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Search Results: 1 - 10 of 387084 matches for " Pedro C. de;Castro "
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Aplica??o de quitosana como suporte para a imobiliza??o de enzimas de interesse industrial
Mendes, Adriano A.;Oliveira, Pedro C. de;Castro, Heizir F. de;Giordano, Raquel de L. C.;
Química Nova , 2011, DOI: 10.1590/S0100-40422011000500019
Abstract: chitosan, poly[β-(1-4)-linked-2-amino-2-deoxy-d-glucose], is the n-deacetylated product of chitin which is a major component of arthropod and crustacean shells such as lobsters, crabs, shrimps, and cuttlefishes. in addition, chitosan has many significant biological and chemical properties such as biodegradability, biocompatibility and bioactivity as well as polycationic properties. thus, it has been widely used in many industrial and biomedical applications including wastewater treatment, chromatographic support, carriers for controlled drug delivery and enzyme immobilization. this review is an insight into the exploitation of utilization of chitosan based-supports in different geometrical configurations on the immobilization of enzymes by different protocols for further application in biotransformation reactions.
Chitosan/siloxane hybrid polymer: synthesis, characterization and performance as a support for immobilizing enzyme
Silva, Grazielle S.;Oliveira, Pedro C.;Giordani, Domingos S.;Castro, Heizir F. de;
Journal of the Brazilian Chemical Society , 2011, DOI: 10.1590/S0103-50532011000800003
Abstract: a hybrid polymer derived from siloxane and chitosan was obtained by sol-gel technique using tetraethoxysilane (teos) as a precursor. the hybrid support was chemically modified with epichlorohydrin and used to immobilize lipase from burkholderia cepacia. the hybrid sio2-chitosan formed new macromolecular structure in which the inorganic particles are dispersed at the nanometer scale in the organic host matrix and bounding through covalent bonds. a comparative study between free and immobilized lipase was provided in terms of ph, temperature, kinetic parameters and thermal stability. the ph for maximum hydrolysis activity shifted from 7.0 for the soluble lipase to 6.1 and the optimum temperature remained at 50 oc after immobilization. the patterns of heat stability indicated that the immobilization process provided the stabilization of the enzyme and the epoxy sio2-chitosan derivative was almost 30-fold more stable than soluble lipase at 60 oc.
Carcinoma Sarcomatoide de la glándula tiroides: a propósito de un caso
ROBERTO C. CASTRO,PEDRO GONZáLEZ,CARMEN FUENTES,GEORGE DE SANTOLO
Revista Venezolana de Oncología , 2005,
Abstract: El carcinoma sarcomatoide de la glándula tiroides es un tumor raro, de curso rápidamente fatal y que no responde en forma favorable a ningún tratamiento conocido. Se presenta el caso de una paciente femenina de 64 a os de edad quien consultó por disnea, disfagia y disfonía progresiva, con aumento de volumen en cuello de 4 meses de evolución posterior a tiroidectomía total por tumor tiroideo cuya biopsia reportó: leiomioma de tiroides. La revisión de las láminas histológicas del espécimen quirúrgico reportó carcinoma sarcomatoide. Se realizó radiología y tomografía de cuello y tórax, fibrobroncoscopia, gammagrafía tiroidea, endoscopia digestiva superior, ecografía abdominal y biopsia por trucut. Después de considerar al tumor como irresecable se inició tratamiento con radioterapia, sin obtener una respuesta favorable. La paciente falleció a los 38 días posterior a su ingreso. Sarcomatoid carcinoma of the thyroid gland is a rare tumor, with a rapidly fatal course, that does not respond favorably to any known treatment. We present the case of a 64 year old female patient with a 4 month history of dyspnea, dysphagia, and progressive dysphonia, with a neck mass posterior a total thyroidectomy. She had a past history of total thyroidectomy for a thyroid tumor reported as a leiomyoma four months before admission. The histologic slides from the thyroidectomy specimen were reviewed at our institution and findings were consistent with sarcomatoid carcinoma. Bronchoscopy, abdominal ultrasound, computed tomography and tru-cut core biopsy of the neck mass were performed. The patient was considered inoperable and external radiotherapy is initiated without favorable response. Patient dies 38 days after admission.
Immobilization of a Commercial Lipase from Penicillium camembertii (Lipase G) by Different Strategies
Adriano A. Mendes,Larissa Freitas,Ana Karine F. de Carvalho,Pedro C. de Oliveira,Heizir F. de Castro
Enzyme Research , 2011, DOI: 10.4061/2011/967239
Abstract: The objective of this work was to select the most suitable procedure to immobilize lipase from Penicillium camembertii (Lipase G). Different techniques and supports were evaluated, including physical adsorption on hydrophobic supports octyl-agarose, poly(hydroxybutyrate) and Amberlite resin XAD-4; ionic adsorption on the anionic exchange resin MANAE-agarose and covalent attachment on glyoxyl-agarose, MANAE-agarose cross-linked with glutaraldehyde, MANAE-agarose-glutaraldehyde, and epoxy-silica-polyvinyl alcohol composite. Among the tested protocols, the highest hydrolytic activity (128.2 ± 8.10?IU·g?1 of support) was achieved when the lipase was immobilized on epoxy-SiO2-PVA using hexane as coupling medium. Lipase immobilized by ionic adsorption on MANAE-agarose also gave satisfactory result, attaining 55.6 ± 2.60?IU·g?1 of support. In this procedure, the maximum loading of immobilized enzyme was 9.3?mg·g?1 of gel, and the highest activity (68.8 ± 2.70?IU·g?1 of support) was obtained when 20?mg of protein·g?1 was offered. Immobilization carried out in aqueous medium by physical adsorption on hydrophobic supports and covalent attachment on MANAE-agarose-glutaraldehyde and glyoxyl-agarose was shown to be unfeasible for Lipase G. Thermal stability tests revealed that the immobilized derivative on epoxy-SiO2-PVA composite using hexane as coupling medium had a slight higher thermal stability than the free lipase. 1. Introduction Lipases (triacylglycerol acyl hydrolases EC 3.1.1.3) are hydrolases that act on carboxylic ester bonds. The natural physiologic role of lipases is the hydrolysis of triglycerides into fatty acids and glycerol, but they can also catalyze esterifications and interesterifications in nonaqueous media [1–5]. A peculiarity mechanism action of lipases is the interfacial activation. Most lipases have a α-helical oligopeptide structure covering their active site (lid or flap) and making them inaccessible to substrates. In the absence of a hydrophobic interface, the active site is secluded from the reaction medium, and the enzyme is in the so-called “closed conformation.” However, in the presence of a hydrophobic interface (a drop of oil), the lipase changes its conformation and exposes the catalytic site to the hydrophobic phase, yielding the “open conformation” [6–9]. The limitations of the industrial use of lipases have been mainly due to their high cost, which may be overcome by immobilization techniques on solid supports. Immobilization facilitates the separation of products and provides more flexibility with enzyme/substrate contact by
Reabilita??o vocal de laringectomizados com prótese traqueoesofágica
Costa, Claudiney C.;Rapoport, Abr?o;Chagas, José Francisco S.;Oliveira, Iara B.;Castro, Pedro de;Magna, Luiz Alberto;
Revista Brasileira de Otorrinolaringologia , 2001, DOI: 10.1590/S0034-72992001000500017
Abstract: we studied the complications resulting from the placement and use of the vocal prosthesis, assessment of voice quality and speech intelligibility using perceptive-auditory parameters before and after speech therapy and the period needed for vocal rehabilitation. from february 1999 to june 2000, a study was conducted on 23 patients who underwent total laryngectomy and were given a tracheoesophageal prosthesis like the blom-singer indwelling low pressure. study design: prospective clinical not randomized. material and method: the study consisted of 22 males and their ages ranged from 40 years to 80 years. the follow up period varied between 150 days to 462 days. one patient with the posterior commissure affected was at stadium i; stadium ii had one patient with a lesion in the subglottic region; stadium iii had 13 patients; stadium iv had four patients. the prosthesis was placed in seven patients concomitantly with the laryngectomy, while the placement was secondary in the remaining group. aim: we studied the complications resulting from the placement and use of the vocal prosthesis, assessment of voice quality and speech intelligibility using perceptive-auditory parameters before and after speech therapy and the period needed for vocal rehabilitation impossible. the success rating was 90% with 18 patients rehabilitated with the help of the prosthesis. the rehabilitation period varied between one day to 65 days. conclusions: the complications resulted from placement and use of this prosthesis did not hamper its success; the average time taken for voice acquisition was seven days, vocal quality and intelligibility of speech showed improvement after the phonoterapy without significant statistics difference and the secondary placement through new surgical technique by digestive endoscopy is better than the conventional technique.
Consumo hídrico e coeficiente de cultura da mamoneira na microrregi?o de Lavras, Minas Gerais
Rios, Gervásio F. A.;Carvalho, Luiz G. de;Magina, Flávio de C.;Castro Neto, Pedro;Silva, Bruno M.;Fraga, Ant?nio C.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2011, DOI: 10.1590/S1415-43662011001200009
Abstract: the study was carried out in order to evaluate the evapotranspiration (etc) and crop coefficient (kc) of castor bean by drip irrigation system, under the climatic conditions of lavras, minas gerais state, brazil, from 01/24 to 08/30/2008. the etc was determined by the energy balance according to the bowen ratio method and kc by the methods and recommendations of the fao-56 paper, from 02/14 to 06/03/2008, corresponding to phases i (growth), ii (vegetative), iii (fruiting) and iv (maturity). for this purpose, in the center of the experimental area, the sensors were installed to measure the temperature and relative humidity, at two levels above the crop canopy; the net radiation (rn) and the soil heat flux (g) at 0.08 m under the soil surface. the average etc values in phases i, ii and iii were 2.48, 2.68 and 3.04 mm d-1, respectively. the respective kc in these phases were 0.27, 0.46, 0.87 and 0.57 in maturity phase, within the limits and recommendations of the fao-56 paper.
Aspectos epidemiológicos e clínicos do escorpionismo na regi?o de Santarém, Estado do Pará, Brasil
Pardal, Pedro Pereira de Oliveira;Castro, Lívia Correa;Jennings, Erik;Pardal, Joseana Silva de Oliveira;Monteiro, Maria Rita de Cássia da Costa;
Revista da Sociedade Brasileira de Medicina Tropical , 2003, DOI: 10.1590/S0037-86822003000300006
Abstract: this is a descriptive and prospective study on epidemiological and clinical aspects of 72 scorpion accidents admitted to santarém municipal hospital, state of pará, brazil, from february 2000 to february 2001. only 8.3% brought the animal with them, identified as t. cambridgei. the majority of victims were male (83.3%). the mean age and the time of the medical help were respectively 33.6±18.3 years and 4.6±3.2 hours. the parts of the body most affected were the superior members (51.5%). local symptoms occurred in 91.7% cases and systemic manifestations in 98.6% of the accidents. the local symptoms included: paresthesia in 79.2% cases, pain in 52.8% and edema in 26.4%. among the systemic manifestations neurological disorders predominated in 97.2%, and the symptom of "electric shock" occurred in 88.9% patients. the most common neurological signs were: myoclonia (93%), dysmetria (86.1%), dysarthria (80.6%), and ataxia (70.8%). the accidents were classified as moderate in 76.4% without any serious cases. the specific anti-venom serum was not administered in 32.7% of the moderate cases, due to non-availability of the anti-venom serum at the time of attendance. the victims of scorpion envenomation notified at santarém, present a different clinical and regional behavior from previous reports in brazil and amazonia regions. the predominantly neurological picture has not previously been described in the brazilian literature.
A importancia da abordagem contextual no ensino de biosseguran?a
Pereira,Maria Eveline de Castro; Silva,Pedro César Teixeira; Costa,Marco Antonio Ferreira da; Jurberg,Claudia; Borba,Cintia de Moraes;
Ciência & Saúde Coletiva , 2012, DOI: 10.1590/S1413-81232012000600027
Abstract: biosafety is a field of knowledge that raises questions geared to genetically modified organisms that are linked to social and job-related employee protection. the educational process involves seeking to create a participative and transforming agent and must therefore transcend the simple concept of teaching. thus, it is important to contextualize biosafety within a constructive teaching strategy by identification of its core concepts - risk, hazard and accident - which allows each individual to understand how risk is perceived within society and dealt with in academia in order to add multiple skills to tackle the situation. understanding how the relationship between work and health and its consequences and effects are constructed over the course of time, makes it possible to train more critical and well prepared citizens to participate in decisions of a political and social nature that can influence their future.
Brazilian Propolis: Correlation between Chemical Composition and Antimicrobial Activity
Kelly Salom o,Paulo Roberto S. Pereira,Leila C. Campos,Cintia M. Borba,Pedro H. Cabello,Maria Cristina Marcucci,Solange L. de Castro
Evidence-Based Complementary and Alternative Medicine , 2008, DOI: 10.1093/ecam/nem058
Abstract: The chemical composition of ethanol extracts from samples of Brazilian propolis (EEPs) determined by HPLC and their activity against Trypanosoma cruzi, Staphylococcus aureus, Streptococcus pneumoniae, Klebisiella pneumoniae, Candida albicans, Sporothrix schenckii and Paracoccidioides brasiliensis were determined. Based on the predominant botanical origin in the region of samples' collection, the 10 extracts were separated into three groups: A (B. dracunculifolia + Auraucaria spp), B (B. dracunculifolia) and C (Araucaria spp). Analysis by the multiple regression of all the extracts together showed a positive correlation, higher concentrations leading to higher biological effect, of S. aureus with p-coumaric acid (PCUM) and 3-(4-hydroxy-3-(oxo-butenyl)-phenylacrylic acid (DHCA1) and of trypomastigotes of T. cruzi with 3,5-diprenyl-4-hydroxycinnamic acid derivative 4 (DHCA4) and 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran (DCBEN). When the same approach was employed for each group, due to the small number of observations, the statistical test gave unreliable results. However, an overall analysis revealed for group A an association of S. aureus with caffeic acid (CAF) and dicaffeoylquinic acid 3 (CAFQ3), of S. pneumoniae with CAFQ3 and monocaffeoylquinic acid 2 (CAFQ2) and of T. cruzi also with CAFQ3. For group B, a higher activity against S. pneumoniae was associated DCBEN and for T. cruzi with CAF. For group C no association was observed between the anitmicrobial effect and any component of the extracts. The present study reinforces the relevance of PCUM and derivatives, especially prenylated ones and also of caffeolyquinic acids, on the biological activity of Brazilian propolis.
Trabajo, producción y cerámica. Sociología de la alfarería Paracas: Ocucaje y Tajo (Costa Sur de Perú)
Castro-Martínez,Pedro V.; De La Torre,J. Carlos; Escoriza-Mateu,Trinidad; Godoy,M. Concepción; Lapi,Bárbara; Navarro,Israel; Zavala,J. César;
Estudios atacame?os , 2009, DOI: 10.4067/S0718-10432009000100009
Abstract: independent c14 dating was contrasted to chronological sequences based on "paracas pottery" series, evidencing the paradoxes, contradictions and incoherence in the relative chronologies derived from historico-cultural axioms. the conclusion addresses key aspects for a sociology of ocucaje and tajo ceramics, in the framework of the la puntilla project (nasca, lea).
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