specific for glucose. Moreover, always thanks to the presence of the glycocalixarene in the layer, the same liposomes demonstrated through preliminary experiments to be uptaken by cancer cells overexpressing glucose receptors on their exterior surface more efficiently respect to simple DOPC liposomes lacking glucose units in their structure. Then a small library of glycocalix[n]arenes having different valency and geometry was prepared, for the creation of potentially active immunostimulants against Streptococcus pneumoniae, particularly the 19F serotype, one of the most virulent. These synthesized glycocalixarenes bearing β-N-acetylmannosamine as antigenic unit were compared with the natural polysaccharide on the binding to the specific anti-19F human polyclonal antibody, to verify their inhibition potency. Among all, the glycocalixarene based on the conformationally mobile calix[4]arene resulted the more efficient ligand, probably due its major possibility to explore the antibody surface and dispose the antigenic units in a proper arrangement for the interaction process. These results pointed out the importance of how the different multivalent presentation in space of the glycosyl units can influence the recognition phenomena. At last, NMR studies, using particularly 1H-15N HSQC experiments, were performed on selected glycocalix[6]arenes and guanidino calix[4]arenes blocked in the cone geometry, in order to better understand protein-ligand interactions. The glycosylated compounds were studied with Ralstonia solanacearum lectin, in order to better understand the nature of the carbohydrate‐lectin interactions in solution. The series of cationic calixarene was employed with three different acidic proteins: GB1, Fld and alpha synuclein. Particularly GB1 and Fld were observed to interact with all five cationic calix[4]arenes but showing different behaviours and affinities.

Síntese de potencial inibidor de acetilcolinesterase para tratamento da Doença de Alzheimer

A doença de Alzheimer (DA) é a forma mais comum de demência, representando cerca de 80% dos casos. A DA é caracterizada por um processo de declínio progressivo e irreversível das funções cognitivas e da memória, que se estende para a desorganização do comportamento. Atualmente, 46,8 milhões de pessoas em todo o mundo foram diagnosticadas com demência. Embora vários fatores tenham sido implicados na DA, sua etiologia ainda não é completamente conhecida. Do ponto de vista neuropatológico, é observado no cérebro de indivíduos com DA atrofia cortical difusa, presença de grande número de placas senis, emaranhados neurofibrilares, processo inflamatório e perda neuronal. A progressão dos sintomas está associada a mudanças estruturais nas sinapses colinérgicas em certas regiões do cérebro, que consequentemente, apresentam neurotransmissão colinérgica reduzida. Os vários eventos patológicos interligados contribuem para o avanço da doença e direcionam diversas pesquisas na busca por tratamentos multialvos com base no processo multifatorial de DA. Assim o presente trabalho descreve a síntese de derivados híbridos dual binding site de donepezila-tacrina (fármacos inibidores de acetilcolinesterase), com potencial para agir em dois alvos terapêuticos pela (i) inibição da acetilcolinesterase em ambos os sítios ativo e periférico, como demonstrado pelos estudos de modelagem molecular, e (ii) na agregação do peptídeo A? neurotóxico induzido pela acetilcolinesterase, na tentativa de interromper a progressão da doença. A estratégia sintética envolveu a condensação da 5,6-dimetóxiindanona com a unidade 4-piperidinil carbaldeído, a qual forneceu o intermediário 5,6- dimetóxindan-1-ona-4-piperidinil-metileno-1-[(4-cloroquinolin-2-il)metil], seguido de redução da dupla ligação, gerada na reação de condensação anterior, e substituição do átomo de cloro-quinolina por amino para obtenção do produto final, ou manutenção da função olefina, seguido de substituição do átomo de cloro-quinolina por azido ou amino, gerando cinco híbridos estruturalmente correlacionados. Os híbridos foram testados em ensaio de inibição de acetilcolinesterase e butirilcolinesterase pelo método de Ellman, e o híbrido insaturado, contendo a função amino-quinolina foi o mais ativo da série com IC50 na faixa de nanomolar (0,014 ?M). Futuramente, os intermediários da reação e produto final serão submetidos ao ensaio de inibição da agregação do peptídeo A? neurotóxico pelo método da tioflavina T. Neste trabalho, também são descritos os testes de predição in vitro para permeação pela barreira hematoencefálica, bem como sua absorção intestinal, pelo método PAMPA.

Impact of artifact correction methods on R-R interbeat signals to quantifying heart rate variability (HRV) according to linear and nonlinear methods.

In the analysis of heart rate variability (HRV) are used temporal series that contains the distances between successive heartbeats in order to assess autonomic regulation of the cardiovascular system. These series are obtained from the electrocardiogram (ECG) signal analysis, which can be affected by different types of artifacts leading to incorrect interpretations in the analysis of the HRV signals. Classic approach to deal with these artifacts implies the use of correction methods, some of them based on interpolation, substitution or statistical techniques. However, there are few studies that shows the accuracy and performance of these correction methods on real HRV signals. This study aims to determine the performance of some linear and non-linear correction methods on HRV signals with induced artefacts by quantification of its linear and nonlinear HRV parameters. As part of the methodology, ECG signals of rats measured using the technique of telemetry were used to generate real heart rate variability signals without any error. In these series were simulated missing points (beats) in different quantities in order to emulate a real experimental situation as accurately as possible. In order to compare recovering efficiency, deletion (DEL), linear interpolation (LI), cubic spline interpolation (CI), moving average window (MAW) and nonlinear predictive interpolation (NPI) were used as correction methods for the series with induced artifacts. The accuracy of each correction method was known through the results obtained after the measurement of the mean value of the series (AVNN), standard deviation (SDNN), root mean square error of the differences between successive heartbeats (RMSSD), Lomb\'s periodogram (LSP), Detrended Fluctuation Analysis (DFA), multiscale entropy (MSE) and symbolic dynamics (SD) on each HRV signal with and without artifacts. The results show that, at low levels of missing points the performance of all correction techniques are very similar with very close values for each HRV parameter. However, at higher levels of losses only the NPI method allows to obtain HRV parameters with low error values and low quantity of significant differences in comparison to the values calculated for the same signals without the presence of missing points.

Supercondutividade em ligas de Ta1-xZrx

No presente estudo, amostras policristalinas ricas em Ta e com estequiometrias Ta1-xZrx; x < 0.15; foram preparadas através da mistura apropriada dos elementos metálicos, os quais foram fundidos em forno a arco elétrico sobre uma placa de cobre refrigerada a água e sob atmosfera de argônio de alta pureza. Os padrões de difração de raios-X das ligas, como fundidas (as cast) e tratadas termicamente a 850 °C por 24 h, revelaram a ocorrência de uma estrutura cristalina cúbica de corpo centrada bcc, tipo W, e parâmetros de rede que aumentam suavemente com o aumento do teor de Zr nas ligas. Medidas de susceptibilidade magnética dc, conduzidas nas condições de resfriamento da amostra em campo zero (ZFC) e do resfriamento com o campo magnético aplicado (FC), indicaram que supercondutividade volumétrica é observada abaixo de ~ 5.8, 6.9, 7.0 K em amostras com x = 0.05, 0.08, e 0.10, respectivamente. Essas temperaturas críticas supercondutoras são bastante superiores àquela observada no Ta elementar ~ 4.45 K. Medidas de resistividade elétrica na presença de campos magnéticos aplicados de até 9 T confirmaram a temperatura crítica supercondutora das amostras estudadas. O campo crítico superior Hc2 e o comprimento de coerência E foram estimados a partir dos dados de magnetorresistência. Os valores estimados de Hc2 foram de ~ 0.46, 1.78, 3.85 e 3.97 T, resultando em valores de E ~ 26.0, 13.6, 9.2 e 9.1 nm para as ligas as cast com x = 0.00, 0.05, 0.08 e 0.10, respectivamente. A partir dos dados experimentais do calor específico Cp das ligas, magnitudes estimadas do salto em Cp nas vizinhanças das transições supercondutoras indicaram valores maiores que o previsto pela teoria BCS. Utilizando as equações analíticas derivadas da teoria do acoplamento forte da supercondutividade foi então proposto que o aumento da temperatura de transição supercondutora nas ligas devido a substituição parcial do Ta por Zr está intimamente relacionado ao aumento do acoplamento elétron-fônon, visto que a densidade de estados eletrônicos no nível de Fermi foi estimada ser essencialmente constante através da série Ta1-xZrx com x < 0.10.

Habilidades funcionais de autocuidado, mobilidade e função social em crianças com fissura labiopalatina e Espectro Óculo-Aurículo-Vertebral (EOAV)

As anomalias craniofaciais ocasionam comprometimentos estéticos e funcionais com grande impacto na saúde e na integração social da criança, com interferência no desenvolvimento global e social. Das anomalias craniofaciais este estudo abordou as Fissuras Labiopalatinas (FLP) e o Espectro Óculo Aurículo Vertebral (EOAV). As FLP constituem malformações resultantes de falta do fechamento completo dos tecidos que compõe o lábio e o palato. O EOAV, também conhecido como Síndrome de Goldenhar, é uma anomalia congênita de etiologia desconhecida, com manifestação genética variável e de causa bastante heterogênea. Conhecer as habilidades funcionais e o impacto destas no desenvolvimento global de crianças com EOAV e FLP pode otimizar o desenvolvimento de programas de prevenção e intervenção para promover a saúde e a integração social destes indivíduos. Este estudo foi delineado com objetivo de verificar e comparar o desempenho em habilidades funcionais quanto ao desempenho nas áreas de autocuidado, mobilidade, função social e nível de independência entre crianças com EOAV, crianças com FLP e um grupo comparativo, de crianças sem anomalias. O modelo de pesquisa foi observacional descritivo transversal com uma casuística de 39 pais/responsáveis de crianças na faixa etária entre três anos e sete anos e seis meses, de ambos os gêneros. Foram convidados para participar pais/responsáveis de crianças em tratamento no Hospital de Reabilitação de Anomalias Craniofaciais da Universidade e São Paulo (HRAC-USP) os quais foram divididos em três grupos: dois experimentais e um grupo comparativo. O instrumento para coleta dos dados das habilidades funcionais foi o Pediatric Evaluation of Disability Inventory (PEDI), em sua versão adaptada para o português. A avaliação é realizada por meio de entrevista com o cuidador, o qual deve saber informar sobre o desempenho da criança em atividades e tarefas típicas da rotina diária. Os dados foram apresentados por análise descritiva com medidas de tendência central (média aritmética), dispersão (desvio-padrão) e distribuição de frequência, nas variáveis: idades, gênero e nível socioeconômico da família e caracterização da casuística. Para as análises das pontuações bruta e normativa do questionário PEDI no que se refere às habilidades funcionais e a assistência do cuidador nas três áreas de função autocuidado, mobilidade e função social, foi utilizado o teste de variância One Way, e para o teste de normalidade foi utilizado Shapiro Wilk para variável dependente. A análise comparativa foi realizada pelo teste de Kruskal-Wallis, adotando-se o valor de significância de p< 0,05. Os resultados deste estudo na análise comparativa nas habilidades funcionais na mobilidade, houve diferença estatisticamente significante na comparação entre os grupos GC vs GEEOAV, no escore bruto, e entre os grupos GC vs GEEOAV e GC vs GEFLP, no escore normativo.Na assistência do cuidador no autocuidado, houve diferença estatisticamente significante na comparação entre os grupos GC vs GEEOAV, no escore normativo. Na assistência do cuidador na mobilidade, houve diferença estatisticamente significante na comparação entre os grupos GC vs GEEOAV nos escores bruto e normativo.Na assistência do cuidador na função social houve diferença estatisticamente significante na comparação entre os grupos GC vs GEFLP.

La narrativa en La Ilustración (1849-1857): la «Serie B» del Semanario Pintoresco Español

En los ocho años de vida de La Ilustración, la narrativa, larga y breve, fue uno de los elementos fundamentales de este periódico ilustrado. El artículo analiza los relatos que allí aparecieron y los efectos que las necesidades industriales y comerciales tuvieron en una revista que luchaba por sobrevivir económicamente. Ángel Fernández de los Ríos, propietario del Semanario Pintoresco Español y de La Ilustración, convirtió a esta última, en lo que toca a la narrativa, en una especie de serie B, en la que se entremezclaban reediciones, traducciones y colaboraciones que no habían llegado a tener el nivel suficiente para llegar a las páginas del Semanario Pintoresco Español. La abundancia de reediciones y las diversas fuentes de las que proceden hacen ver que en su selección fue más importante la imperiosa necesidad de sacar la publicación a la calle cada quince días que otros criterios. Ello también explica la abundancia de traducciones de novelas y cuentos en las páginas de La Ilustración. Traducciones y reediciones son el cuerpo principal de la narrativa publicada en La Ilustración y si tenemos que detenernos en las obras de más calidad que allí aparecen, será en este tipo de relatos, puesto que los textos narrativos originales, muy a menudo publicados sin firma de autor, resultan de muy escaso interés. Solo podemos contra con la excepción de dos relatos de José Güell y Renté (Anacaona y Quibiam) y uno de Gertrudis Gómez de Avellaneda: La baronesa de Joux. No representa, pues, La Ilustración una fuente de importancia para la narración española del medio siglo. Su posición subordinada al Semanario Pintoresco Español impidió que la publicación desarrollara una línea de narraciones de calidad. Es testimonio, sin embargo, de un proceso de industrialización de la labor periodística y literaria que estaba desarrollándose con gran celeridad si tenemos en cuenta el fracaso de El Artista y del No me olvides apenas quince años antes. A la altura del medio siglo el periodismo literario se había convertido en una industria que exigía ingentes esfuerzos de trabajo y una producción torrencial.

Preliminary interpretation of shaking-table response of a full-scale 3-storey building composed of thin reinforced concrete sandwich walls

In the last few decades, the use of cast in situ reinforced concrete sandwich panels for the construction of low- to mid-rise buildings has become more and more widespread due to several interesting properties of this construction technique, such as fast construction and high thermal and acoustic performances. Nonetheless the level of knowledge of the structural behavior of systems made of squat reinforced concrete sandwich panels is still not so consolidated, especially with reference to the seismic response, due to the lack of experimental studies. In recent years, while various experimental tests have been conducted on single panels aimed at assessing their seismic capacity, only few tests have been carried out on more complex structural systems. In this paper, the experimental results of a series of shaking-table tests performed on a full-scale 3-storey building are presented in detail. The main goal is to give to the scientific community the possibility of develop independent interpretation of these experimental results. An in-depth interpretation of the discrepancies between the analytical predictions and the experimental results is beyond the objective of this paper and is still under development. Nonetheless, preliminary interpretations indicate that both the stiffness and the strength of the building under dynamic excitation appear quite superior with respect to those expected from the results of previous pseudo-static cyclic tests conducted on simple specimens.

Shaking-table tests of flat-bottom circular silos containing grain-like material

According to Eurocode 8, the seismic design of flat-bottom circular silos containing grain-like material is based on a rough estimate of the inertial force imposed on the structure by the ensiled content during an earthquake: 80% of the mass of the content multiplied by the peak ground acceleration. A recent analytical consideration of the horizontal shear force mobilised within the ensiled material during an earthquake proposed by some of the authors has resulted in a radically reduced estimate of this load suggesting that, in practice, the effective mass of the content is significantly less than that specified. This paper describes a series of laboratory tests that featured shaking table and a silo model, which were conducted in order to obtain some experimental data to verify the proposed theoretical formulations and to compare with the established code provisions. Several tests have been performed with different heights of ensiled material – about 0.5 mm diameter Ballotini glass – and different magnitudes of grain–wall friction. The results indicate that in all cases, the effective mass is indeed lower than the Eurocode specification, suggesting that the specification is overly conservative, and that the wall–grain friction coefficient strongly affects the overturning moment at the silo base. At peak ground accelerations up to around 0.35 g, the proposed analytical formulation provides an improved estimate of the inertial force imposed on such structures by their contents.

NOx storage and reduction over copper-based catalysts. Part 2: Ce0.8M0.2Oδ supports (M = Zr, La, Ce, Pr or Nd)

5% copper catalysts with Ce0.8M0.2Oδ supports (M = Zr, La, Ce, Pr or Nd) have been studied by rapid-scan operando DRIFTS for NOx Storage and Reduction (NSR) with high frequency (30 s) CO, H2 and 50%CO + 50%H2 micropulses. In the absence of reductant pulses, below 200–250 °C NOx was stored on the catalysts as nitrite and nitro groups, and above this temperature nitrates were the main species identified. The thermal stability of the NOx species stored on the catalysts depended on the acid/basic character of the dopant (M more acidic = NOx stored less stable ⇒ Zr4+ < none < Nd3+ < Pr3+ < La3+ ⇐ M more basic = NOx stored more stable). Catalysts regeneration was more efficient with H2 than with CO, and the CO + H2 mixture presented an intermediate behavior, but with smaller differences among the series of catalyst than observed using CO alone. N2 is the main NOx reduction product upon H2 regeneration. The highest NOx removal in NSR experiments performed at 400 °C with CO + H2 pulses was achieved with the catalyst with the most basic dopant (CuO/Ce0.8La0.2Oδ) while the poorest performing catalyst was that with the most acidic dopant (CuO/Ce0.8Zr0.2Oδ). The poor performance of CuO/Ce0.8Zr0.2Oδ in NSR experiments with CO pulses was attributed to its lower oxidation capacity compared to the other catalysts.

I. Charlestown ferry bound volume, 1707-1806

This series contains sixty-nine documents related to the College's interest in the Charlestown ferry between 1707 and 1806 that were gathered together, arranged in chronological order, and pasted into a bound volume at an undetermined date. The majority of documents are leases and bonds with the ferrymen, as well as handwritten copies of Corporation petitions to the General Court regarding ferry fares and bridge development. The series also includes handwritten legal opinions composed by Levi Lincoln and Nathan Dane for the College analyzing the rights of the College to transportation-related income.

Binding papers, 1775-1928

The binding papers contain lists of volumes bound for the Harvard library in the form of lists and bills. The books are generally identified by title, volume size (octavo, quarto, folio, etc.), or both. The series includes two 18th century documents. The first document is a one-page January 22, 1775 bill to Harvard College from "Dr. And'r Barclay" for the binding and numbering of books. Books are identified by volume size. The second document is a one-page "List of books belonging to the Library which it is necessary should be new-bound" with an initial list signed by James Winthrop the Librarian on December 13, 1786, an additional list made on April 7, 1787, and subsequent notes made in May 1787. The books are indicated by title and size.

Popery a complex falsehood: or an attempt to clear and evidence, that it is so, in a lecture had at Harvard College in Cambridge, New England, on May 10th, 1769

The hand-sewn notebook contains a 30-page manuscript draft of the Dudleian lecture delivered by Samuel Mather on May 10, 1769 at Harvard College. The sermon begins with the Biblical text 2 Thess. 11:11, 12. The copy includes a small number of edits and struck-out words. The item has unattached pages and is in fragile condition. The lecture was never published.

China 1:200,000 : Sheet H-50-XXIV : Zhejiang Sheng Region (Raster Image)

This layer is a georeferenced raster image of the Soviet Army topographic sheet map covering a portion of the Zhejiang Sheng region, China (map quadrangle number: H-50-XXIV). It is from a series of Soviet Army topographic maps of China 1:200,000. The source map was published in 1979. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Pulkovo 1942 GK Zone 20N projection. Map collar information from the source map have been cropped and are not available as part of the raster image. China 1:200,000 topographic maps were prepared and printed by the Soviet Army General Headquarters, 1976-1991. China 1:200,000 maps are in Russian. Each source map in the series is printed in color. China 1:200,000 maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works and structures of humans, such as roads, railroads, paths, walls, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 40 meters and/or spot heights.

China 1:200,000 : Sheet H-50-XXX : Zhejiang Sheng Region (Raster Image)

This layer is a georeferenced raster image of the Soviet Army topographic sheet map covering a portion of the Zhejiang Sheng region, China (map quadrangle number: H-50-XXX). It is from a series of Soviet Army topographic maps of China 1:200,000. Published in 1979, the source map was compiled from maps 1:100,000 published in 1977; corrected according to source material, 1970-1975. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Pulkovo 1942 GK Zone 20N projection. Map collar information from the source map have been cropped and are not available as part of the raster image. China 1:200,000 topographic maps were prepared and printed by the Soviet Army General Headquarters, 1976-1991. China 1:200,000 maps are in Russian. Each source map in the series is printed in color. China 1:200,000 maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works and structures of humans, such as roads, railroads, paths, walls, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 40 meters and/or spot heights.

China 1:200,000 : Shaoxing Region, Zhejiang Sheng (Raster Image)

This layer is a georeferenced raster image of the Soviet Army topographic sheet map of the Shaoxing region, Zhejiang Sheng, China (map quadrangle number: H-51-XIX). It is from a series of Soviet Army topographic maps of China 1:200,000. Published in 1979, the source map was compiled from maps 1:100,000 published in 1977; corrected according to source material, 1973, 1974. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Pulkovo 1942 GK Zone 20N projection. Map collar information from the source map have been cropped and are not available as part of the raster image. China 1:200,000 topographic maps were prepared and printed by the Soviet Army General Headquarters, 1976-1991. China 1:200,000 maps are in Russian. Each source map in the series is printed in color. China 1:200,000 maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works and structures of humans, such as roads, railroads, paths, walls, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 40 meters and/or spot heights.