Heterotaxy syndrome: a case report

The present report describes the findings at chest computed tomography angiography of a 28-year-old female patient with heterotaxy syndrome. This syndrome consists of a variety of anomalies of position and morphology of thoracoabdominal organs which do not follow the situs solitus or situs inversus arrangement. Imaging studies play a fundamental role in the individualization of the approach to the patient.

Heterotaxy syndrome: a case report

Heterotaxy syndrome is defined as an abnormal arrangement of some organs and vessels in association with dysmorphism. The authors describe the case of a patient with heterotaxy syndrome with poliesplenia incidentally diagnosed during imaging evaluation (computed tomography and small bowel barium study) of unrelated pathological condition.

Intercalação Eletroquímica de Cátions Hexilamínio na Matriz Lamelar 1T-TiS2

The electrochemical synthesis of a ternary compound obtained by the intercalation of hydrated hexilaminium cations into the layered compound 1T-TiS2 is reported. Two different compounds were detected by cyclovoltammetry and studied by X-ray diffractometry. Models showing the steric arrangement of the hydrated hexilaminium cations into the Van der Waals gaps were proposed.

Estudio estructural del MoO3 y sus planos cristalinos

In the present work we present geometric models of the most studied MoO3 surfaces, which were obtained using the DTMM 2.0 Molecular Modeller software. MoO3 has an orthorhombic layered structure, with each layer comprised of two interleaved planes of MoO6 octahedral. These layers are parallel to the (010) crystal plane and only oxygen ions are exposed on their surfaces. This situation results in weak van der Waals bonding between layers and in a relatively inert surface. In our approach to surface geometric structure we consider "ideal" crystal surface, in which the bulk atomic arrangement is maintained. These surfaces were generated by imaginary cleavage along appropriate planes in the bulk crystal structure.

Preparação de nanocompósitos através do encapsulamento de polímeros condutores em 2H-MoS2 e 1T-TiS2

Nanocomposites obtained by the encapsulation of conducting polymers such as polyaniline and polydiphenylamine in 2H-MoS2 and 1T-TiS2 are synthesized and characterized by X-ray diffraction and infrared spectrophotometry. The synthesis consists in intercalating the layered compound with n-butyllithium and subsequent exfoliation in water and organic solvents. The nanocomposites are obtained by the adsorption of the polymers into the single-layers sulfides and posterior restacking. The X-ray diffraction measurements showed that the organic conducting polymers are encapsulated in mono and bilayers arrangement in a well-ordered fashion to produce single phase compounds.

Cristais Líquidos Ferroelétricos - CLF. Uma abordagem sintética

Synthetic methods used for the synthesis of the Ferroelectric Liquid Crystals (FLCs) will be considered with emphasis on the chiral synthesis methodologies and mesomorphic electrooptical properties.

Obtenção e caracterização de blendas colágeno-quitosana

Biodegradable polymer blends were obtained using collagen and chitosan. Membranes of collagen and chitosan in different proportions (3:1, 1:1 and 1:3) were prepared by mixing their acetate solutions (pH 3.5) at room temperature. The blends were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier Transform infrared (FTIR) spectroscopy, specific viscosity, water absorption and stress-strain assays. The results showed that chitosan did not interfere in the structural arrangement of the collagen triple helix and the properties of the blends can be controlled by varing the proportion of the collagen and the chitosan.

Intercalação e funcionalização da brucita com ácidos carboxílicos

Brucite (Mg(OH)2) is a structural model of several natural layered minerals as well as of synthetic layered double hydroxides (LDH). Exchange reaction studies of these compounds are well documented in the literature but surface chemical modifications, especially for brucite, are quite rare. We report the behaviour of brucite in reaction with succinic and benzoic acid in different solvents and temperatures. The compounds were analysed through X-ray diffraction (XRD) and infrared spectroscopy (FTIR). The surfaces of brucite crystals were grafted producing expansions, attributed to the arrangement of the grafted species between the layers.

Determinação experimental dos raios cristalográficos dos íons sódio e cloreto

This experiment, where very common materials and equipments are used, conducts to good and interesting results related to the ionic radii of sodium and chloride ions. It also offers an excellent opportunity to discuss the crystalline arrangement of solids and to apply simple mathematical tools for calculations. Other important concepts such as density, solubility and saturated solution are also used. The simplicity of the experiment creates an excellent opportunity for reasoning with the students about the technique.

Desenvolvimento de sistemas líquido-cristalinos empregando silicone fluido de co-polímero glicol e poliéter funcional siloxano

For the construction of the phase diagrams, the method of the aqueous titration was used. There were prepared 5 ternary diagrams, varying the surfactant and the oil phase. The liquid-crystalline phases were identified by polarized light microscopy. The formulations prepared with silicon glycol copolymer, polyether functional siloxane (PFS) and water (S1) and with diisopropyl adipate, PFS and water (S4) presented liquid-crystalline phases with lamellar arrangement. Moreover, after 15 days in hot oven (37 ºC), the formulations presented hexagonal arrangement, evidencing the influence of the temperature in the organization of the system.

Peptídeos cíclicos de biomassa vegetal: características, diversidade, biossíntese e atividades biológicas

Natural peptides are outstanding as the most promising macromolecules in the search for new drugs, especially those of cyclic nature. The higher plants revealed a very peculiar composition of their cyclic peptides, which distinguish themselves by a "head-to-tail" cyclization. It is possible to define two groups of cyclic peptides from plant biomass. Those called in this review as Eucyclopeptides formed by 2-12 amino acid, and Cyclotides considered as circular polypeptides, composed of 29-37 amino acid that retain three disulfides bridges in an arrangement known as cyclic cystine knot. Searching for plant peptides should form into a subject for scientific research in the forefront of great importance for bioprospecting natural products macromolecular.

Organização supramolecular da ftalocianina de cobalto(II) e seu efeito na oxidação do aminoácido cisteína

The interest in the chemistry of cobalt (II) tetrasulfonated phthalocyanine (PcTsCo) comes mainly from its macrocycle-ligand structure combined with their special chemical characteristics, such as high solubility, well-defined redox reactions and remarkable optical absorption in the visible region. In this work, we use layer-by-layer technique in order to assemble CoTsPc and poly(allylaminehydrochloride) (PAH) in hybrid supramolecular system. The electronic spectroscopy and cyclic voltammetry techniques were utilized to study PAH/CoTsPc multilayers growth and the cysteine catalytic oxidation. PAH/CoTsPc showed high electrochemical stability and worthwhile to mention is the remarkable influence of supramolecular arrangement on the final redox properties of the system.

Construção de espectrômetro de emissão atômica com atomização eletrotérmica em filamento de tungstênio (WCAES)

It is here discussed the development of a low cost analytical instrument with capacity for metals determination using atomic emission measurements in an electrothermal atomization system with a tungsten coil atomizer. The main goal was to show a new frontier for using this atomizer and to demonstrate that the simple instrumental arrangement here proposed has potential for portability and for solving analytical tasks related to metals determination. Atomic emission of calcium was selected for the adjustment of instrumental parameters and to evaluate the main characteristics of the lab-built instrument. Cobalt was determined in medicines and one alloy to demonstrate its feasibility.

TRIAGEM METABÓLICA POR PKS E NRPS EM ACTINOBACTÉRIAS ENDOFÍTICAS DE Citrus reticulata

Polyketides and non-ribosomal peptides are natural products widely found in bacteria, fungi and plants. The biological activities associated with these metabolites have attracted special attention in biopharmaceutical studies. Polyketide synthases act similarly to fatty acids synthetases and the whole multi-enzymatic set coordinating precursor and extending unit selection and reduction levels during chain growth. Acting in a similarly orchestrated model, non-ribosomal peptide synthetases biosynthesize NRPs. PKSs-I and NRPSs enzymatic modules and domains are collinearly organized with the parent gene sequence. This arrangement allows the use of degenerated PCR primers to amplify targeted regions in the genes corresponding to specific enzymatic domains such as ketosynthases and acyltransferases in PKSs and adenilation domains in NRPSs. Careful analysis of these short regions allows the classifying of a set of organisms according to their potential to biosynthesize PKs and NRPs. In this work, the biosynthetic potential of a set of 13 endophytic actinobacteria from Citrus reticulata for producing PKs and NRP metabolites was evaluated. The biosynthetic profile was compared to antimicrobial activity. Based on the inhibition promoted, 4 strains were considered for cluster analysis. A PKS/NRPS phylogeny was generated in order to classify some of the representative sequences throughout comparison with homologous genes. Using this approach, a molecular fingerprint was generated to help guide future studies on the most promising strains.

REAÇÃO DE CONDENSAÇÃO DO GLICEROL COM COMPOSTOS CARBONÍLICOS. SÍNTESE, CARACTERIZAÇÃO E APLICAÇÃO EM CRISTAIS LÍQUIDOS

Condensation reactions of glycerol with aldehydes and ketones were performed under thermal heating and microwave irradiation regimes. Homogeneous and heterogeneous catalysts were tested in both conditions. A silica sulfated (SiO2-SO3H) heterogeneous catalyst demonstrated the best performance relative to a selectivity of >95% in favor of 5-membered ketals. For acetals, preference in favor of 5-membered or 6-membered functional groups depends on the nature of the catalyst. Homogenous catalysts favor the more stable 6-membered acetals, whereas heterogeneous catalysts favor the less stable 5-membered acetals. However, the isomer ratios in the acetalization reaction are too low, and hence the reaction cannot be used in a synthetic plan for functional materials. Ketalization processes mediated by SiO2-SO3H show a high selectivity in favor of a 5-membered ring (1,3-dioxolane). The scope of condensation was tested with different ketones. A mechanism for heterogeneous catalysis related to the selectivity in the cyclization process is presented herein. Solketal, a commercial product, was also obtained by a condensation reaction of glycerol and propanone, and showed a high selectivity in favor of 1,3-dioxolane. It was transformed to potential allylic and chiral intermediates. A mesogenic core was connected to the organic framework of glycerol to produce a monomer liquid crystal material with a stable smectic-C mesophase.