Linfangiectasia renal: achado incidental em tomografia computadorizada multicorte e revisão da literatura

Linfangiectasia renal é uma condição rara, caracterizada por coleções parapiélicas e perirrenais, que pode progredir de assintomática para insuficiência renal crônica. É apresentado um caso de achado incidental em tomografia computadorizada de linfangiectasia renal bilateral em paciente assintomático, com descrição dos principais achados à luz dos métodos de imagem e ampla revisão da literatura.

As "Disquisitiones" do naturalista Arruda da Câmara (1752-1811) e as relações entre a Química e a Fisiologia no final do Século das Luzes

This work is intended to rescue the field of validity of the "Disquisitiones" by the naturalist Arruda da Câmara placing them in the scientific and historical context of the end of the "Century of Light". Thus, a tentative is made here to reconstruct the debate established among the several theories that served as background of the relationships between Chemistry and Physiology of that time. In the present work is presented by the first time an integral translation of the "Disquisitiones" and a biographical resume of the naturalist in the historical context of his epoch in Northeast Brazil, especially in Pernambuco.

Optical characterization of sol-gel glasses derived from Eu3+ complex-forming precursors

Fabrication of new optical devices based upon the incorporation of rare earth ions via sol-gel methods depends on elimination of dopant ion clusters and residual hydroxyl groups from the final material. The optical absorption and/or luminescence properties of luminescent rare earth ions are influenced by the local bonding environment and the distribution of the rare-earth dopants in the matrix. Typically, dopants are incorporated into gel via dissolution of soluble species into the initial precursor sol. In this work, Eu3+ is used as optical probe, to assess changes in the local environment. Results of emission, excitation, fluorescence line narrowing and lifetimes studies of Eu3+-doped gels derived from Si(OCH3)4 and fluorinated/chelate Eu3+ precursors are presented. The precursors used in the sol-gel synthesis were: tris (6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) Eu(III), Eu (III) trifluoromethanesulfonate, Eu(III) acetylacetonate hydrate, Eu (III) trifluoroacetate trihidrate, tris (2,2,6,6-tetramethyl-3,5- heptanedionate) Eu(III) and Eu(NO3)3.6H2O. The results were interpreted in terms of the evolution of the Eu3+ fluorescence in systems varying from solution to the gels densified to 800ºC. The lifetimes studies indicate that the fluorinated precursors are effective at reducing the water content in densified gels.

Connectivity in sol-gel silica glasses

In this work it is carried out a review on structural parameters related to the evaluation of pore connectivity of nanostructures. The work describes parameters and methods of evaluation of geometric parameters. The concepts of connectivity are applied to silica gels and glasses obtained from sol-gel process. The study of pores connectivity was carried out using a combination of geometric modeling and experimental evaluation of specific surface area and pore volume. The permeability of the pore structure is evaluated and a permeability geometric factor, Pg, is proposed.

Síntese de membranas cerâmicas via método sol-gel utilizando TEOS e N,N-dimetilformamida

In this work we obtained microporous and mesoporous silica membranes by sol-gel processing. Tetraethylortosilicate (TEOS) was used as precursor. Nitric acid was used as catalyst. In order to study the affect of N,N-dimethylformamide (NDF) as drying additive, we used a molar ratio TEOS/NDF of 1/3. The performance of N,N-dimethylformamide was evaluated through monolithicity measurements. The structural evolutions occurring during the sol-gel transition and in the interconnected network of the membranes during thermal treatment were monitored by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyses and nitrogen sorption. We noted that in the presence of N,N-dimethylformamide, polymerization goes through a temporary stabilization of oligomers. The Si-O(H) bonds are stronger and belong to a more cross-linked structure for the N,N-dimethylformamide containing sol. The membranes obtained in the presence of N,N-dimethylformamide have larger surface area and its pore structure is in the range of mesoporous. The membranes obtained without additive have pore structure in the range of microporous.

Uso de métodos analíticos convencionados no estudo da autenticidade do óleo de copaíba

The acidity and ester index are suggested, as simple and cheap methods, adequate to be employed in the study of the authenticity of copaíba oil by small drugstores and export firms. The acidity index permits both the detection and the evaluation of the content of adulteration of copaíba oil. The ester index permits to know if the adulterant either contain ester compounds,as the case of fatty oils, or contain only non saponifiable compounds as is the case of ethyl alchool or mineral oil. The results of the aplication of the methods to eight commercial samples, of copaiba oil, where three samples were adultered, are coherent with those obtained by more sophisticated instrumental methods.

Fármacos no combate à tuberculose: passado, presente e futuro

Approximately every minute, somewhere in the world four people die from tuberculosis (TB), an infection of Mycobacterium tuberculosis with about 3 million deaths per year. In spite of these problems, unfortunaly, it is about 40 years that a novel drug was last introduced on the market. Due to the rapid spread of multi-drug resistant TB strains, resistant against all major anti-tuberculosis drugs, and the recent resurgence of the incidence of tuberculosis in association with the human immunodeficiency virus (HIV) infection and AIDS, we need urgently the development of new drugs to fight tuberculosis. This is covered in the present article.

Um fotômetro multi-led microcontrolado, portátil e de baixo custo

A microcontrolled, portable and inexpensive photometer is described. It uses six light-emitting diodes (LEDs) as radiation sources and a phototransistor as detector, as well as a microcontroller (PIC - Programmable Controller of Interruption). This device provided total autonomy to the proposed photometer, which was successfully applied to determination of Fe2+ in ferrous syrups and of seven clinical biochemical parameters. As the components are cheap (~U$30.00) and easy to find, the proposed photometer is an economical alternative for routine chemical analyses in small laboratories, for research and teaching. Being portable and microcontrolled, it allows doing field chemical analyses.

Caracterização química de glucanas fúngicas e suas aplicações biotecnológicas

This article gives an overview of exopolysaccharides produced by fungi. The structural characterization of beta-D-(1->3) and beta-D-(1->3, 1->6)- glucans is discussed focusing on different chemical and physical procedures. The industrial applications are also considered mainly from the point of view of human health.

Aspectos toxicológicos e químicos da Anatoxina-a e seus análogos

Anatoxin-a and its analogues are azabicyclic alkaloids that represent one of the most powerful nicotinic agonists known for the nicotinic acetylcholine receptor (nAChR). Because of this potent mechanism of action, anatoxin-a and its derivatives represent a target for the discovery of novel drugs. Their syntheses are useful for environmental monitoring and also for pharmacokinetic/pharmacodynamic and toxicological studies. Some strategies for the synthesis of anatoxin-a and analogous compounds are described herein, covering the period from 1996 to the present date. In this review, emphasis is given to the chemical and toxicological aspects of some variants of anatoxin-a, including homoanatoxin-a and anatoxin-a(s).