RESUMO
The technique of terrestrial sampling of boll weevil (BW) populations is expensive and inefficient over large areas, but may be cheaper and more efficient without involving the manipulation of cotton squares. The aim of this study was to develop a technique to sampling cotton squares based on the observation of opened and/or yellowing bracts to determine the need and efficacy of chemical control of BW in cotton crops. The first experiment aimed to estimate the ratio between the number of cotton squares with opened and/or yellowed bracts and that of squares with BW oviposition punctures. The second experiment, aimed to determine the efficacy of chemical control for BW by sampling cotton squares with opened and/or yellowed bracts. The ratio between the number of opened and/or yellowed bracts and the number of cotton squares with oviposition punctures was 2:1. The level and efficiency of chemical control of BW, based on the percentage and sampling of cotton plants with opened and/or yellowed bracts, was 5% and did not differ from the one based on the observation of cotton plants with 10% cotton squares with oviposition punctures by BW females. The control level based on sampling cotton plants with open and/or yellowing bracts was 5%. The efficiency of chemical insecticides using this economic threshold against the BW did not differ from that based on sampling cotton plants with 10% of cotton squares with oviposition punctures by BW females. This indicates that the chemical control of cotton boll weevil can be carried out based on cotton squares with open and/or yellowed bracts.
Assuntos
Gossypium , Controle de Insetos , Oviposição , Gorgulhos , Gorgulhos/fisiologia , Gossypium/parasitologia , Animais , Oviposição/fisiologia , Feminino , Controle de Insetos/métodos , InseticidasRESUMO
Talcum powder is recognized as the leading drug for pleurodesis, a treatment of choice for malignant pleural effusions. Recently, it was shown that hydrogel foam delivery systems significantly enhanced the number of adhesions between the chest wall and the lung in a New Zealand rabbit model due to the sol-gel transition. However, many questions still remain regarding the cause of improved efficacy, such as: (1) Would only hydrogel foams improve the efficacy of talc pleurodesis? (2) Is it possible to achieve the same efficacy of hydrogels using non-hydrogel foams? 3) What are the physicochemical properties that can be correlated to the efficacy of talc pleurodesis? In this study, we use non-hydrogel foam formulations to determine the efficacy of pleurodesis. Foam stability and rheology of the formulations were correlated to adhesion formation. The results clearly suggest a correlation of pleurodesis efficacy to the viscosity and modulus of the foam delivery system.
Assuntos
Hidrogéis/química , Pleurodese/métodos , Talco/administração & dosagem , Animais , Química Farmacêutica , Estabilidade de Medicamentos , Coelhos , Reologia , Talco/uso terapêuticoRESUMO
The number of domestic animals living with human beings is rapidly increasing in parallel with an enhanced risk of transmission of their parasites and the pathogens they might carry. The aim of this study was to assess the occurrence of hematophagous arthropods infesting domestic animals from Northeastern Brazil and to remark the implications of their occurrence on the epidemiology and control of selected veterinary and human diseases. From January 2017 to April 2019, ectoparasites infesting domestic cats, dogs and horses were collected for their respective hosts and identified. Overall, ectoparasites were sampled from 86 domestic animals, living in different anthropic settings. A total of 401 specimens (344 ticks and 57 fleas) were collected from different hosts [i.e., 10 (2.49%), 96 (23.94%) and 295 (73.57%) from cats, dogs and horses, respectively]. Two flea (i.e., Ctenocephalides canis and Ctenocephalides felis) and 5 tick species (i.e., Amblyomma ovale, Amblyomma sculptum, Dermacentor nitens, Rhipicephalus microplus and Rhipicephalus sanguineus sensu lato) were identified. This study provides data on the ectoparasite fauna infesting domestic animals from Northeastern Brazil. The diagnosis and treatment of these parasites should not be underestimated, considering the role that hematophagous arthropods display as vectors of pathogens of medical and veterinary concern.(AU)
O número de animais domésticos infestados por ectoparasitos vivendo em estreito contato com seres humanos está aumentando, elevando o risco de infecção pelos patógenos transmitidos por vetores. Objetivou-se neste estudo avaliar a ocorrência de ectoparasitos infestando animais do nordeste do Brasil e discutir as implicações desse parasitismo na epidemiologia e no controle de doenças de importância médico-veterinária. De janeiro de 2017 a abril de 2019, artrópodes foram coletados de gatos, cães e cavalos, e identificados morfologicamente. Ectoparasitos foram removidos de 86 animais infestados provenientes de áreas urbanas e rurais. Foram identificados 401 espécimes (344 carrapatos e 57 pulgas) coletados de diferentes hospedeiros (10 (2,49%), 96 (23,94%) e 295 (73,57%) de gatos, cães e cavalos, respectivamente. Duas espécies de pulgas (Ctenocephalides canis e Ctenocephalides felis) e cinco espécies de carrapatos (Amblyomma ovale, Amblyomma sculptum, Dermacentornitens, Rhipicephalus microplus e Rhipicephalus sanguineus sensu lato) foram identificadas. Este estudo fornece informações sobre a ectofauna de animais domésticos do nordeste do Brasil. Portanto, o diagnóstico e o tratamento desses parasitos não devem ser subestimados, considerando que os artrópodes aqui relatados podem veicular patógenos de importância médico-veterinária.(AU)
Assuntos
Humanos , Animais , Gatos , Cães , Carrapatos , Ectoparasitoses/epidemiologia , Sifonápteros , Cavalos/parasitologia , Brasil , Zoonoses/epidemiologia , Rhipicephalus , Ctenocephalides , Saúde Única , AmblyommaRESUMO
Radioactive ^{27}Mg (t_{1/2}=9.5 min) was implanted into GaN of different doping types at CERN's ISOLDE facility and its lattice site determined via ß^{-} emission channeling. Following implantations between room temperature and 800 °C, the majority of ^{27}Mg occupies the substitutional Ga sites; however, below 350 °C significant fractions were also found on interstitial positions â¼0.6 Å from ideal octahedral sites. The interstitial fraction of Mg was correlated with the GaN doping character, being highest (up to 31%) in samples doped p type with 2×10^{19} cm^{-3} stable Mg during epilayer growth, and lowest in Si-doped n-GaN, thus giving direct evidence for the amphoteric character of Mg. Implanting above 350 °C converts interstitial ^{27}Mg to substitutional Ga sites, which allows estimating the activation energy for migration of interstitial Mg as between 1.3 and 2.0 eV.
RESUMO
A detailed quantitative analysis of the specific heat in the 0.5- to 200-K temperature range for almost dry L-cysteine and its dimer, L-cystine, amino acids is presented. We report the occurrence of a sharp first-order transition at â¼76 K for L-cysteine associated with the thiol group ordering which was successfully modeled with the two-dimensional Ising model. We demonstrated that quantum rotors, two-level systems (TLS), Einstein oscillators, and acoustic phonons (the Debye model) are essential ingredients to correctly describe the overall experimental data. Our analysis pointed out the absence of the TLS contribution to the low temperature specific heat of L-cysteine. This result was similar to that found in other noncrystalline amorphous materials, e.g., amorphous silicon, low density amorphous water, and ultrastable glasses. L-cystine presented an unusual nonlinear acoustic dispersion relation ω(q)=vq0.95 and a Maxwell-Boltzmann-type distribution of tunneling barriers. The presence of Einstein oscillators with ΘEâ¼70 K was common in both systems and adequately modeled the boson peak contributions.
Assuntos
Cisteína/química , Cistina/química , Temperatura Alta , Dimerização , Transição de Fase , Teoria QuânticaRESUMO
Some physical properties of hydrated biomolecules, e.g., the occurrence of a boson peak, have been recognized to resemble those of glassy states. The present work shows that quantum fluctuations play a fundamental role in describing the glassy state of biomolecules, particularly at lower hydration levels. There is a linear relationship between the quantumness and the slope of the temperature dependence of the boson peak frequency, which is used to classify the extent of quantum contributions to the glassy state of glasses in general. Lastly, we demonstrate that the boson peak two-band spectral structure that is observed in some cases can be directly linked to the anisotropy of the elastic properties of the material. The amino acid L-cysteine is studied in detail. The findings are compared with previously reported data for other macromolecules.
Assuntos
Biopolímeros/química , Cisteína/química , Interações de Partículas Elementares , Modelos Químicos , Modelos Estatísticos , Teoria Quântica , Simulação por Computador , Transição de Fase , Temperatura , VibraçãoRESUMO
This in vitro study aimed to quantify water loss at histological points in ground sections of normal enamel during air drying at room temperature (25°C) and relative humidity of 50%. From each of 10 ground sections of erupted permanent human normal enamel, three histological points (n = 30) located at 100, 300 and 500 µm from enamel surface and along a transversal following prisms paths were characterized regarding the mineral, organic and water volumes. Water loss during air drying was from 0 to 48 h. Drying occurred with both falling and constant-drying rates, and drying stabilization times (Teq ) ranged from 0.5 to 11 h with a mean 0.26 (±0.12)% weight loss. In some samples (n = 5; 15 points), Teq increased as a function of the distance from the enamel surface, and drying occurred at an apparent diffusion rate of 3.47 × 10â»8 cm² s⻹. Our data provide evidence of air drying resulting in air replacing enamel's loosely bound water in prisms sheaths following a unidirectional water diffusion rate of 3.47 × 10â»8 cm² s⻹ (from the original enamel surface inward), not necessarily resulting in water evaporating directly into air, with important implications for transport processes and optical and mechanical properties.
Assuntos
Esmalte Dentário/química , Dessecação , Água/análise , Ar , Humanos , Umidade , Dente Molar/química , TemperaturaRESUMO
Two special dynamical transitions of universal character have recently been observed in macromolecules (lysozyme, myoglobin, bacteriorhodopsin, DNA and RNA) at T* ~100-150 K and T(D) ~180-220 K. The underlying mechanisms governing these transitions have been the subject of debate. In the present work, a survey is reported on the temperature dependence of structural, vibrational and thermodynamical properties of a nearly anhydrous amino acid (orthorhombic polymorph of the amino acid l-cysteine at a hydration level of 3.5%). The temperature dependence of x-ray powder diffraction patterns, Raman spectra and specific heat revealed these two transitions at T* = 70 K and T(D) = 230 K for this sample. The data were analyzed considering amino acid-amino acid, amino acid-water, water-water phonon-phonon interactions and molecular rotor activation. Our results indicated that the two referred temperatures define the triggering of very simple and particular events that govern all the interactions of the biomolecular: activation of CH(2) rigid rotors (T < T* ), phonon-phonon interactions between specific amino acid and water dimer vibrational modes (T* < T < T(D)), and water rotational barriers surpassing (T > T(D)).
Assuntos
Cisteína/química , Transição de Fase , Modelos Moleculares , Conformação Molecular , Compostos de Sulfidrila/química , Temperatura , Termodinâmica , VibraçãoRESUMO
Few studies have reported the molecular epidemiological characterization of HIV-1 in the Northern region of Brazil. The present study reports the molecular and epidemiological characterization of 31 HIV-1 isolates from blood donors from the State of Amazonas who donated blood between April 2006 and March 2007. Serum/plasma samples from all donors were screened for HIV antibodies by ELISA and the results confirmed by Western blot analysis. Genomic DNA was extracted from the buffy coat using the Super Quik-Gene-DNA Isolation kit. Nested PCR was performed on the env, gag, and pol regions of HIV-1 using the Gene Amp PCR System 9700. Sequencing reactions were performed using the inner PCR primers and the DYEnamic™ ET Dye Terminator Kit, and phylogenetic analysis was performed using the gag, pol, and env gene sequences. We collected samples from 31 blood donors who tested positive for HIV-1 in confirmatory experiments. The male:female ratio of blood donors was 3.4:1, and the mean age was 32.4 years (range: 19 to 61 years). Phylogenetic analysis showed that subtype B is the most prevalent among Northern Brazilian HIV-1-seropositive blood donors. One HIV-1 subtype C and one circulating recombinant form (CRF_BF) of HIV-1 were identified in the State of Amazonas. This is the first study showing the occurrence of a possible "homogenous" subtype C in this region of Brazil. This finding could contribute to a better characterization of the HIV-1 strains that circulate in the country.
Assuntos
Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Adulto Jovem , Doadores de Sangue , Infecções por HIV/virologia , HIV-1 , Sequência de Bases , Western Blotting , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática , Genes env/genética , Genes gag/genética , Genes pol/genética , Infecções por HIV/epidemiologia , HIV-1 , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da PolimeraseRESUMO
Few studies have reported the molecular epidemiological characterization of HIV-1 in the Northern region of Brazil. The present study reports the molecular and epidemiological characterization of 31 HIV-1 isolates from blood donors from the State of Amazonas who donated blood between April 2006 and March 2007. Serum/plasma samples from all donors were screened for HIV antibodies by ELISA and the results confirmed by Western blot analysis. Genomic DNA was extracted from the buffy coat using the Super Quik-Gene-DNA Isolation kit. Nested PCR was performed on the env, gag, and pol regions of HIV-1 using the Gene Amp PCR System 9700. Sequencing reactions were performed using the inner PCR primers and the DYEnamic™ ET Dye Terminator Kit, and phylogenetic analysis was performed using the gag, pol, and env gene sequences. We collected samples from 31 blood donors who tested positive for HIV-1 in confirmatory experiments. The male:female ratio of blood donors was 3.4:1, and the mean age was 32.4 years (range: 19 to 61 years). Phylogenetic analysis showed that subtype B is the most prevalent among Northern Brazilian HIV-1-seropositive blood donors. One HIV-1 subtype C and one circulating recombinant form (CRF_BF) of HIV-1 were identified in the State of Amazonas. This is the first study showing the occurrence of a possible "homogenous" subtype C in this region of Brazil. This finding could contribute to a better characterization of the HIV-1 strains that circulate in the country.
Assuntos
Doadores de Sangue , Infecções por HIV/virologia , HIV-1/genética , Adulto , Sequência de Bases , Western Blotting , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Genes env/genética , Genes gag/genética , Genes pol/genética , Infecções por HIV/epidemiologia , HIV-1/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Adulto JovemRESUMO
The rational of this study we intended to investigate whether the peripheral blood immunological/virological biomarkers were associated with distinct patterns of sleeping quality in patients with chronic hepatitis C-(HCV). Distinct well-established indexes/scores were used to categorize the sleeping quality of HCV patients, including the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale and Fatigue Severity Scores. Our findings demonstrated that HCV patients classified as 'good sleeper' displayed an enhanced frequency of circulating CD8(+) T cells, lower frequency of activated (CD69(+)) neutrophils and eosinophils but enhanced frequency of activated lymphocytes besides lower seric levels of IL-4/IL-8/IL-10 but higher levels of IL-12, besides lower HCV virus load and lower anti-HCV IgG levels. In contrast, HCV patients classified as 'poor sleeper' displayed enhanced levels of activated neutrophils and eosinophils but lower frequency of activated lymphocytes, higher seric levels of IL-6/TNF-α/IL-10 but lower levels of IL-12 besides higher HCV virus load and increased anti-HCV IgG levels. Positive correlation was further confirmed by the relationship between the leucocyte activation status, the cytokine levels, the HCV viral load and the anti-HCV IgG reactivity with the PSQI indexes. Analysis of cytokine signature curves demonstrated that lower frequency of IL-10 was observed in HCV patients classified as 'good sleepers', whereas enhanced frequency of IL-6 was found HCV patients classified as 'poor sleepers'. In conclusion, our data suggest that immunological biomarkers (leucocytes activation status and seric cytokines levels) are likely to be associated with sleeping quality patterns in HCV patients, suggesting their putative use for clinical monitoring purposes.
Assuntos
Hepacivirus/imunologia , Hepatite C Crônica/sangue , Transtornos do Sono-Vigília/sangue , Adulto , Idoso , Biomarcadores/sangue , Citocinas/genética , Citocinas/imunologia , Feminino , Citometria de Fluxo , Hepatite C Crônica/imunologia , Hepatite C Crônica/virologia , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , RNA Viral/química , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transtornos do Sono-Vigília/imunologia , Transtornos do Sono-Vigília/virologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T/imunologia , Adulto JovemRESUMO
AIMS/HYPOTHESIS: Diabetes increases the risk of lower extremity amputation (LEA). Although epidemiological studies report positive associations between glycaemia and LEA, the magnitude of the risk is not adequately quantified and clinical trials to date have not provided conclusive evidence about glucose lowering and LEA risk. We synthesised the available prospective epidemiological data on the association between glycaemia measured by HbA(1c) and the risk of LEA in individuals with diabetes. METHODS: We searched electronic databases and reference lists of relevant articles. We considered prospective epidemiological studies that had measured HbA(1c) level and assessed LEA as an outcome among diabetic individuals without acute foot ulcerations or previous history of amputation. Of 2,548 citations identified, we included 14 studies comprising 94,640 participants and 1,227 LEA cases. We abstracted data using standardised forms and obtained data from investigators when required. Data included characteristics of study populations, HbA(1c) assay methods, outcome and covariates. Study-specific relative risk estimates were pooled using random-effects model meta-analysis; heterogeneity was explored with meta-regression analyses. RESULTS: The overall RR for LEA was 1.26 (95% CI 1.16-1.36) for each percentage point increase in HbA(1c). There was considerable heterogeneity across studies (I (2) 76%, 67-86%; p < 0.001), which was not accounted for by recorded study characteristics. The estimated RR was 1.44 (95% CI 1.25-1.65) for type 2 diabetes and 1.18 (95% CI 1.02-1.38) for type 1 diabetes; however, the difference was not statistically significant (p = 0.09). We found no strong evidence for publication bias. CONCLUSIONS/INTERPRETATION: There is a substantial increase in risk of LEA associated with glycaemia in individuals with diabetes. In the absence of conclusive evidence from trials, this paper provides further epidemiological support for glucose-lowering as a strategy to reduce amputation in a population without acute foot ulceration or former amputation; it also provides disease modellers with estimates to assess the overall burden of hyperglycaemia.
Assuntos
Amputação Cirúrgica , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Pé Diabético/metabolismo , Hemoglobinas Glicadas/metabolismo , Humanos , RiscoRESUMO
Natural gamma radiation measurements of sand deposits were carried out in order to study the chronology of prehistoric colonization of the Brazilian coast during the Holocene. The method employs thorium, uranium and potassium as tracers of the geological provenance of Quaternary deposits, where artificial shellmounds are found. The so-called sambaquis are archaeological settlements, characteristic of fisher-gatherers, specialized in the exploitation of shellfish. Our results show a considerable positive correlation between the formation of coastal deposits, based on cross plots of eTh/eU and eTh/K, and the antiquity of its prehistoric human occupation.
Assuntos
Raios gama , Sedimentos Geológicos/química , Datação Radiométrica/métodos , Brasil , Potássio/análise , Monitoramento de Radiação/métodos , Traçadores Radioativos , Frutos do Mar/análise , Dióxido de Silício/química , Tório/análise , Urânio/análise , Resíduos/análiseRESUMO
The aim of this study was to determine the levels of Penicillium citreonigrum and citreoviridin present in rice samples from Maranhão State, Brazil, where an outbreak of beriberi was reported and 32 deaths occurred (7% of the notified cases died in 2006). The ability of P. citreonigrum to produce citreoviridin was assessed, and a total of 420 samples of 21 different kinds of rice were collected. Mycobiota isolation and identification, the ability of citreoviridin strains to produce toxin, and the natural occurrence of citreoviridin were established. Rice samples were found to have high fungal counts and showed increasing levels from 2004 to 2007 harvest years. The most frequent genus was Aspergillus followed by Penicillium and Cladosporium. Ten out of eleven strains of P. citreonigrum were able to produce citreoviridin. Three rice samples had levels of citreoviridin ranging from 12 to 96.7 ng g(-1), and two bran samples had levels of 128 and 254 ng g(-1). These samples contaminated with P. citreonigrum and citreoviridin were involved in the beriberi cases from Maranhão State. Monitoring rice for mycotoxins in areas where this substrate is the basic food is crucial to prevent outbreaks like the one reported in this study, to improve management practice, and to diminish exposure risk of humans to these harmful toxins.
Assuntos
Aurovertinas/metabolismo , Beriberi/epidemiologia , Oryza , Penicillium/metabolismo , Brasil/epidemiologia , Cromatografia Líquida de Alta Pressão , Surtos de Doenças , HumanosRESUMO
Archeological diggings in household garbage deposits from nineteenth-century Rio have uncovered an abundance of equipment used in the elimination of fecal material and phlegm. These findings formed the basis for an analysis and interpretation of the era's attitudes regarding body fluids, as adopted when the mentalities of the new 'bourgeois' segments - then undergoing a process of rise and consolidation - were impregnated by Hippocratic humoralism. The text shows how the introduction of a 'body order' was fundamental in building and keeping the social order in the nineteenth century. It likewise shows how the ideology of hygienization was one of the most important and efficacious strategies for underpinning the bourgeoisie's (victorious) project to achieve hegemony.