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1.
Braz. j. biol ; 82: e234413, 2022. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1249269

RESUMO

The viscera and other residues from fish processing are commonly discarded by the fishing industry. These byproducts can be a source of digestive enzymes with industrial and biotechnological potential. In this study, we aimed at the extraction, characterization, and application of acidic proteases from the stomach of Carangoides bartholomaei (Cuvier, 1833). A crude extract from the stomachs was obtained and submitted to a partial purification process by salting-out, which obtained a Purified Extract (PE) with a specific proteolytic activity of 54.0 U·mg-1. A purification of 1.9 fold and a yield of 41% were obtained. The PE presents two isoforms of acidic proteases and a maximum proteolytic activity at 45 °C and pH 2.0. The PE acidic proteolytic activity was stable in the pH range of 1.5 to 7.0 and temperature from 25 °C to 50 °C. Purified Extract kept 35% of its proteolytic activity at the presence of NaCl 15% (m/v) but was totally inhibited by pepstatin A. Purified Extract aspartic proteases presented high activity in the presence of heavy metals such as Cd2+, Hg2+, Pb2+, Al3+, and Cu2+. The utilization of PE as an enzymatic addictive in the collagen extraction from Nile tilapia scales has doubled the process yield. The results indicate the potential of these aspartic proteases for industrial and biotechnological applications.


As vísceras e outros resíduos do processamento de peixes são geralmente descartados pela indústria pesqueira. Esses resíduos podem ser uma fonte de enzimas digestivas com potencial industrial e biotecnológico. Neste estudo, objetivamos a extração, caracterização e aplicação de proteases aspárticas do estômago de Carangoides bartholomaei (Cuvier, 1833). Um extrato bruto do estômago foi obtido e submetido a um processo de purificação parcial, que obteve um Extrato Purificado (EP) com uma atividade proteolítica específica de 54,0 U·mg-1. Foi obtida uma purificação de 1,9 vezes e um rendimento de 41%. O EP apresenta duas isoformas de proteases ácidas e atividade proteolítica máxima a 45 °C e pH 2,0. A atividade proteolítica do EP foi estável na faixa de pH de 1,5 a 7,0 e temperatura de 25 °C a 50 °C. O EP manteve 35% de sua atividade proteolítica na presença de NaCl a 15% (m/v), mas foi totalmente inibida pela pepstatina A. As proteases ácidas do EP apresentaram alta atividade na presença de metais pesados como o Cd2+, Hg2+, Pb2+, Al3+ e Cu2+. A utilização de EP como aditivo enzimático na extração de colágeno a partir de escamas de tilápia do Nilo dobrou o rendimento do processo. Os resultados indicam um potencial dessas proteases para aplicações industriais e biotecnológicas.


Assuntos
Peptídeo Hidrolases , Estômago , Temperatura , Concentração de Íons de Hidrogênio
2.
Braz. j. biol ; 82: 1-7, 2022. tab, ilus, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468429

RESUMO

This work aimed to obtain aspartic proteases of industrial and biotechnological interest from the stomach of the crevalle jack fish (Caranx hippos). In order to do so, a crude extract (CE) of the stomach was obtained and subjected to a partial purification by salting-out, which resulted in the enzyme extract (EE) obtainment. EE proteases were characterized physicochemically and by means of zymogram. In addition, the effect of chemical agents on their activity was also assessed. By means of salting-out it was possible to obtain a purification of 1.6 times with a yield of 49.4%. Two acid proteases present in the EE were observed in zymogram. The optimum temperature and thermal stability for EE acidic proteases were 55 ºC and 45 °C, respectively. The optimum pH and pH stability found for these enzymes were pH 1.5 and 7.0, respectively. Total inhibition of EE acid proteolytic activity was observed in the presence of pepstatin A. dithiothreitol (DTT) and Ca2+ did not promote a significant effect on enzyme activity. In the presence of heavy metals, such as Al3+, Cd2+ and Hg2+, EE acidic proteases showed more than 70% of their enzymatic activity. The results show that it is possible to obtain, from the stomach of C. hippos, aspartic proteases with high proteolytic activity and characteristics that demonstrate potential for industrial and biotechnological applications.


Este trabalho objetivou obter proteases aspárticas de interesse industrial e biotecnológico a partir do estômago do peixe xaréu (Caranx hippos). Para isso, foi obtido um extrato bruto do estômago, o qual foi submetido a uma purificação parcial por salting-out onde se obteve o extrato enzimático (EE). As proteases do EE foram caracterizadas físico-quimicamente e através de zimograma. Além disso, o efeito de agentes químicos sobre sua atividade também foi avaliado. Através de salting-out foi possível obter uma purificação de 1,6 vezes com rendimento de 49,4%. Foram observadas duas proteases ácidas presentes no EE através de zimograma. A temperatura ótima e a estabilidade térmica para as proteases ácidas do EE foram de 55 ºC e 45 °C, respectivamente. O pH ótimo e a estabilidade ao pH encontrados para estas enzimas foram o pH 1,5 e 7,0, respectivamente. Observou-se a inibição total da atividade proteolítica ácida do EE na presença de pepstatina A. O ditiotreitol (DTT) e o Ca2+ não promoveram efeito significativo na atividade enzimática. Na presença de metais pesados, como Al3+, Cd2+ e Hg2+, o EE manteve mais de 70% de atividade enzimática do EE. Os resultados mostram que é possível obter, a partir do estômago de C. hippos, proteases aspárticas com alta atividade proteolítica e características que demonstram potencial para aplicações industriais e biotecnológicas.


Assuntos
Animais , Estômago/enzimologia , Estômago/química , Peixes , Ácido Aspártico Proteases/análise , Ácido Aspártico Proteases/economia
3.
Braz. j. biol ; 82: 1-8, 2022. tab, ilus, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468480

RESUMO

The viscera and other residues from fish processing are commonly discarded by the fishing industry. These by products can be a source of digestive enzymes with industrial and biotechnological potential. In this study, we aimed at the extraction, characterization, and application of acidic proteases from the stomach of Carangoides bartholomaei (Cuvier, 1833). A crude extract from the stomachs was obtained and submitted to a partial purification process by salting-out, which obtained a Purified Extract (PE) with a specific proteolytic activity of 54.0 U·mg-¹. A purification of 1.9 fold and a yield of 41% were obtained. The PE presents two isoforms of acidic proteases and a maximum proteolytic activity at 45 °C and pH 2.0. The PE acidic proteolytic activity was stable in the pH range of 1.5 to 7.0 and temperature from 25 °C to 50 °C. Purified Extract kept 35% of its proteolytic activity at the presence of NaCl 15% (m/v) but was totally inhibited by pepstatin A. Purified Extract aspartic proteases presented high activity in the presence of heavy metals such as Cd2+, Hg2+, Pb2+, Al3+, and Cu2+. The utilization of PE as an enzymatic addictive in the collagen extraction from Nile tilapia scales has doubled the process yield. The results indicate the potential of these aspartic proteases for industrial and biotechnological applications.


As vísceras e outros resíduos do processamento de peixes são geralmente descartados pela indústria pesqueira. Esses resíduos podem ser uma fonte de enzimas digestivas com potencial industrial e biotecnológico. Neste estudo, objetivamos a extração, caracterização e aplicação de proteases aspárticas do estômago de Carangoides bartholomaei (Cuvier, 1833). Um extrato bruto do estômago foi obtido e submetido a um processo de purificação parcial, que obteve um Extrato Purificado (EP) com uma atividade proteolítica específica de 54,0 U·mg-¹. Foi obtida uma purificação de 1,9 vezes e um rendimento de 41%. O EP apresenta duas isoformas de proteases ácidas e atividade proteolítica máxima a 45 °C e pH 2,0. A atividade proteolítica do EP foi estável na faixa de pH de 1,5 a 7,0 e temperatura de 25 °C a 50 °C. O EP manteve 35% de sua atividade proteolítica na presença de NaCl a 15% (m/v), mas foi totalmente inibida pela pepstatina A. As proteases ácidas do EP apresentaram alta atividade na presença de metais pesados como o Cd2+, Hg2+, Pb2+, Al3+ e Cu2+. A utilização de EP como aditivo enzimático na extração de colágeno a partir de escamas de tilápia do Nilo dobrou o rendimento do processo. Os resultados indicam um potencial dessas proteases para aplicações industriais e biotecnológicas.


Assuntos
Animais , Colágeno/análise , Estômago , Pepsina A/análise , Perciformes , Vísceras/enzimologia , Ácido Aspártico Proteases/análise
4.
Braz. j. biol ; 822022.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1468616

RESUMO

Abstract This work aimed to obtain aspartic proteases of industrial and biotechnological interest from the stomach of the crevalle jack fish (Caranx hippos). In order to do so, a crude extract (CE) of the stomach was obtained and subjected to a partial purification by salting-out, which resulted in the enzyme extract (EE) obtainment. EE proteases were characterized physicochemically and by means of zymogram. In addition, the effect of chemical agents on their activity was also assessed. By means of salting-out it was possible to obtain a purification of 1.6 times with a yield of 49.4%. Two acid proteases present in the EE were observed in zymogram. The optimum temperature and thermal stability for EE acidic proteases were 55 ºC and 45 °C, respectively. The optimum pH and pH stability found for these enzymes were pH 1.5 and 7.0, respectively. Total inhibition of EE acid proteolytic activity was observed in the presence of pepstatin A. dithiothreitol (DTT) and Ca2+ did not promote a significant effect on enzyme activity. In the presence of heavy metals, such as Al3+, Cd2+ and Hg2+, EE acidic proteases showed more than 70% of their enzymatic activity. The results show that it is possible to obtain, from the stomach of C. hippos, aspartic proteases with high proteolytic activity and characteristics that demonstrate potential for industrial and biotechnological applications.


Resumo Este trabalho objetivou obter proteases aspárticas de interesse industrial e biotecnológico a partir do estômago do peixe xaréu (Caranx hippos). Para isso, foi obtido um extrato bruto do estômago, o qual foi submetido a uma purificação parcial por salting-out onde se obteve o extrato enzimático (EE). As proteases do EE foram caracterizadas físico-quimicamente e através de zimograma. Além disso, o efeito de agentes químicos sobre sua atividade também foi avaliado. Através de salting-out foi possível obter uma purificação de 1,6 vezes com rendimento de 49,4%. Foram observadas duas proteases ácidas presentes no EE através de zimograma. A temperatura ótima e a estabilidade térmica para as proteases ácidas do EE foram de 55 ºC e 45 °C, respectivamente. O pH ótimo e a estabilidade ao pH encontrados para estas enzimas foram o pH 1,5 e 7,0, respectivamente. Observou-se a inibição total da atividade proteolítica ácida do EE na presença de pepstatina A. O ditiotreitol (DTT) e o Ca2+ não promoveram efeito significativo na atividade enzimática. Na presença de metais pesados, como Al3+, Cd2+ e Hg2+, o EE manteve mais de 70% de atividade enzimática do EE. Os resultados mostram que é possível obter, a partir do estômago de C. hippos, proteases aspárticas com alta atividade proteolítica e características que demonstram potencial para aplicações industriais e biotecnológicas.

5.
Braz. j. biol ; 822022.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1468667

RESUMO

Abstract The viscera and other residues from fish processing are commonly discarded by the fishing industry. These by-products can be a source of digestive enzymes with industrial and biotechnological potential. In this study, we aimed at the extraction, characterization, and application of acidic proteases from the stomach of Carangoides bartholomaei (Cuvier, 1833). A crude extract from the stomachs was obtained and submitted to a partial purification process by salting-out, which obtained a Purified Extract (PE) with a specific proteolytic activity of 54.0 Umg-1. A purification of 1.9 fold and a yield of 41% were obtained. The PE presents two isoforms of acidic proteases and a maximum proteolytic activity at 45 °C and pH 2.0. The PE acidic proteolytic activity was stable in the pH range of 1.5 to 7.0 and temperature from 25 °C to 50 °C. Purified Extract kept 35% of its proteolytic activity at the presence of NaCl 15% (m/v) but was totally inhibited by pepstatin A. Purified Extract aspartic proteases presented high activity in the presence of heavy metals such as Cd2+, Hg2+, Pb2+, Al3+, and Cu2+. The utilization of PE as an enzymatic addictive in the collagen extraction from Nile tilapia scales has doubled the process yield. The results indicate the potential of these aspartic proteases for industrial and biotechnological applications.


Resumo As vísceras e outros resíduos do processamento de peixes são geralmente descartados pela indústria pesqueira. Esses resíduos podem ser uma fonte de enzimas digestivas com potencial industrial e biotecnológico. Neste estudo, objetivamos a extração, caracterização e aplicação de proteases aspárticas do estômago de Carangoides bartholomaei (Cuvier, 1833). Um extrato bruto do estômago foi obtido e submetido a um processo de purificação parcial, que obteve um Extrato Purificado (EP) com uma atividade proteolítica específica de 54,0 Umg-1. Foi obtida uma purificação de 1,9 vezes e um rendimento de 41%. O EP apresenta duas isoformas de proteases ácidas e atividade proteolítica máxima a 45 °C e pH 2,0. A atividade proteolítica do EP foi estável na faixa de pH de 1,5 a 7,0 e temperatura de 25 °C a 50 °C. O EP manteve 35% de sua atividade proteolítica na presença de NaCl a 15% (m/v), mas foi totalmente inibida pela pepstatina A. As proteases ácidas do EP apresentaram alta atividade na presença de metais pesados como o Cd2+, Hg2+, Pb2+, Al3+ e Cu2+. A utilização de EP como aditivo enzimático na extração de colágeno a partir de escamas de tilápia do Nilo dobrou o rendimento do processo. Os resultados indicam um potencial dessas proteases para aplicações industriais e biotecnológicas

6.
Braz. j. biol ; 82: e234500, 2022. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1153464

RESUMO

This work aimed to obtain aspartic proteases of industrial and biotechnological interest from the stomach of the crevalle jack fish (Caranx hippos). In order to do so, a crude extract (CE) of the stomach was obtained and subjected to a partial purification by salting-out, which resulted in the enzyme extract (EE) obtainment. EE proteases were characterized physicochemically and by means of zymogram. In addition, the effect of chemical agents on their activity was also assessed. By means of salting-out it was possible to obtain a purification of 1.6 times with a yield of 49.4%. Two acid proteases present in the EE were observed in zymogram. The optimum temperature and thermal stability for EE acidic proteases were 55 ºC and 45 °C, respectively. The optimum pH and pH stability found for these enzymes were pH 1.5 and 7.0, respectively. Total inhibition of EE acid proteolytic activity was observed in the presence of pepstatin A. dithiothreitol (DTT) and Ca2+ did not promote a significant effect on enzyme activity. In the presence of heavy metals, such as Al3+, Cd2+ and Hg2+, EE acidic proteases showed more than 70% of their enzymatic activity. The results show that it is possible to obtain, from the stomach of C. hippos, aspartic proteases with high proteolytic activity and characteristics that demonstrate potential for industrial and biotechnological applications.


Este trabalho objetivou obter proteases aspárticas de interesse industrial e biotecnológico a partir do estômago do peixe xaréu (Caranx hippos). Para isso, foi obtido um extrato bruto do estômago, o qual foi submetido a uma purificação parcial por salting-out onde se obteve o extrato enzimático (EE). As proteases do EE foram caracterizadas físico-quimicamente e através de zimograma. Além disso, o efeito de agentes químicos sobre sua atividade também foi avaliado. Através de salting-out foi possível obter uma purificação de 1,6 vezes com rendimento de 49,4%. Foram observadas duas proteases ácidas presentes no EE através de zimograma. A temperatura ótima e a estabilidade térmica para as proteases ácidas do EE foram de 55 ºC e 45 °C, respectivamente. O pH ótimo e a estabilidade ao pH encontrados para estas enzimas foram o pH 1,5 e 7,0, respectivamente. Observou-se a inibição total da atividade proteolítica ácida do EE na presença de pepstatina A. O ditiotreitol (DTT) e o Ca2+ não promoveram efeito significativo na atividade enzimática. Na presença de metais pesados, como Al3+, Cd2+ e Hg2+, o EE manteve mais de 70% de atividade enzimática do EE. Os resultados mostram que é possível obter, a partir do estômago de C. hippos, proteases aspárticas com alta atividade proteolítica e características que demonstram potencial para aplicações industriais e biotecnológicas.


Assuntos
Animais , Peptídeo Hidrolases , Peixes/fisiologia , Temperatura , Concentração de Íons de Hidrogênio
7.
Braz J Biol ; 82: e234413, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34105658

RESUMO

The viscera and other residues from fish processing are commonly discarded by the fishing industry. These by-products can be a source of digestive enzymes with industrial and biotechnological potential. In this study, we aimed at the extraction, characterization, and application of acidic proteases from the stomach of Carangoides bartholomaei (Cuvier, 1833). A crude extract from the stomachs was obtained and submitted to a partial purification process by salting-out, which obtained a Purified Extract (PE) with a specific proteolytic activity of 54.0 U⋅mg-1. A purification of 1.9 fold and a yield of 41% were obtained. The PE presents two isoforms of acidic proteases and a maximum proteolytic activity at 45 °C and pH 2.0. The PE acidic proteolytic activity was stable in the pH range of 1.5 to 7.0 and temperature from 25 °C to 50 °C. Purified Extract kept 35% of its proteolytic activity at the presence of NaCl 15% (m/v) but was totally inhibited by pepstatin A. Purified Extract aspartic proteases presented high activity in the presence of heavy metals such as Cd2+, Hg2+, Pb2+, Al3+, and Cu2+. The utilization of PE as an enzymatic addictive in the collagen extraction from Nile tilapia scales has doubled the process yield. The results indicate the potential of these aspartic proteases for industrial and biotechnological applications.


Assuntos
Peptídeo Hidrolases , Estômago , Concentração de Íons de Hidrogênio , Temperatura
8.
Braz J Biol ; 82: e234500, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33787732

RESUMO

This work aimed to obtain aspartic proteases of industrial and biotechnological interest from the stomach of the crevalle jack fish (Caranx hippos). In order to do so, a crude extract (CE) of the stomach was obtained and subjected to a partial purification by salting-out, which resulted in the enzyme extract (EE) obtainment. EE proteases were characterized physicochemically and by means of zymogram. In addition, the effect of chemical agents on their activity was also assessed. By means of salting-out it was possible to obtain a purification of 1.6 times with a yield of 49.4%. Two acid proteases present in the EE were observed in zymogram. The optimum temperature and thermal stability for EE acidic proteases were 55 ºC and 45 °C, respectively. The optimum pH and pH stability found for these enzymes were pH 1.5 and 7.0, respectively. Total inhibition of EE acid proteolytic activity was observed in the presence of pepstatin A. dithiothreitol (DTT) and Ca2+ did not promote a significant effect on enzyme activity. In the presence of heavy metals, such as Al3+, Cd2+ and Hg2+, EE acidic proteases showed more than 70% of their enzymatic activity. The results show that it is possible to obtain, from the stomach of C. hippos, aspartic proteases with high proteolytic activity and characteristics that demonstrate potential for industrial and biotechnological applications.


Assuntos
Peptídeo Hidrolases , Animais , Concentração de Íons de Hidrogênio , Temperatura
10.
Nat Commun ; 11(1): 5978, 2020 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-33293507

RESUMO

Many global environmental agendas, including halting biodiversity loss, reversing land degradation, and limiting climate change, depend upon retaining forests with high ecological integrity, yet the scale and degree of forest modification remain poorly quantified and mapped. By integrating data on observed and inferred human pressures and an index of lost connectivity, we generate a globally consistent, continuous index of forest condition as determined by the degree of anthropogenic modification. Globally, only 17.4 million km2 of forest (40.5%) has high landscape-level integrity (mostly found in Canada, Russia, the Amazon, Central Africa, and New Guinea) and only 27% of this area is found in nationally designated protected areas. Of the forest inside protected areas, only 56% has high landscape-level integrity. Ambitious policies that prioritize the retention of forest integrity, especially in the most intact areas, are now urgently needed alongside current efforts aimed at halting deforestation and restoring the integrity of forests globally.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/estatística & dados numéricos , Política Ambiental , Florestas , África Central , Canadá , Mudança Climática , Conservação dos Recursos Naturais/legislação & jurisprudência , Nova Guiné , Federação Russa
11.
Mater Today Bio ; 8: 100083, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33294837

RESUMO

The fast and non-invasive detection of odors and volatile organic compounds (VOCs) by gas sensors and electronic noses is a growing field of interest, mostly due to a large scope of potential applications. Additional drivers for the expansion of the field include the development of alternative and sustainable sensing materials. The discovery that isolated cross-linked polymeric structures of suberin spontaneously self-assemble as a film inspired us to develop new sensing composite materials consisting of suberin and a liquid crystal (LC). Due to their stimuli-responsive and optically active nature, liquid crystals are interesting probes in gas sensing. Herein, we report the isolation and the chemical characterization of two suberin types (from cork and from potato peels) resorting to analyses of gas chromatography-mass spectrometry (GC-MS), solution nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS). The collected data highlighted their compositional and structural differences. Cork suberin showed a higher proportion of longer aliphatic constituents and is more esterified than potato suberin. Accordingly, when casted it formed films with larger surface irregularities and a higher C/O ratio. When either type of suberin was combined with the liquid crystal 5CB, the ensuing hybrid materials showed distinctive morphological and sensing properties towards a set of 12 VOCs (comprising heptane, hexane, chloroform, toluene, dichlormethane, diethylether, ethyl acetate, acetonitrile, acetone, ethanol, methanol, and acetic acid). The optical responses generated by the materials are reversible and reproducible, showing stability for 3 weeks. The individual VOC-sensing responses of the two hybrid materials are discussed taking as basis the chemistry of each suberin type. A support vector machines (SVM) algorithm based on the features of the optical responses was implemented to assess the VOC identification ability of the materials, revealing that the two distinct suberin-based sensors complement each other, since they selectively identify distinct VOCs or VOC groups. It is expected that such new environmentally-friendly gas sensing materials derived from natural diversity can be combined in arrays to enlarge selectivity and sensing capacity.

12.
J Intellect Disabil Res ; 62(4): 292-302, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29349826

RESUMO

BACKGROUND: Different domain-specific and domain-general cognitive precursors play a key role in the development of mathematical abilities. The contribution of these domains to mathematical ability changes during development. Primary school-aged children who show mathematical difficulties form a heterogeneous group, but it is not clear whether this also holds for preschool low achievers (LAs) and how domain-specific and domain-general abilities contribute to mathematical difficulties at a young age. The aim of this study was to explore the cognitive characteristics of a sample of preschool LAs and identify sub-types of LAs. METHODS: 81 children were identified as LAs from 283 preschoolers aged 3 to 5 years old and were assessed on a number of domain-general and domain-specific tasks. RESULTS: Cluster analysis revealed four subgroups of LAs in mathematics: (1) a weak processing sub-type; (2) a general mathematical LAs sub-type; (3) a mixed abilities sub-type; and (4) a visuo-spatial deficit sub-type. Whilst two of the groups showed specific domain-general difficulties, none showed only domain-specific difficulties. CONCLUSIONS: Current findings suggest that preschool LAs constitute a heterogeneous group and stress the importance of domain-general factors for the development of mathematical abilities during the preschool years.


Assuntos
Logro , Aptidão/fisiologia , Desenvolvimento Infantil/fisiologia , Matemática , Memória de Curto Prazo/fisiologia , Pré-Escolar , Análise por Conglomerados , Feminino , Humanos , Masculino
13.
Braz J Med Biol Res ; 36(12): 1605-12, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14666244

RESUMO

We present a critical analysis of the generalized use of the "impact factor". By means of the Kruskal-Wallis test, it was shown that it is not possible to compare distinct disciplines using the impact factor without adjustments. After assigning the median journal the value of one (1.000), the impact factor value for each journal was calculated by the rule of three. The adjusted values were homogeneous, thus permitting comparison among distinct disciplines.


Assuntos
Bibliometria , Estudos de Avaliação como Assunto , Publicações Periódicas como Assunto/estatística & dados numéricos , Editoração/estatística & dados numéricos , Especialização , Estatísticas não Paramétricas
14.
Braz. j. med. biol. res ; 36(12): 1605-1612, Dec. 2003. tab
Artigo em Inglês | LILACS | ID: lil-350470

RESUMO

We present a critical analysis of the generalized use of the "impact factor". By means of the Kruskal-Wallis test, it was shown that it is not possible to compare distinct disciplines using the impact factor without adjustments. After assigning the median journal the value of one (1.000), the impact factor value for each journal was calculated by the rule of three. The adjusted values were homogeneous, thus permitting comparison among distinct disciplines.


Assuntos
Bibliometria , Estudo de Avaliação , Publicação Periódica , Editoração , Especialização , Estatísticas não Paramétricas
15.
Mem Inst Oswaldo Cruz ; 95(1): 39-41, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10656702

RESUMO

A new species of a cucullanid nematode is described, illustrated and compared with Cucullanus brevispiculus Moravec, Kohn & Fernandes, 1993 and C. rhamphichthydis Moravec, Kohn & Fernandes, 1997, two species previously reported as parasitizing freshwater fish in South America. The new species is characterized mainly by markedly short spicules, deirids and excretory pore situated posterior to the oesophago-intestinal junction, presence of strongly sclerotized plates in the oesophastome and oesophagus divided into two distinct portions.


Assuntos
Peixes/parasitologia , Nematoides/anatomia & histologia , Animais , Brasil , Feminino , Água Doce , Masculino
16.
Vet Parasitol ; 86(1): 15-21, 1999 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-10489198

RESUMO

Thirty six horses from nine Brazilian states (Goiás, Minas Gerais, Pará, Maranhão, Piauí, Paraíba, Pernambuco, Rio Grande do Norte, and Ceará) were examined for infections by small strongyles. The following species were identified: Cylicocyclus nassatus, C. insigne, C. brevicapsulatus, C. leptostomum, C. radiatus, C. ultrajectinus, C. ashworthi, Cylicostephanus goldi, C. calicatus, C. minutus, C. longibursatus, Petrovinema poculatum, Coronocyclus coronatus, C. labiatus, C. labratus, Cyathostomum catinatum, C. pateratum, C. alveatum, Parapoteriostomum euproctus, Cylicodontophorus bicoronatus, Poteriostomum ratzii, P. imparidentatum and Gyalocephalus capitatus. The most prevalent were C. longibursatus (100%), C. nassatus (97.22%) and C. catinatum (94.44%). They were also the most abundant species, comprising 31.84, 23.71 and 14.14%, respectively, of the Cyathostominae parasites found. Infections were found to include 2-17 species in a single horse, with variable associations.


Assuntos
Infecções Equinas por Strongyloidea/epidemiologia , Strongyloidea/classificação , Animais , Brasil/epidemiologia , Feminino , Cavalos , Intestino Grosso/parasitologia , Masculino , Prevalência , Infecções Equinas por Strongyloidea/parasitologia , Strongyloidea/isolamento & purificação
18.
J Wildl Dis ; 35(2): 371-4, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10231765

RESUMO

Helminths were collected from 22 specimens of the white-bellied opossum (Didelphis albiventris) captured in the region of Pampulha (Belo Horizonte, Brazil), from May 1985 to March 1995. Ten species of helminths were collected; these included Rhopalias coronatus, Brachylaema migrans, Aspidodera raillieti, Cruzia tentaculata, Turgida turgida, Gongylonema sp., Viannaia hamata, Travassostrongylus orloffi, Trichuris didelphis and Capillaria sp.


Assuntos
Helmintíase Animal/parasitologia , Helmintos/classificação , Gambás/parasitologia , Animais , Brasil/epidemiologia , Feminino , Helmintíase Animal/epidemiologia , Helmintos/crescimento & desenvolvimento , Masculino , Nematoides/classificação , Nematoides/crescimento & desenvolvimento , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Infecções por Nematoides/veterinária , Trematódeos/classificação , Trematódeos/crescimento & desenvolvimento , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/veterinária
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