RESUMO
The gas-phase reactions of noble gas (Ng) cations, namely Kr+ and Xe+, with SF6 were investigated experimentally by Fourier transform ion cyclotron resonance mass spectrometry and computationally using RI-MP2 and BCCD(T) methods. The study revealed a new interaction between Kr+ and neutral SF6 that gave rise to a new cationic, weakly bound complex of Kr, [KrSF5]+, although the major reaction channel was dissociative electron transfer to yield SF5+ and {Kr, F}. Experimental studies examined the formation and stability of the new species and computational studies addressed the energetics of the reaction and indicated that [KrSF5]+ is stable by ca. 1 kcal mol-1. The same computational approach was used to examine the reaction of Xe+ with SF6 and showed it to be thermodynamically unfavourable by ca. 35 kcal mol-1, confirming the non-observation of reaction in the mass spectrometry experiments. An analysis of the bonding in [KrSF5]+ clearly showed that it is a non-covalently bound species, while in its presumed precursor [KrSF6]+ a partially covalent Kr-F bond is present.
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Searching in the Web of Knowledge for "ionic liquids" AND "luminescence" AND "lanthanide", around 260 entries can be found, of which a considerable number refer solely or primarily to europium (90%, ~234). Europium has been deemed the best lanthanide for luminescent applications, mainly due to its efficiency in sensitization, longest decay times, and the ability to use its luminescence spectra to probe the coordination geometry around the metal. The remaining lanthanides can also be of crucial importance due to their different colors, sensitivity, and capability as probes. In this manuscript, we intend to shed some light on the existing published work on the remaining lanthanides. In some cases, they appear in papers with europium, but frequently in a subordinate position, and in fewer cases then the main protagonist of the study. All of them will be assessed and presented in a concise manner; they will be divided into two main categories: lanthanide compounds dissolved in ionic liquids, and lanthanide-based ionic liquids. Finally, some analysis of future trends is carried out highlighting some future promising fields, such as ionogels.
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The magnetic properties of layered dysprosium hydroxides, both diluted in the diamagnetic yttrium analogous matrix (LYH:0.04Dy), and intercalated with 2,6-naphthalene dicarboxylate anions (LDyH-2,6-NDC), were studied and compared with the recently reported undiluted compound (LDyH = Dy8(OH)20Cl4·6H2O). The Y diluted compound reveals a single-molecule magnet (SMM) behavior of single Dy ions, with two distinct slow relaxation processes of the magnetization at low temperatures associated with the two main types of Dy sites, 8- and 9-fold coordinated. Only one relaxation process is observed in both undiluted LDyH and intercalated compounds as a consequence of dominant ferromagnetic Dy-Dy interactions, both intra- and interlayer. Semiempirical calculations using a radial effect charge (REC) model for the crystal field splitting of the Dy levels are used to explain data in terms of contributions from the different Dy sites. The dominant ferromagnetic interactions are explained in terms of orientations of easy magnetization axes obtained by REC calculations together with the sign of the superexchange expected from the Dy-O-Dy angles.
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The aim of this study was to characterize the acute complications that required hospitalization in children under 5 years with Sickle Cell Disease. The population included 70 patients, 64% of African ascendency and 95.7% homozygotic for the HbS. We analyzed data from 337 hospitalizations. The first hospitalization occurred before 12 months in 38.6% and the average hospital admission per child was 3.92. The mean duration per hospitalization was 5.36 days. The most common diagnosis was vaso-occlusive crisis (36.8%) followed by fever, upper airway infections, bacterial pneumonia and splenic sequestration. Hemoglobin values at admission were between 6 and 7 g/dL in 22.3%, with 44.2% requiring at least 1 blood transfusion. There are several acute complications of SCD, being vaso-occlusive crisis the most common. Splenic sequestration generally occurs during the first 2 years and is associated with the need of transfusion. They represent a significant burden, with each child spending approximately 3 weeks hospitalized.
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Here we discuss the influence of two different cations on the emissive properties of the highly emissive [Eu(fod)4]- anion. The studied Eu(III) salts were [C16Pyr][Eu(fod)4] (1), and the previously reported [Chol][Eu(fod)4]. C16Pyr stands for N-cetylpyridinium, Chol for cholinium and fod for 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate. 1 is classified as ionic liquid, with melting point close to 60 °C, and presented a luminescence quantum yield of (Ï) 100%. Ultrabright emissive photopolymers were obtained for the first time using polysulfone as the host matrix. The films were prepared with incorporation of 10% (w/w) of 1 and [Chol][Eu(fod)4] in the polymeric matrix, which improved its thermal stability. Additionally, the luminescence of CholEu(fod)4/PSU presented a strong temperature dependence with a ratiometric thermal behavior.
RESUMO
An emissive europium(III) complex [C2 mim][Eu(fod)4 ] (1; C2 mim=1-ethyl-3-methyl-imidazolium; fod=1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate) was prepared. The complex shows ratiometric thermal behaviour up to 155 °C. These unusual temperature-dependent properties arise from a solid-solid phase transition that promotes increased contact between the anion and the cation, affecting the emission profile of the emissive anion in two different ratiometric relations. A ultrabright and flexible emissive photopolymer film was obtained using polysulfone (PSU) as the host matrix of 10 % (w/w) of 1, that also induced changes on the lanthanide emissive profile with temperature. A temperature-responsive luminescent film 1/PSU is sensitivr to heating between 100 and 155 °C. Also, the emission lifetime of 1 was not affected by confinement in PSU, while its emission quantum yield was reduced from 82 to 59 %.
RESUMO
An unusual thermally sensitive anion-cation interaction, which is characteristic of the anion [Eu(FOD)4 ]- , occurs in the complex [CHOL][Eu(FOD)4 ] (1; CHOL=choline; FOD=1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedionate) and affects both quantum yield and thermochromic behavior. This prompted the design of an Eu3+ -based ratiometric thermometer that functions at temperatures up to 95 °C through a thermally excited state absorption of the Eu3+ ion. The reusable temperature-sensitive luminescent complex showed a range of relative sensitivity between 0.45 % C-1 at 25 °C, with an increase to 7.0 % C-1 at 95 °C. Confinement of compound 1 in a transparent film of polysulfone resulted in a higher thermal stability of 1 while its luminescence showed a strong temperature dependence.
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The use of ionizing radiation processing technologies has proven to be one of the most versatile ways to prepare a wide range of membranes with specific tailored functionalities, thus enabling them to be used in a variety of industrial, environmental, and biological applications. The general principle of this clean and environmental friendly technique is the use of various types of commercially available high-energy radiation sources, like 60Co, X-ray, and electron beam to initiate energy-controlled processes of free-radical polymerization or copolymerization, leading to the production of functionalized, flexible, structured membranes or to the incorporation of functional groups within a matrix composed by a low-cost polymer film. The present manuscript describes the state of the art of using ionizing radiation for the preparation and functionalization of polymer-based membranes for biomedical and environmental applications.
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The diverse reactivity of [LnO2(NO3)2]- complexes with water in the gas phase, for Ln = Ce, Pr and Nd, examined in a quadrupole ion trap and complemented by ab initio computations, illuminates the chemical stability of Pr in the unusual +5 oxidation state.
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Oxomolybdenum(VI) complexes of 3,4-dihydroxybenzoic acid (3,4-H 2dhb) have been incorporated into layered double hydroxides (LDHs) by treatment of the LDH-nitrate (Zn-Al, Mg-Al) or LDH-chloride (Li-Al) precursors with aqueous or water/ethanol solutions of the complex (NMe 4) 2[MoO 2(3,4-dhb) 2].2H 2O at 50 or 100 degrees C. The texture and chemical composition of the products were investigated by elemental analysis and scanning electron microscopy (SEM) with coupled energy dispersive spectroscopy (EDS). Microanalysis for N and EDS analysis for Cl showed that at least 90% of nitrate or chloride ions were replaced during the ion exchange reactions. The final Mo content in the materials varied between 6.5 and 11.6 wt %. Mo K-edge EXAFS analysis, supported by IR, Raman, UV-vis, and (13)C{ (1)H} CP/MAS NMR spectroscopic studies, showed the presence of cointercalated [MoO 2(3,4-dhb) 2] ( m- ) and [Mo 2O 5(3,4-dhb) 2] ( m- ) complexes in proportions that depend on the type of LDH support and the reaction conditions. The binuclear bis(catecholate) complex, with a Mo...Mo separation of 3.16 A, was the major species intercalated in the Zn-Al and Li-Al products prepared using only water as solvent. The X-ray powder diffraction (XRPD) patterns of all the Mo-containing LDHs showed the formation of an expanded phase with a basal spacing around 15.4 A. High-resolution synchrotron XRPD patterns were indexed with hexagonal unit cells with a c-axis of either 30.7 (for Li-Al-Mo LDHs) or 45.9 A (for a Zn-Al-Mo LDH). Fourier maps ( F obs) calculated from the integrated intensities extracted from Le Bail profile decompositions indicated that the binuclear guest species are positioned such that the Mo --> Mo vector is parallel to the host layers, and the overall orientation of the complex is perpendicular to the same layers. The thermal behavior of selected materials was studied by variable-temperature XRPD, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC).
RESUMO
Three layered lanthanide hydroxides (LLHs), with the general formula Ln8(OH)20Cl4·nH2O (Ln = Tb (1), Ho (2), Er (3)), were prepared and magnetically characterized both as pure compounds and diluted within a yttrium diamagnetic matrix, LYH : xLn, LYH : 0.044Tb (1'), LYH : 0.045Ho (2'), and LYH : 0.065Er (3'). This study was complemented with theoretical calculations in order to understand the electronic configuration and the contributions to the slow relaxation behavior. In the pure compounds dominant 3D ferromagnetic interactions are observed, with a small magnetization hysteresis at 1.8 K for 1, while the magnetically diluted solid solutions display slow relaxation of magnetization at low temperatures.
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The efficient separation of gases has industrial, economic, and environmental importance. Here, we report the improvement in gas separation performance of a polyimide-based matrix (Matrimid®5218) filled with a Cu-based metal organic framework [MOF, Cu3(BTC)2] with two different ionic liquids (ILs) confined within the pores. The chosen ILs are commonly used in gas solubilization, 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) and 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][OTf]), and the incorporation of the [EMIM][BF4]@Cu-BTC and [EMIM][OTf]@Cu-BTC composites in Matrimid®5218 proved to be an efficient strategy to improve the permeability and selectivity toward CO2/N2 and CO2/CH4 mixtures.
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We report the first example of an observable and reversible case of thermochromism due to the interaction of an alkylphosphonium (P6,6,6,14)+ with a ß-diketonate (1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate-fod) of an europium(iii) tetrakis-ß-diketonate room temperature ionic liquid. This thermochromism is characterized by the conversion of a light yellow viscous liquid, at room temperature, to a reddish substance close to 80 °C. The reversibility of this optical effect was highlighted by the thermal stability of the Eu(iii) complex.
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The tetrahedral triphenylsiloxy complex MoO(2)(OSiPh(3))(2) (1) and its Lewis base adduct with 2,2'-bipyridine, MoO(2)(OSiPh(3))(2)(bpy) (2), were prepared and characterised by IR/Raman spectroscopy, and thermogravimetric analysis. Both compounds catalyse the epoxidation of cis-cyclooctene at 55 degrees C using tert-butylhydroperoxide (t-BuOOH) is decane as the oxidant, giving 1,2-epoxycyclooctane as the only product. The best results were obtained in the absence of a co-solvent (other than the decane) or in the presence of 1,2-dichloroethane, while much lower activities were obtained when hexane or acetonitrile were added. With no co-solvent, catalyst 1 (initial activity 272 mol x molMo(-1) x h(-1)for a catalyst:substrate: oxidant molar ratio of 1:100:150) is much more active than 2(initial activity 12 mol x molMo(-1) x h(-1)). The initial reaction rates showed first order dependence with respect to the initial concentration of olefin. With respect to the initial amount of oxidant, the rate order dependence for 1 (1.9) was higher than that for 2 (1.6).The dependence of the initial reaction rate on reaction temperature and initial amount of catalyst was also studied for both catalysts. The lower apparent activation energy of 1 (11 kcal x mol(-1)) as compared with 2 (20 kcal x mol(-1)) is in accordance with the higher activity of the former.
Assuntos
2,2'-Dipiridil/química , Molibdênio/química , Catálise , Espectroscopia de Ressonância Magnética , Espectrofotometria Infravermelho , Análise Espectral RamanRESUMO
Three new crystalline metal-organic frameworks have been prepared from the reaction of uranyl nitrate with nitrilotris(methylphosphonic acid) [H6nmp, N(CH2PO3H2)3], 1,4-phenylenebis(methylene)diphosphonic acid [H4pmd, C6H4(PO3H2)2], and (benzene-1,3,5-triyltris(methylene))triphosphonic acid [H6bmt, C6H3(PO3H2)3]. Compound [(UO2)2F(H3nmp)(H2O)]·4H2O (I) crystallizes in space group C2/c, showing two crystallographically independent uranyl centres with pentagonal bipyramidal coordination geometries. While one metal centre is composed of a {(UO2)O3(µ-F)}2 dimer, the other comprises an isolated {(UO2)O5} polyhedron. Compound [(UO2)(H2pmd)] (II) crystallizes in space group P21/c, showing a centrosymmetric uranyl centre with an octahedral {(UO2)O4} coordination geometry. Compound [(UO2)3(H3bmt)2(H2O)2]·14H2O (III) crystallizes in space group P\bar 1, showing two crystallographically independent uranyl centres. One uranyl centre is a {(UO2)O5} pentagonal bipyramid similar to that in (I), while the other is a {(UO2)O4} centrosymmetric octahedron similar to that in (II). Compounds (I) and (III) contain solvent-accessible volumes accounting for ca 23.6 and 26.9% of their unit-cell volume, respectively. In (I) the cavity has a columnar shape and is occupied by disordered water molecules, while in (III) the cavity is a two-dimensional layer with more ordered water molecules. All compounds have been studied in the solid state using FT-IR spectroscopy. Topological studies show that compounds (I) and (III) are trinodal, with 3,6,6- and 4,4,6-connected networks, respectively. Compound (II) is instead a 4-connected uninodal network of the type cds.
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Reaction of [U{(SiMe2NPh)3-tacn}Cl] with LiNEt2 or LiNPh2 affords the corresponding amide compounds, [U{(SiMe2NPh)3-tacn}(NR2)] (R = Et (1), R = Ph (2)). The complexes have been fully characterized by spectroscopic methods and the solid-state structure of 1 was determined by single-crystal X-ray diffraction analysis. The six nitrogen atoms of the tris(dimethylsilylanilide)triazacyclononane ligand are in a trigonal prismatic configuration with the nitrogen atom of the diethylamide ligand capping one of the trigonal faces of the trigonal prism. Crystallization of 2 from CH3CN solution gave crystals of the six-membered heterocycle [U{(SiMe2NPh)3-tacn}{kappa2-(HNC(Me))2CC[triple bond]N}] (3). The reactivity of the amides was investigated. Both compounds undergo acid-base reactions with protic substrates such as HOC6H2-2,4,6-Me3, 3,5-Me2pzH (pz = pyrazolyl) and HSC5H4N to give the corresponding [U{(SiMe2NPh)3-tacn}X] (X = OC6H2-2,4,6-Me3 (4), 3,5-Me2pzH (5), kappa2-SC5H4N (6)) complexes. The solid-state structures of and were determined by single-crystal X-ray diffraction and revealed that the compounds are eight-coordinate with dodecahedral geometry.
RESUMO
Reaction of yttrium and lanthanide trichlorides (Ln = La, Eu, Yb) with 1 equiv of the trisodium salt of 1,4,7-tris(dimethylsilylaniline)-1,4,7-triazacyclononane (Na(3)[(SiMe(2)NPh)(3)-tacn](THF)(2)) gives good yields of the compounds [M[(SiMe(2)NPh)(3)-tacn]] (M = Y (1), Eu (3), Yb (4)) and [La[(SiMe(2)NPh)(3)-tacn](THF)] (2). Reduction of 3 with Na/Hg followed by recrystallization in the presence of diglyme yielded crystals of [Eu[(SiMe(2)NPh)(3)-tacn]][Na(diglyme)(2)] (5). Synthesis of the uranium(III) complex [U[(SiMe(2)NPh)(3)-tacn]] (6) is achieved by reaction of 1 equiv of Na(3)[(SiMe(2)NPh)(3)-tacn](THF)(2) with uranium triiodide. The U(IV) complexes, [U[(SiMe(2)NPh)(3)-tacn]X] (X = Cl (7); I (8)), were prepared via oxidation of 6 with benzyl chloride or I(2), but salt metathesis from UCl(4) provided a higher yield route for 7. The solid-state structures of 1-7 were determined by single-crystal X-ray diffraction. The ligand [(SiMe(2)NPh)(3)-tacn] generates a trigonal prismatic coordination environment for the metal center in the neutral complexes 1, 3, 4, and 6 and the ionic 5. In 2 the six nitrogen atoms of the ligand are in a trigonal prismatic configuration with the oxygen atom of the THF capping one of the triangular faces of the trigonal prism. In 7 the coordination geometry around the uranium atom is best described as bicapped trigonal bipyramidal.
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Trata-se de um estudo com o objetivo de apresentar e analisar propostas de emendas à Lei nº 7.498/86, que regulamenta a profissão de enfermagem como um exercício crítico acadêmico e, talvez, assim contribuir para o aperfeiçoamento dessa lei, sugerindo modificações para sua atualização e consolidação da enfermagem como profissão autônoma e liberal. Essas propostas surgiram no bojo das discussões geradas na disciplina de Análise Ético-Legal, no Curso de Pós-Graduação em Enfermagem da Universidade de São Paulo, e os documentos estudados foram a LEPE nº 7.498/96 e o Decreto nº 94.406/87 que regulamentam o exercício da Enfermagem. A metodologia empregada foi o Estudo de Caso, com base na contextualização histórico-social e ético-legal, fundamentada em fontes legais escritas, no Conselho Federal de Enfermagem e em outras organizações internacionais.
This study aims to present and analyze amendment proposals concerning the law 7498/86, which regulates the nursing profession. Through a critical and academic exercise we intend to contribute with the improvement of this law by suggesting modifications for its update, as well as to help in the consolidation of nursing as an autonomous and liberal profession. Such proposals emerged during discussions in Nursing Ethical and legal Analysis, a discipline from the post-graduate program of the Nursing School of the University of São Paulo. Law n. 7.486/1986 and Decree n. 94406/1987 were studied, both related to Nursing Professional Practice. The Case Study methodology was applied, with basis on a history-social and ethic-legal context. References were obtained from the Brazilian Nursing Council and from other international organizations.
Se trata de un estudio realizado como un ejercicio critico académico con el objetivo de presentar y analizar propuestas de enmiendas a la Ley nº 7498/86 que reglamenta la profesión de Enfermería. Tal vez así se pueda contribuir al perfeccionamiento de dicha Ley, sugiriendo modificaciones para actualizar y consolidar la enfermería como profesión independiente y liberal. Estas propuestas surgieron de las discusiones generadas en la asignatura de Análisis Éticolegal, del Curso de Pos-Grado en Enfermería de la Universidade de São Paulo. Los documentos utilizados fueron la ley 7498/96 y el decreto n. 94406/87, que reglamentan el ejercicio de la enfermería. La metodología empleada fue el Estudio de Caso, en base a la contextualización histórico-social y ético-legal, a partir de fuentes legales escritas, bien como deliberaciones del Consejo Federal de Enfermería y demás organizaciones internacionales.
Assuntos
Humanos , Legislação de Enfermagem/ética , Prática Profissional/legislação & jurisprudência , Prática Profissional/éticaRESUMO
Este estudo teve como objeto analisar o impacto da primeira Lei de Diretrizes e Bases da Educação Nacional (LDB) em 1961, sobre escolas de enfermagem e acessibilidade ao ensino. Foram objetivos do estudo: identificar e descrever as circunstâncias históricas que envolveram a aprovação da legislação de ensino da enfermagem, anteriormente à promulgação da LDB; analisar as implicações da LDB frente ao ensino e ao funcionamento de escolas de enfermagem e a acessibilidade de candidatos a essas escolas; e, discutir a influência da LDB no processo de desenvolvimento da Enfermagem na sociedade brasileira. Trata-se de um estudo descritivo, qualitativo, exploratório, de natureza histórico-social e legal, com base em análise documental da década de 1960. A história nova, sob a ótica de Jacques Le Goff, ajuda a explicar ou recontextualizar os fatos, vinculados ao objeto do estudo por meio da triangulação de dados. As principais fontes documentais para o estudo foram a Revista Brasileira de Enfermagem e o periódico Documenta, do Conselho Federal de Educação. O Decreto n°. 20.109/31 e a Lei n°. 775/49 marcaram profundamente as estruturas do ensino e estabeleceram os primeiros currículos de enfermagem. Ao se analisar hoje o impacto da LDB, parece claro que preocupações de muitas diretoras de escolas de enfermagem no período da década de 1960 não se confirmaram de todo, como por exemplo, a acessibilidade de novas alunas aos cursos de enfermagem. Quanto às escolas de enfermagem, defato, ocorreu um decréscimo significativo delas, pois havia muitas vagas ociosas nos cursos existentes, durante, praticamente, toda a década do estudo. Quanto ao desenvolvimento da profissão como um todo à luz da LDB, pode-se destacar que houve impacto sobre a regulamentação profissional.
This study aimed to having as object to analyze the impact of the first Law for National Education Guidelines and Basis (LDB) in 1961, over schools of nursing and accessibility to education. Objectives of the study were: to identify and describe the historical circumstances which involved the approval of the nursing educations enactments prior to the promulgation of the LDB; to analyze the implications of LDB in relation to education and functioning of the nursing schools and accessibility of candidates to them; and, to discuss the LDB influence on the nursing development process in the Brazilian society. It is a descriptive, qualitative, exploratory study of historical, social and legal nature, based on documental analysis on the 1960s decade. The new history under Jacques Le Goffs perspective helps to explain and re-contextualize facts linked to the study object through triangulation of data. The main documental sources were the Revista Brasileira de Enfermagem (Brazilian Journal of Nursing) and the journal Documenta from the Brazilian Federal Education Council. The Decree 20,109 enacted in 1931 and the Law 775, in 1949, deeply marked the educational structures and established the first nursing curricula. Analyzing today the LDB impact, it seems clear that many of the nursing schools deans, at the 1960s, worries have not confirmed in all, for example, on the accessibility of new students to the nursing courses. In relation to the nursing schools, as a matter offact, it has had a significant reduction of its number, as there were many vacancies in the existent courses practically during the whole decade of this study. In relation to the profession development as a whole in the light of the LDB, an impact on the professional regulation should be highlighted.
Assuntos
Instituições AcadêmicasRESUMO
Molecular aspects of heat-shock response were investigated in monogenetic and digenetic members of the Trypanosomatidae and the data obtained compared. Trypanosoma cruzi and Crithidia fasciculata differ in the number of heat-shock proteins (HSPs) induced and in the range of supra-optimal temperature induction of these proteins. Whereas low molecular weight Hsps were induced by high temperature in Crithidia, this effect was only seen in T. cruzi after ethanol treatment. The 61 kDa peptide of T. cruzi, induced by heat, was characterized as a HSP60 family member by Western blot using a Mycobacterium polyclonal anti-HSP60 antibody. The HSP61 aa. sequence, deduced from the isolated HSP60 gene and its mRNA product were characterized. The predicted aa. sequence has shown the presence of a mitochondrial peptide leader and no large domains of aa. sequence conservation were found when compared to other known HSP60, in contrast to what is observed in HSP70. Furthermore, the HSP60 gene is apparently conserved in T. cruzi, C. fascilulata and Leishmania as suggested by genomic Southern blot analysis.