Enraizamento de estacas caulinares de kiwi (Actinidia chinensis Planch cv Abbott) tratadas com auxinas e boro

O trabalho teve como finalidade, estudar o efeito de várias auxinas sintéticas em formulações comerciais e do boro, sobre o enraizamento de estacas caulinares de kiwi (Actinidia chinensis Planch, cv Abbott.). As estacas utilizadas continham dois nós e duas folhas cortadas ao meio, com aproximadamente 10 cm de comprimento, onde o corte basal em bisel foi realizado logo abaixo de um nó e o apical acima do outro nó. O efeito das auxinas, sobre o enraizamento de estacas caulinares de kiwi foi verificado mediante os seguintes tratamentos, aplicados sobre as bases das estacas: T1 H(2)0); T2 (NAA 300 ppm); T3 (IBA 300 ppm); T4 (NAA 300 ppm + B); T5 (IBA 300 ppm + B); T6 (NAA 0,5%-pó) e T7 (IBA 0,5%-pó). Após o tratamento das estacas, estas foram plantadas em bandejas de enraizamento, contendo vermiculita pura e colocadas em câmara de nebulização, onde permaneceram por 120 dias, até a sua coleta. Para a avaliação do efeito de auxinas e do ácido bórico, sobre o enraizamento de estacas caulinares de kiwi, foram realizadas as seguintes observações: 1. porcentagem de estacas enraizadas; 2. análise de açúcares redutores e açúcares totais (em g/100 g de matéria seca); 3. análise de triptofano (em µg/100 mg de matéria seca). Os resultados obtidos no processo de enraizamento de estacas caulinares de kiwi (Actinidia chinensis Planch.) variedade Abbott, levou a concluir que o inverno e outono foram as melhores épocas de coleta dos ramos de auxinas para a confecção das estacas. O processo de enraizamento foi ainda incrementado com a aplicação exógena na base das estacas, sendo que o alto teor de açúcares redutores e totais beneficiou a maior porcentagem de enraizamento.

NEAR-RESONANT SCATTERING FROM NONSYMMETRIC DIMERS - APPLICATIONS TO SUBSTITUTED POLYANILINES

In this work we show that, beyond the prediction of the random dimer model [Wu and Phillips, Phys. Rev. Lett. 66, 1366 (1991)], it is possible to have near resonant scattering from nonsymmetric dimers. It is shown by direct density of states calculations as well as by a procedure similar to the random dimer model that protonated chains of alkyl-substituted polyanilines support extended electronic states at the Fermi energy when a disordered distribution of symmetric or asymmetric bipolarons is present. An extension of the random dimer model to include resonant scattering by nonsymmetric dimers is proposed.

Preparation and characterization of PAni-PMMA dispersions

Blends of polyaniline (PAni) and poly(methyl methacrylate) (PMMA) have been produced using core-shell particle synthesis, which is advantageous because it allows changing surface-related properties of PMMA with relatively small amounts of PAW and without the use of organic solvents. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements indicated that the deposition of pollyaniline seems to alter the regular shape of the primary acrylic latex particles. The coverage of PMMA particles by PAW was confirmed by FTIR measurements, where distinct data were obtained from the transmission and diffuse reflectance modes, since the latter is surface sensitive. The zeta potential, which is also a surface-related property, increased with the contents of PAW, as the shells probably became protonated with PAW in the emeraldine salt form. Coverage with PAW did not affect the thermal bulk properties of the PMMA shells.

Nanoscale processing of polyaniline and phthalocyanines for sensing applications

Nanostructured polyaniline-modified electrodes were fabricated via the electrostatic layer-by-layer (LbL) technique where polyaniline (PANI) was assembled with one of three tetrasulfonated metallic phthalocyanines, viz. iron (FeTsPc), nickel (NiTsPc) and copper (CuTsPc). The multilayer formation was monitored via UV-vis spectroscopy by measuring the increase in the 800 run absorption band due to PANI. Infrared spectroscopy in the transmission mode suggested specific interactions between PANI and the phthalocyanines, such as those between SO3- groups from the phthalocyanines and the protonated NH group from PANI. The films were employed to detect dopamine (DA) using cyclic voltammetry. In the presence of dopamine the PANI-based LbL films showed additional redox peaks at ca. 230 and 190 mV the oxidation peak increased linearly with the concentration of DA in the electrolytic solution. Films comprising PANI/FeTsPc were able to distinguish between DA and ascorbic acid (AA), which acts as a natural interferent in biological fluids. (c) 2005 Elsevier B.V. All rights reserved.

Studies of the voltammetric behavior and determination of diazo reactive dyes at mercury electrode

The electrochemical reduction of two reactive dyes: Procion Red HE-3B 9 (RR120) and Procion Green HE-4BD (RG19) was investigated using cyclic voltammetry, differential pulse and DC, polarography, chronoamperometry and controlled potential electrolysis at mercury electrodes. The bis-azo groups of the RR120 dye are reduced together in one single step of four electrons, the bis-azo groups of the RG19 dye are reduced in two steps owing to the difference in the electron densities promoted by the different substituents in the benzene rings adjacent to the azo groups. The bis-monochlorotriazine reactive groups in both dyes are reduced only in acidic medium in their protonated form, leading to the reduction of the triazine groups. The reduction mechanism of both reactive dyes is discussed. Both dyes can be quantified in aqueous medium by differential pulse polarography in the concentration range of 1 x 10(-7) mol L-1 to 1 x 10(-5) mol L-1 by monitoring the reduction of the chromophore group or the reactive group.

Determination of the vinylsulphone azo dye, remazol brilliant orange 3R, by cathodic stripping voltammetry

Remazol brilliant orange 3R shows only a voltammetric peak for the reduction of the azo group. No peak was observed for the reduction of the sulfatoethylsulfone or vinylsulfone reactive groups. The reduction of a pre-protonated ate group involving a two-electron process, gives a hydrate derivative in acidic solution. In alkaline solution the reduction process occurs at more negative potential with the formation of an unstable hydrate compound which decomposes via HN-NH bond cleavage and loss of a sulfate group. Optimum conditions are given for the cathodic stripping voltammetric determination of dir: dye in aqueous solution. The optimum accumulation potential and time were 0 V and up to 60 s, respectively. Linear calibration graphs were obtained from 30 to 300 ng ml(-1) in pH 4 and 6.2 to 62 ng ml(-1) in pH 10. The limit of determination obtained was 1.5 ng ml(-1) (pH 10). The coefficient of variation was 2.6% (n = 7) at 62 ng ml(-1) of the reactive dye. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Validation of an immunoassay method for the determination of traces of carbaryl in vegetable and fruit extracts by liquid chromatography with photodiode array and mass spectrometric detection

A competitive enzyme-linked immunosorbent assay (ELISA) method for carbaryl quantitation in crop extracts was validated by liquid chromatography (LC) with diode array detection (DAD). For this purpose, six crops (banana, carrot, green bean, orange, peach and potato) were chosen for recovery and reproducibility studies. The general sample preparation included extraction with methanol followed by liquid-liquid partitioning and clean-up on Celite-charcoal adsorbent column of the vegetable extracts. ELISA samples consisted of a diluted LC extract in assay phosphate buffer (pH 7.5). The potential effect of methanol in these samples was evaluated. It was observed that a maximum content of 10% methanol present in the assay buffer could be tolerated without expressive losses in the ELISA performance. Under these conditions, a IC50 similar to 1.48 mu g l(-1) was obtained. A minimum matrix effect with a 1:50 dilution of the methanolic extracts in assay buffer was noticed, except for green bean samples that inhibited completely the assay. For the vegetable extracts, the ELISA sensitivities varied from 3.9 to 5.7 mu g l(-1), and good recoveries (82-96%) with R.S.D.s ranging from 5.7 to 12.1% were found. An excellent correlation between the LC-DAD and ELISA techniques was obtained. The confirmation of the carbaryl in less concentrated samples was achieved by LC-mass spectrometry interfaced with atmospheric pressure chemical ionisation. The [M + H](+)= 202 and [M + H-57](+)=145 ions, equivalent to the protonated molecular and l-naphthol ions, respectively, were used to carbaryl identification in these samples. (C) 1998 Elsevier B.V. B.V. All rights reserved.

Determination of aldicarb, aldicarb sulfoxide and aldicarb sulfone in some fruits and vegetables using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

An analytical method for the determination of aldicarb, and its two major metabolites, aldicarb sulfoxide and aldicarb sulfone in fruits and vegetables is described. Briefly the method consisted of the use of a methanolic extraction, liquid-liquid extraction followed by solid-phase extraction clean-up. Afterwards, the final extract is analyzed by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS). The specific fragment ion corresponding to [M-74](+) and the protonated molecular [M+K](+) ion were used for the unequivocal determination of aldicarb and its two major metabolites. The analytical performance of the proposed method and the results achieved were compared with those obtained using the common analytical method involving LC with post-column fluorescence detection (FL). The limits of detection varied between 0.2 and 1.3 ng but under LC-FL were slightly lower than when using LC-APCI-MS. However both methods permitted one to achieve the desired sensitivity for analyzing aldicarb and its metabolites in vegetables. The method developed in this work was applied to the trace determination of aldicarb and its metabolites in crop and orange extracts. (C) 2000 Elsevier B.V. B.V. All rights reserved.

Effects of auxins and boron on rooting of kiwi stem cuttings (Actinidia chinensis Pl cv Matua)

This work studies the effects of some synthetical auxins and boron in the rooting of stem cuttings of kiwi (Actinidia chinensis Planch cv Matua). The stems used had two nodes and two leaves cut in half. The auxin effect was observed through seven different treatments: T1 (H2O); T2 (NAA 300 ppm); T3 (IBA 300 ppm); T4 (NAA 300 ppm + B); T5 (IBA 300 ppm + B); T6 (NAA 0,5%-talc) and T7 (IBA 0,5%-talc), applied to the bases of stem cuttings. After these treatments, the cuttings were placed in suitable rooting dishes, with pure vermiculite in misty nebulization chamber for 120 days until collection day. The evaluation of auxin and boric acid effects were made based on the following observations: 1. The percentage of rooted stem cuttings; 2. reducing sugar and total sugar analyses; and 3. tryptophan analyses. The effects of such treatments were observed in the four seasons. The results showed that winter is best for rooting. Application of IBA talc 0,5% to the cuttings bases increased rooting.

Action of auxins, boron and harvest season on the rooting of kiwi fruit stem cuttings (Actinidia chinensis Pl cv Monty)

Action of auxins on the rooting of stem cuttings of kiwi (Actinidia chinensis P. cv Monty). This work studies the effects of some synthetic auxins and B in the rooting of kiwi (Actinidia chinensis Planch cv Monty) stem cuttings. The treatments used were as follows: T1 (H2O); T2 (NAA 300 ppm); T3 (IBA 300 ppm); T4 (NAA 300 ppm + B); T5 (IBA 300 ppm + B); T6 (NAA 0,5%-talc) and T7 (IBA 0,5%-talc), applied to the bases of the cuttings. These were then placed in rooting dishes with pure vermiculite in a misty nebulization chamber until collection day (120 days). The evaluation of auxin and boric acid effects on kiwi stem cuttings were made based on the following observations: 1. The percentage of rooted stem cuttings; 2. reducing sugars and total sugar analyses (in g/100 g of dry matter); and 3. tryptophan analyses (in mu g/100 mg of dry matter). The results show that summer is the best season for rooting Actinidia chinensis Planch cv Monty stem cuttings. The use of IBA talc 0,5% on the bases of the cuttings shamed positive results too.

Thermo-Reversible Sol-Gel Transition of Surface Modified Titanium Poly Oxo Building Blocks

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Magnetic field dependent magnetization of a conducting plasticized poly(aniline) film

We report magnetic data of free standing films of poly( aniline) (PANI) protonated with a plasticizing di-ester of succinic acid. The data have been obtained using the electron spin resonance (ESR) technique at two different frequencies, X-band (9.4 GHz) and Q-band ( 34 GHz), on one hand, and by magnetization measurements in broad ranges of temperatures and magnetic fields on the other hand. All the data can be explained assuming a transition as a function of temperature from delocalized magnetic moments in the valence band to localized positive polarons in several antiferromagnetically correlated bands. By increasing the magnetic field, the magnetic properties are affected in several ways. An intra-band admixture of states occurs; it contributes to increase the spins' localization and finally promotes an antiferromagnetic-metamagnetic transition.

Thermo-reversible sol-gel transition of TiO2 nanoparticles with surface modified by p-toluene sulfonic acid

In this paper an unprecedent thermo-reversible sol-gel transition for titania nanoparticles dispersed in a solution of p-toluene sulfonic acid (PTSH) in isopropanol is reported. The sol formed by the thermo-hydrolysis at 60 degrees C of titanium tetraisopropoxide (Ti((OPr)-Pr-i)(4)) reversibly changes into a turbid gel upon cooling to room temperature. Turbidimetric measurements performed for samples containing different nominal acidity ratios (A = [PTSH]/[Ti]) have evidenced that the gel transformation temperature increases from 20 to 35 degrees C as the [PTSH]/[Ti] ratio increases from 0.2 to 2.0. SAXS results indicate that the thermo-reversible gelation is associated to a reversible aggregation of a monodisperse set of titania nanoparticles with average gyration radius of approximate to 2 nm. From the different PTSH species evidenced by Raman spectroscopy and TG/DTA of dried gels we proposed that the then-no-reversible gelation in this systems is induced by the formation of a supramolecular network, in which the protonated surface of nanoparticles is interconnected through cooperative hydrogen bonds between -SO3 groups of p-toluene sulfonic acid. (C) 2009 Elsevier Ltd. All rights reserved.

Implicações nutricionais no tratamento e recuperação de pacientes adultos com diarréia crônica.

The nutritional assessment by 24 hour-dietary recall, anthropometry and blood-components measurements was undertaken in 23 adult patients, 17 males and 6 females suffering of chronic diarrhea from pancreatitis (30%), inflammatory bowel disease (22%), short intestine syndrome (9%) and unknown diarrhea (35%). The nutritional assessment was done at the entry and repeated at the discharge of the hospitalization that averaged 35 days, during which the patients received specific medical treatment along with obstipating diets. The hospitalization resulted in overall improvement of the patients either clinically by reducing their defecation rate or nutritionally by increasing their protein-energy intake and the values of anthropometry and blood components (albumin, free-tryptophan and lymphocytes). When the patients where divided into two groups based on their fecal-fat output one could note the better nutritional response of the group showing steatorrhea than the non-steatorrhea group, with the serum albumin and the arm-muscle circumference being discriminatory between groups. However even in the better recovered patients the indicative values of a satisfactory nutritional status were not accomplished. Thus, these data suggest that besides the overall nutritional improvement seen in the studied chronic diarrhea patients the full-nutrition recovering would demand either or both a longer hospitalization and/or an early-aggressive nutritional support.

Plasma levels of transthyretin and retinol-binding protein in child-a cirrhotic patients in relation to protein-calorie status and plasma amino acids, zinc, vitamin a and plasma thyroid hormones

Transthyretin and retinal-binding protein are sensitive markers of acute protein-calorie malnutrition both for early diagnosis and dietary evaluation. A preliminary study showed that retinal-binding protein is the most sensitive marker of protein-calorie malnutrition in cirrhotic patients, even those with the mild form of the disease (Child A). However, in addition to being affected by protein-calorie malnutrition, the levels of these short half-life-liver-produced proteins are also influenced by other factors of a nutritional (zinc, tryptophan, vitamin A, etc) and non-nutritional (sex, aging, hormones, renal and liver functions and inflammatory activity) nature. These interactions were investigated in 11 adult male patients (49.9 ± 9.2 years of age) with alcoholic cirrhosis (Child-Pugh grade A) and with normal renal function. Both transthyretin and retinol binding protein were reduced below normal levels in 55% of the patients, in close agreement with their plasma levels of retinal. In 67% of the patients (4/6), the reduced levels of transthyretin and retinal-binding protein were caused by altered liver function and in 50% (3/6) they were caused by protein-calorie malnutrition. Thus, the present data, taken as a whole, indicate that reduced transthyretin and retinal-binding protein levels in mild cirrhosis of the liver are mainly due to liver failure and/or vitamin A status rather than representing an isolated protein-calorie malnutrition indicator.