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Queiroz AB, Lopes JB, Santos VP, Cruz PBAF, Fidelis RJR, Filho JSA, Passos LCS. Physician-Modified Endovascular Grafts for Zone-2 Thoracic Endovascular Aortic Repair. Aorta (Stamford) 2022; 10:13-19. [PMID: 35640582 PMCID: PMC9179216 DOI: 10.1055/s-0042-1742696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 07/02/2021] [Indexed: 06/15/2023]
Abstract
OBJECTIVE This study aims to describe our technique and early experience with physician-modified endovascular grafts (PMEGs) for aortic arch diseases in zone 2. We used a total endovascular technique based on a single fenestrated endograft to preserve left subclavian artery (LSA) patency. METHODS From December 2019 to August 2020, six consecutive patients with a variety of thoracic aortic diseases were treated with handmade fenestrated thoracic aortic grafts: four aortic dissections, one penetrating aortic ulcer, and one intramural hematoma. The planning, endograft modification, surgical technique, and follow-up of the patients were described. We evaluated immediate technical success and after 30 days, the LSA patency, Type-1 endoleak, and postoperative complications. RESULTS Thoracic endovascular aortic repair (TEVAR) was performed for zone 2 in all cases. Immediate technical success, defined as successful alignment of the LSA with a covered stent and no Type-1 endoleak, was achieved in all cases. Patients had a 30-day follow-up computed tomography, which demonstrated LSA patency and no Type-I endoleaks. To date, no strokes, left arm ischemia, paraplegia, or conversions to open surgery have been reported; one patient operated for acute Type B dissection died during the early follow-up. CONCLUSION TEVAR for zone 2 with a PMEG to maintain LSA patency achieved technical success and early durability. It is expected that with longer follow-up and a larger number of cases, these results will be confirmed.
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Affiliation(s)
- André B. Queiroz
- Centro de Doenças da Aorta - CDA, Division of Vascular and Endovascular Surgery, Cardiac Surgery, Cardiology and Anesthesia, Universidade Federal da Bahia, Hospital Ana Nery, Salvador-Bahia, Brazil
- Division of Vascular Surgery, Universidade Federal da Bahia, Hospital Universitário Professor Edgar Santos, Salvador-Bahia, Brazil
| | - Jackson B. Lopes
- Centro de Doenças da Aorta - CDA, Division of Vascular and Endovascular Surgery, Cardiac Surgery, Cardiology and Anesthesia, Universidade Federal da Bahia, Hospital Ana Nery, Salvador-Bahia, Brazil
| | - Vanessa P. Santos
- Division of Vascular Surgery, Universidade Federal da Bahia, Hospital Universitário Professor Edgar Santos, Salvador-Bahia, Brazil
| | - Pedro B. A. F. Cruz
- Centro de Doenças da Aorta - CDA, Division of Vascular and Endovascular Surgery, Cardiac Surgery, Cardiology and Anesthesia, Universidade Federal da Bahia, Hospital Ana Nery, Salvador-Bahia, Brazil
| | - Ronald J. R. Fidelis
- Division of Vascular Surgery, Universidade Federal da Bahia, Hospital Universitário Professor Edgar Santos, Salvador-Bahia, Brazil
| | - José S. Araújo Filho
- Centro de Doenças da Aorta - CDA, Division of Vascular and Endovascular Surgery, Cardiac Surgery, Cardiology and Anesthesia, Universidade Federal da Bahia, Hospital Ana Nery, Salvador-Bahia, Brazil
- Division of Vascular Surgery, Universidade Federal da Bahia, Hospital Universitário Professor Edgar Santos, Salvador-Bahia, Brazil
| | - Luiz C. S. Passos
- Centro de Doenças da Aorta - CDA, Division of Vascular and Endovascular Surgery, Cardiac Surgery, Cardiology and Anesthesia, Universidade Federal da Bahia, Hospital Ana Nery, Salvador-Bahia, Brazil
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Santos VP, Marques NSS, Maia PCSV, de Lima MAB, Franco LDO, de Campos-Takaki GM. Seafood Waste as Attractive Source of Chitin and Chitosan Production and Their Applications. Int J Mol Sci 2020; 21:ijms21124290. [PMID: 32560250 PMCID: PMC7349002 DOI: 10.3390/ijms21124290] [Citation(s) in RCA: 123] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/26/2020] [Accepted: 05/26/2020] [Indexed: 12/14/2022] Open
Abstract
Chitosan is a cationic polymer obtained by deacetylation of chitin, found abundantly in crustacean, insect, arthropod exoskeletons, and molluscs. The process of obtaining chitin by the chemical extraction method comprises the steps of deproteinization, demineralization, and discoloration. To obtain chitosan, the deacetylation of chitin is necessary. These polymers can also be extracted through the biological extraction method involving the use of microorganisms. Chitosan has biodegradable and biocompatible properties, being applied in the pharmaceutical, cosmetic, food, biomedical, chemical, and textile industries. Chitosan and its derivatives may be used in the form of gels, beads, membranes, films, and sponges, depending on their application. Polymer blending can also be performed to improve the mechanical properties of the bioproduct. This review aims to provide the latest information on existing methods for chitin and chitosan recovery from marine waste as well as their applications.
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Affiliation(s)
- Vanessa P. Santos
- Federal Rural University of Pernambuco, Recife 52171-900, Pernambuco, Brazil; (V.P.S.); (N.S.S.M.); (P.C.S.V.M.)
| | - Nathália S. S. Marques
- Federal Rural University of Pernambuco, Recife 52171-900, Pernambuco, Brazil; (V.P.S.); (N.S.S.M.); (P.C.S.V.M.)
| | - Patrícia C. S. V. Maia
- Federal Rural University of Pernambuco, Recife 52171-900, Pernambuco, Brazil; (V.P.S.); (N.S.S.M.); (P.C.S.V.M.)
| | - Marcos Antonio Barbosa de Lima
- Department of Microbiology, Federal Rural University of Pernambuco, Recife 52171-900, Pernambuco, Brazil; (M.A.B.d.L.); (L.d.O.F.)
| | - Luciana de Oliveira Franco
- Department of Microbiology, Federal Rural University of Pernambuco, Recife 52171-900, Pernambuco, Brazil; (M.A.B.d.L.); (L.d.O.F.)
| | - Galba Maria de Campos-Takaki
- Research Center for Environmental Sciences and Biotechnology, Catholic University Pernambuco, Recife 50050-590, Pernambuco, Brazil
- Correspondence: ; Tel.: +55-081-2119-4017
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Goulart RS, Vieira RAM, Daniel JLP, Amaral RC, Santos VP, Toledo Filho SG, Cabezas-Garcia EH, Tedeschi LO, Nussio LG. Effects of source and concentration of neutral detergent fiber from roughage in beef cattle diets: Comparison of methods to measure the effectiveness of fiber. J Anim Sci 2020; 98:skaa108. [PMID: 32386223 PMCID: PMC7210801 DOI: 10.1093/jas/skaa108] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 04/06/2020] [Indexed: 11/14/2022] Open
Abstract
Methods have been developed to measure the effectiveness of many roughages, but few evaluations have been conducted with tropical feeds. The objectives of this research were to determine the effectiveness of roughage sources based on bioassay and laboratory methods and identify the biological attributes of the diets that correlate with these methods. Six ruminally cannulated Nellore steers (408 ± 12 kg of BW) were randomly assigned to a 6 × 6 Latin square design within six diets: negative control diet (NC) with aNDF as 10% from corn silage (CS); positive control diet (PC) with aNDF as 20% from CS; and four diets containing 10% aNDF from CS and 10% aNDF from each of the following sources: sugarcane (SC), sugarcane bagasse (SCB), soybean hulls (SH), or low oil cottonseed hulls (LOCH). Physical effectiveness factor (pef, related to the physical characteristics of aNDF) and effectiveness factor (ef, related to the ruminal pH) were determined based on a linear model approach that uses a bioassay method in which CS aNDF was assumed to be the standard fiber source. Laboratory methods to estimate pef of roughage sources were based on the proportion of DM of roughage retained on a 1.18-mm sieve pef(>1.18 mm) or retained on the 8.0-mm Penn State Particle Separator screen pef(>8.0 mm). The pef calculated by the bioassay method (total chewing time and ruminal mat resistance) for CS, SCB, and SC were higher values (P < 0.05) compared with SH and LOCH. The pef(rumen mat) of SC and SCB were higher (P < 0.05) than that of CS, SH, and LOCH. The pef(rumen mat) of LOCH was 61% higher than SH. The ef(rumen pH) of SC and LOCH was higher (P < 0.05) than CS and SH. The pef(chewing, min/d), pef(chewing, min/kg of DM), pef(rumen mat), and ef(rumen pH) positively correlated with rumination time, total chewing time, and ruminal mat resistance (values from transit time in seconds). No correlation was observed (P > 0.05) between pef(>8.0 mm) and rumination time, chewing time, and ruminal pH. The pef calculated using the bioassay method as well as pef (>8.0 mm) were negatively correlated with rumen pH (P > 0.05). The values of the effectiveness of fiber sources obtained in this research can be used as a guideline for nutritionists aiming to replace roughage sources from tropical regions in beef cattle finishing diets. Under our conditions, the pef using the bioassay method or laboratory methods were not adequate in predicting ruminal pH.
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Affiliation(s)
- Rodrigo S Goulart
- Department of Animal Science, College of Animal Science and Food Engineering, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - Ricardo A M Vieira
- Laboratório de Zootecnia, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ, CEP, Brazil
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, São Paulo, Brazil
| | - Joao L P Daniel
- Department of Animal Science, State University of Maringá, Maringá Brazil
| | - Rafael C Amaral
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, São Paulo, Brazil
| | - Vanessa P Santos
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, São Paulo, Brazil
| | - Sergio G Toledo Filho
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, São Paulo, Brazil
| | - Edward H Cabezas-Garcia
- Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences, Umea, Sweden
| | - Luis O Tedeschi
- Department of Animal Science, Texas A&M University, College Station, TX
| | - Luiz Gustavo Nussio
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, São Paulo, Brazil
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Goulart RS, Vieira RAM, Daniel JLP, Amaral RC, Santos VP, Toledo Filho SG, Cabezas-Garcia EH, Tedeschi LO, Nussio LG. Effects of source and concentration of neutral detergent fiber from roughage in beef cattle diets on feed intake, ingestive behavior, and ruminal kinetics. J Anim Sci 2020; 98:skaa107. [PMID: 32386225 PMCID: PMC7344115 DOI: 10.1093/jas/skaa107] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 04/06/2020] [Indexed: 11/13/2022] Open
Abstract
The objectives of this research were to evaluate the effects of source and concentration of α-amylase-treated neutral detergent fiber (aNDF) from roughage on feed intake, ingestive behavior, and ruminal kinetics in beef cattle receiving high-concentrate diets. Six ruminally cannulated Nellore steers (408 ± 12 kg of body weight) were randomly assigned to a 6 × 6 Latin square design with six diets: 10% aNDF from corn silage (10CS); 20% aNDF from corn silage (20CS); or four diets containing 10% aNDF from corn silage and 10% aNDF from one of the following sources: sugarcane (SC), sugarcane bagasse (SCB), soybean hulls (SH), or low oil cottonseed hulls (LOCH). The parameters of passage and degradation kinetics were estimated based on a two-compartmental model with gamma- and exponential-distributed residence times. The nonlinear models were fitted by nonlinear least squares, and a linear mixed-effects model was fitted to all variables measured from the Latin square design that were related to intake, digestibility, digestion kinetic parameters, and residence times. Mean particle size (MPS) between roughage sources (CS, SCB, and SC) and coproducts (SH and LOCH) was affected (P < 0.05). Dry matter intake (DMI) was not affected (P > 0.05) by 20CS, SC, SH, or LOCH. Steers fed 20CS or LOCH diets had 16% and 20% greater DMI, respectively, (P < 0.05) than steers fed 10CS diet. Steers fed SCB consumed the least dry matter (DM). The SH and LOCH diets had lower MPS values (about 8.77 mm) in comparison to 20CS, SCB, and SC diets (about 13.08 mm) and, consequently, affected (P < 0.05) rumen content, ruminal in situ disappearance, nutrient digestibility, and solid fractional passage rate. Chewing time was affected (P < 0.05) by roughage sources and concentration. Lower values of distance travel inside the rumen (min/cm) were observed (P < 0.05) for the SCB and SC diets in comparison with any other diet. Except for SCB, there was no difference (P > 0.05) in rumen fill, among other treatments. Mean daily ruminal pH was not affected (P > 0.05) by 20CS, SCB, SC, and LOCH diets, and it ranged from 6.1 to 6.23. Total short-chain fatty acids concentration was affected (P < 0.05) by roughage source and concentration. Based on our results, we recommend that under Brazilian finishing diets, replacing roughage sources, except for SCB, based on aNDF concentration of the roughage in high-concentrate diets containing finely ground flint corn does not affect DMI.
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Affiliation(s)
- Rodrigo S Goulart
- Department of Animal Science, College of Animal Science and Food Engineering, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - Ricardo A M Vieira
- Laboratório de Zootecnia, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ, CEP, Brazil
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, São Paulo, Brazil
| | - Joao L P Daniel
- Department of Animal Science, State University of Maringá, Maringá, Brazil
| | - Rafael C Amaral
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, São Paulo, Brazil
| | - Vanessa P Santos
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, São Paulo, Brazil
| | - Sergio G Toledo Filho
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, São Paulo, Brazil
| | - Edward H Cabezas-Garcia
- Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences, Umea, Sweden
| | - Luis O Tedeschi
- Department of Animal Science, Texas A&M University, College Station, TX
| | - Luiz G Nussio
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, São Paulo, Brazil
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Marques NSAA, da Silva IGS, Cavalcanti DL, Maia PCSV, Santos VP, Andrade RFS, Campos-Takaki GM. Eco-Friendly Bioemulsifier Production by Mucor circinelloides UCP0001 Isolated from Mangrove Sediments Using Renewable Substrates for Environmental Applications. Biomolecules 2020; 10:biom10030365. [PMID: 32120912 PMCID: PMC7175160 DOI: 10.3390/biom10030365] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 02/14/2020] [Accepted: 02/14/2020] [Indexed: 01/26/2023] Open
Abstract
The successful production of a biosurfactant is dependent on the development of processes using low cost raw materials. In the present work, an economically attractive medium composed of corn steep liquor and waste cooking oil was formulated to maximize the production of bioemulsifier by Mucor circinelloides UCP0001. A central rotational composite design was applied to statistical validation of the production. The emulsifying properties, stability under extreme conditions, its toxicity character, and the characterization of the bioemulsifier were determined. The best condition for biomolecule synthesis occurred in the assay 2 containing 4% of corn steep liquor and 3% waste soybean oil and exhibited 100% emulsification index for canola oil and petroleum, as well as excellent emulsifying activity for canola oil and burned engine oil. The nutritional factors studied showed statistical relevance, since all linear, quadratic effects and their interactions were significant. The bioemulsifier showed 2.69 g/L yield and the chemical character of the molecule structure was identified by FT-IR (Fourier Transform Infrared) spectroscopy. The bioemulsifier showed no toxicity to Artemia salina and Chlorella vulgaris. Stable emulsions were obtained under extreme conditions of temperature, pH, and salinity. These findings contribute to understanding of the relationship between production, physical properties, chemical composition, and stability of bioemulsifier for their potential applications in biotechnology, such as bioremediation of hydrocarbon-contaminated soil and water.
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Affiliation(s)
- Nathália S. A. A. Marques
- Northeast Biotechnology Network, Federal Rural University of Pernambuco, Recife 52171-900, Pernambuco, Brazil; (N.S.A.A.M.); (I.G.S.d.S.); (P.C.S.V.M.); (V.P.S.)
- Doctorate Program in Biological Sciences, Federal University of Pernambuco, Recife 50870-420, Pernambuco, Brazil;
- Nucleus of Research in Environmental Sciences and Biotechnology, Catholic University of Pernambuco, Recife 50050-590, Pernambuco, Brazil;
| | - Israel G. Sales da Silva
- Northeast Biotechnology Network, Federal Rural University of Pernambuco, Recife 52171-900, Pernambuco, Brazil; (N.S.A.A.M.); (I.G.S.d.S.); (P.C.S.V.M.); (V.P.S.)
| | - Davi L. Cavalcanti
- Doctorate Program in Biological Sciences, Federal University of Pernambuco, Recife 50870-420, Pernambuco, Brazil;
- Nucleus of Research in Environmental Sciences and Biotechnology, Catholic University of Pernambuco, Recife 50050-590, Pernambuco, Brazil;
| | - Patrícia C. S. V. Maia
- Northeast Biotechnology Network, Federal Rural University of Pernambuco, Recife 52171-900, Pernambuco, Brazil; (N.S.A.A.M.); (I.G.S.d.S.); (P.C.S.V.M.); (V.P.S.)
- Doctorate Program in Biological Sciences, Federal University of Pernambuco, Recife 50870-420, Pernambuco, Brazil;
- Nucleus of Research in Environmental Sciences and Biotechnology, Catholic University of Pernambuco, Recife 50050-590, Pernambuco, Brazil;
| | - Vanessa P. Santos
- Northeast Biotechnology Network, Federal Rural University of Pernambuco, Recife 52171-900, Pernambuco, Brazil; (N.S.A.A.M.); (I.G.S.d.S.); (P.C.S.V.M.); (V.P.S.)
- Doctorate Program in Biological Sciences, Federal University of Pernambuco, Recife 50870-420, Pernambuco, Brazil;
- Nucleus of Research in Environmental Sciences and Biotechnology, Catholic University of Pernambuco, Recife 50050-590, Pernambuco, Brazil;
| | - Rosileide F. S. Andrade
- Nucleus of Research in Environmental Sciences and Biotechnology, Catholic University of Pernambuco, Recife 50050-590, Pernambuco, Brazil;
| | - Galba M. Campos-Takaki
- Nucleus of Research in Environmental Sciences and Biotechnology, Catholic University of Pernambuco, Recife 50050-590, Pernambuco, Brazil;
- Correspondence: ; Tel.: +55-81-21194017; Fax: +55-81-2119404
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Daniel JLP, Amaral RC, Goulart RS, Zopollatto M, Santos VP, Toledo Filho SG, Cabezas-Garcia EH, Lima JR, Santos MC, Nussio LG. Short-term effects of silage volatile compounds on feed intake and digestion in beef cattle. J Anim Sci 2013; 91:2321-31. [PMID: 23478815 DOI: 10.2527/jas.2012-5657] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Two experiments were conducted to evaluate whether fermentation end products in silage affect intake and digestion in beef cattle. Six rumen-cannulated Nellore steers were randomly assigned to a replicated 3 × 3 Latin square design with 14-d periods. Each period consisted of 9 d for adaptation and 5 d for sample collection. Steers were housed in a tie-stall barn and individually fed once daily at 0800 h. The dietary treatments in Exp. 1 were as follows: 60% corn silage plus 40% concentrate (CON), 60% corn silage with added ethanol (2.8% on a DM basis) and 40% concentrate (ET), and 60% corn silage with added lactic acid (5.4% on a DM basis) and 40% concentrate (LA). The DMI was similar (P = 0.41) across treatments (average 11.7 kg/d); however, the LA treatment increased the ruminal pH (P = 0.01) and decreased the acetate:propionate ratio (P < 0.01). Diet digestibility decreased by 2.2 to 2.5 percentage units when the DM content was determined by oven drying (at 105°C) rather than by toluene distillation. The treatments in Exp. 2 were as follows: 75% sugarcane silage with no volatile fraction (oven dried at 60°C and rehydrated) and 25% concentrate (75D), 75% sugarcane silage (original moisture content) and 25% concentrate (75W), and 40% sugarcane silage and 60% concentrate (40W). Approximately 21% of the DM content of sugarcane silage consisted of volatile compounds. The presence of these compounds did not alter the DMI (P = 0.36) but did increase both the acetate:propionate ratio (P < 0.01) and the fractional absorption rates of valerate (P < 0.01) and ethanol (P = 0.02) in the empty reticulorumen. The 40W diet led to a greater DMI (40W = 9.79 vs. 75W = 6.19 kg/d; P < 0.01), which altered most of the measured variables traditionally associated with high-concentrate diets. As in Exp. 1, diet digestibility decreased by 1.5 to 5.4 units when the DM content was determined by oven drying at 105°C rather than by toluene distillation. In this short-term study, volatile compounds did not inhibit the DMI or the digestion process of the animals. On the contrary, volatile compounds contributed to the energy content of the silage, composing up to 10% of the energy value as determined by digestibility. Due to the short experimental periods, the results from this study should be interpreted with caution.
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Affiliation(s)
- J L P Daniel
- Department of Animal Science, University of São Paulo, Luiz de Queiroz College of Agriculture, Piracicaba, SP, Brazil, 13418-900.
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Silva B, Figueiredo H, Santos VP, Pereira MFR, Figueiredo JL, Lewandowska AE, Bañares MA, Neves IC, Tavares T. Reutilization of Cr-Y zeolite obtained by biosorption in the catalytic oxidation of volatile organic compounds. J Hazard Mater 2011; 192:545-553. [PMID: 21684081 DOI: 10.1016/j.jhazmat.2011.05.056] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 05/13/2011] [Accepted: 05/16/2011] [Indexed: 05/30/2023]
Abstract
This work aims at the reutilization of a Cr-loaded NaY zeolite obtained by biorecovery of chromium from water as catalyst in the oxidation of volatile organic compounds (VOC). Cr-NaY catalysts were obtained after biosorption of Cr(VI) using a bacterium, Arthrobacter viscosus, supported on the zeolite. The biosorption experiments were conducted at different pH values in the range 1-4. The catalysts were characterized by several techniques, namely ICP-AES, SEM-EDS, XRD, XPS, Raman, H(2)-TPR and N(2) adsorption. The zeolite obtained at pH 4 has the highest content of chromium, 0.9%, and was selected as the best catalyst for the oxidation of different VOC, namely ethyl acetate, ethanol and toluene. For all VOC tested, the catalyst with chromium showed higher activity and selectivity to CO(2), in comparison with the starting zeolite NaY. The presence of chromium shifted also the reaction pathways. In terms of selectivity to CO(2), the following sequence was observed: ethyl acetate>toluene>ethanol.
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Affiliation(s)
- B Silva
- IBB - Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
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Santos VP, Pereira MFR, Órfão JJM, Figueiredo JL. Mixture effects during the oxidation of toluene, ethyl acetate and ethanol over a cryptomelane catalyst. J Hazard Mater 2011; 185:1236-1240. [PMID: 21044815 DOI: 10.1016/j.jhazmat.2010.10.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2010] [Revised: 09/24/2010] [Accepted: 10/09/2010] [Indexed: 05/30/2023]
Abstract
The catalytic oxidation of two-component VOC mixtures (ethanol, ethyl acetate and toluene) was studied over cryptomelane. Remarkable mixture effects were observed on the activity and the selectivity. Toluene inhibits both ethyl acetate and ethanol oxidation, this effect being more evident in the case of ethyl acetate. For instance, the temperature for 100% conversion is about 210 °C when ethyl acetate is oxidised alone, and 250 °C or higher, when it is oxidised in mixtures with toluene. On the contrary, toluene oxidation is only slightly inhibited by the presence of ethyl acetate, while the presence of ethanol has a promoting effect. Concerning the mixtures of ethyl acetate and ethanol, both compounds have a mutual inhibitory effect, which is more evident in the case of ethyl acetate (the temperature for 100% conversion of ethyl acetate is about 45 °C higher when ethyl acetate is oxidised in mixtures with ethanol, while in the case of ethanol the corresponding increase is only 10 °C).
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Affiliation(s)
- V P Santos
- Laboratório de Catálise e Materiais, Laboratório Associado LSRE/LCM, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr Roberto Frias, 4200-465 Porto, Portugal.
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Santos VP, Pereira MFR, Faria PCC, Orfão JJM. Decolourisation of dye solutions by oxidation with H(2)O(2) in the presence of modified activated carbons. J Hazard Mater 2009; 162:736-742. [PMID: 18584951 DOI: 10.1016/j.jhazmat.2008.05.090] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 05/18/2008] [Accepted: 05/19/2008] [Indexed: 05/26/2023]
Abstract
The decolourisation of dye solutions by oxidation with H(2)O(2), using activated carbon as catalyst, is studied. For this purpose, three different samples, mainly differing in the respective surface chemistries, were prepared and characterized. Moreover, this work involved three pH levels, corresponding to acid, neutral and alkaline solutions, and six dyes belonging to several classes. The catalytic decolourisation tests were performed in a laboratorial batch reactor. Adsorption on activated carbon and non-catalytic peroxidation kinetic experiments were also carried out in the same reactor, in order to compare the efficiencies of the three processes. The non-catalytic reaction is usually inefficient and, typically, adsorption presents a low level of decolourisation. In these cases, the combination of activated carbon with hydrogen peroxide may significantly enhance the process, since the activated carbon catalyses the decomposition of H(2)O(2) into hydroxyl radicals, which are very reactive. Based on the experiments with the different activated carbon samples, which have similar physical properties, it is proved that the surface chemistry of the catalyst plays a key role, being the basic sample the most active. This is discussed considering the involvement of the free electrons on the graphene basal planes of activated carbon as active centres for the catalytic reaction. Additionally, it is shown that the decolourisation is enhanced at high pH values, and a possible explanation for this observation, based on the proposed mechanism, is given.
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Affiliation(s)
- V P Santos
- Laboratório de Catálise e Materiais (LCM), Laboratório Associado LSRE/LCM, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
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Santos VP. [Streptococcal infections]. J Pediatr (Rio J) 1999; 75 Suppl 1:S103-14. [PMID: 14685488 DOI: 10.2223/jped.377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVES: To review the main diseases caused by the different strains of streptococcus, and to discuss the practical aspects of clinical diagnosis and the range of therapeutic treatments. METHODOLOGY: A review of the literature and a selection of the most meaningful themes for the pediatricians. RESULTS: The majority of the streptococcus described here are susceptible and have sensibility to penicillin. Different kinds of treatments aim at a better support to the offered scheme, including smaller amounts of doses per day, short-lived treatment and lowcost. CONCLUSION: Streptococcus infections are very frequently seen in the pediatrician's office. It is important to make an accurate diagnosis, and if possible a more simplified therapeutic treatment.
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Affiliation(s)
- V P Santos
- Faculdade de Medicina do ABC, São Paulo, SP, Brazil
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Santos VP. The importance of sound dental health. Dent Mirror (Quezon City) 1965; 2:15 passim. [PMID: 5228685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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