RESUMO
Biofilms are frequently related to invasive fungal infections and are reported to be more resistant to antifungal drugs than planktonic cells. The structural complexity of the biofilm as well as the presence of a polymeric extracellular matrix (ECM) is thought to be associated with this resistant behavior. Scanning electron microscopy (SEM) after room temperature glutaraldehyde-based fixation, have been used to study fungal biofilm structure and drug susceptibility but they usually fail to preserve the ECM and, therefore, are not an optimised methodology to understand the complexity of the fungal biofilm. Thus, in this work, we propose a comparative analysis of room-temperature and cryofixation/freeze substitution of Candida albicans biofilms for SEM observation. Our experiments showed that room-temperature fixative protocols using glutaraldehyde and osmium tetroxide prior to alcohol dehydration led to a complete extraction of the polymeric ECM of biofilms. ECM from fixative and alcohol solutions were recovered after all processing steps and these structures were characterised by biochemistry assays, transmission electron microscopy and mass spectrometry. Cryofixation techniques followed by freeze-substitution lead to a great preservation of both ECM structure and C. albicans biofilm cells, allowing the visualisation of a more reliable biofilm structure. These findings reinforce that cryofixation should be the indicated method for SEM sample preparation to study fungal biofilms as it allows the visualisation of the EMC and the exploration of the biofilm structure to its fullest, as its structural/functional role in interaction with host cells, other pathogens and for drug resistance assays.
Assuntos
Biofilmes , Candida albicans/fisiologia , Candida albicans/ultraestrutura , Microscopia Eletrônica de Varredura , Proteínas de Bactérias/metabolismo , Metabolismo dos Carboidratos , Criopreservação/métodos , Cromatografia Gasosa-Espectrometria de Massas , Microscopia Eletrônica de Varredura/métodos , TemperaturaRESUMO
The aim of this work was to determine the efficiency and feasibility of two different watermelon pest control systems on pest infestations, natural enemies, and on the productivity and sustainability of watermelon cropping. Two independent experiments were carried out during the dry season of 2011. Both experiments were carried out using a randomized block experimental design, with three treatments; weekly application of pesticide (WAP), integrated pest management (IPM), and nonpesticide application (control); and four replicates. Arthropods sampling was performed every 2 d by direct counting at five randomly selected points in each plot. Samples were taken by beating the leaves from the apical portion of the plant against a white plastic tray. Arthropods that moved along the soil surface were sampled weekly using pitfall traps. Both WAP and IPM treatments negatively affected the arthropod population. We conclude that IPM is an attractive strategy for watermelon cropping both economically and environmentally because it provides the grower with an option to lower production cost, achieves the same production, and there is less need for pesticide application when compared with the prophylactic control treatment when pesticides are applied on a weekly basis. This has not been reported for watermelon before.
Assuntos
Citrullus/crescimento & desenvolvimento , Insetos/efeitos dos fármacos , Inseticidas/farmacologia , Inseticidas/toxicidade , Controle de Pragas/métodos , Aranhas/efeitos dos fármacos , Animais , Brasil , Controle de Pragas/economiaRESUMO
Bacteria responsible for causing infections are common in hospital environments, water, soil, and food products. The infection risk is intensified by the absence of public sanitation, poor quality of life, and food scarcity. These external factors promote the dissemination of pathogens by direct contamination or biofilm formation. In this work, we identified bacterial isolates obtained from intensive care units in the southern region of Tocantins, Brazil. We compared matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques and 16S ribosomal ribonucleic acid (rRNA) molecular analysis; we also performed phenotypic characterization. Fifty-six isolates characterized using morphotinctorial tests were classified as gram-positive (80.4%; n = 45) and gram-negative (19.6%; n = 11) and were resistant to several antibiotic classes; notably, we identified the blaOXA-23 resistance gene in the ILH10 isolate. Microbial identification using MALDI-TOF MS resulted in the identification of Sphingomonas paucimobilis and Bacillus circulans. 16S rRNA sequencing revealed four isolates belonging to the genera Bacillus and Acinetobacter. The similarity was superior to 99% for Acinetobacter schindleri in the Basic Local Alignment Search Tool (BLAST), grouped in the clade superior to 90%. Several strains isolated from intensive care units (ICU) were resistant to various antibiotic classes. These techniques allowed for the identification of several microorganisms of importance in public health, enabling improvements in human infection control and proving the quality of inputs, food, and water.
Assuntos
Saúde da População , Qualidade de Vida , Humanos , RNA Ribossômico 16S , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Antibacterianos , Água , Unidades de Terapia IntensivaRESUMO
Gonadal sex differentiation in teleost fish shows greater plasticity as compared to other vertebrates, as it can be influenced by a variety of factors such as exogenous sex steroids. Exogenous estrogens, such as 17ß-estradiol (E2), can induce feminization when administered during early embryonic development. However, the mechanisms underlying the E2-induced feminization are not fully understood, especially in Neotropical species. Therefore, the aim of this study was to evaluate the effects of E2 administration on the phenotypic sex characteristics, histological assessment of the gonads, and the expression of selected genes in Astyanax altiparanae exposed to dietary E2 prior to gonadal differentiation. At 4 days post-hatch (dph), groups of 30-40 undifferentiated larvae were fed with a diet containing varying amounts of E2 for 28 days, and fish were sampled at 90 dph. Previous studies revealed that ovary formation in A. altiparanae occurred at 58 dph, whereas the first sign of testis formation was found at 73 dph. In relation to the control, E2 exposure increased the proportion of phenotypic females in 120% and 148.4% for 4 and 6 mg E2/Kg, respectively. However, histological analysis revealed that treatments did not affect gonadal sex ratio between males and females, but induced intersex (testis-ova) in the group treated with 6 mg E2/Kg food. Treatment with E2 also altered gonadal transcript levels of a selected number of genes implicated in sexual differentiation. Males overexpressed dmrt1, sox9 and amh following E2 treatment as compared to control. Females showed increased mRNA levels of dmrt1 and sox9, which might be related to the down-regulation of cyp19a1a after E2 exposure. In summary, E2 exposure during early gonadal development affected male secondary characteristics without changing the gonadal sex ratio, and altered expression of genes implicated in sexual differentiation.
Assuntos
Characidae/crescimento & desenvolvimento , Characidae/genética , Estradiol/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Gônadas/crescimento & desenvolvimento , Animais , Characidae/metabolismo , Feminino , Proteínas de Peixes/biossíntese , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Gônadas/efeitos dos fármacos , Gônadas/metabolismo , Larva/efeitos dos fármacos , Masculino , Razão de Masculinidade , América do SulRESUMO
Essentials Bovine (HBI) and porcine (HPI) heparins differ in structure and anticoagulant activity. Protamine-neutralization was evaluated on a variety of physical-chemical methods. HBI requires more protamine than HPI to fully neutralize its anticoagulant activity. Protamine preferentially removes higher-sulfated chains of HBI while HPI is evenly precipitated. SUMMARY: Background Protamine neutralization is an essential step for the safe use and inactivation of the unfractionated heparin (UFH) that is widely employed in surgical and non-surgical procedures involving extracorporeal circulation. Objective To compare protamine neutralization of different pharmaceutical-grade UFHs prepared from porcine or bovine intestine (HPI and HBI, respectively). HBI has approximately half the anticoagulant potency of HPI, mostly as consequence of its fraction enriched with N-sulfated α-glucosamine disaccharides. Methods Protamine neutralization of HPI and HBI was evaluated with in vitro, ex vivo and in vivo assays. We also performed in-depth assessments of the complexation of protamine with these distinct UFHs by using nuclear magnetic resonance and mass spectroscopy. Results HPI and HBI interact similarly with protamine on a mass/mass basis; however, HBI requires more protamine than HPI to have its anticoagulant activity fully neutralized, because of its lower potency, which entails the use of higher doses. Nuclear magnetic resonance spectra revealed that HPI precipitates homogeneously with protamine. On the other hand, the low-sulfated fraction of HBI, enriched with N-sulfated α-glucosamine, precipitates at higher concentrations of protamine than the fraction more like HPI, with a preponderance of N,6-disulfated α-glucosamine disaccharides. Finally, mass spectroscopy spectra showed that some of the different peptide components of protamine interact preferentially with the heparins, irrespective of their animal origin. Conclusion Our results have important medical implications, indicating that protamine neutralization of HBI, determined exclusively by point-of-care coagulation assessments, must fail because of its lower-sulfated fraction with reduced anticoagulant activity that could remain in the circulation after the neutralization procedure.
Assuntos
Anticoagulantes/farmacologia , Antagonistas de Heparina/farmacologia , Heparina/farmacologia , Protaminas/farmacologia , Animais , Anticoagulantes/química , Anticoagulantes/isolamento & purificação , Bioensaio , Bovinos , Precipitação Química , Cromatografia de Afinidade , Dissacarídeos/química , Relação Dose-Resposta a Droga , Heparina/química , Heparina/isolamento & purificação , Mucosa Intestinal/química , Espectrometria de Massas , Ressonância Magnética Nuclear Biomolecular , Tempo de Tromboplastina Parcial , Protaminas/química , Ratos , Especificidade da Espécie , Enxofre/análise , SuínosRESUMO
(124)I is a radionuclide used in the diagnosis of tumors. The National Health Agency requires identification and activity measurement of impurities. Using gamma spectrometry with an efficiency calibrated high-purity germanium detector, impurities (125)I and (126)I in an (1)(24)I production sample were identified. Activity ratios of (125)I and (126)I to (124)I were approximately 0.5% and 98%, respectively.
Assuntos
Contaminação de Medicamentos/prevenção & controle , Radioisótopos do Iodo/análise , Radioisótopos do Iodo/normas , Radiometria/métodos , Radiometria/normas , Espectrometria gama/normas , Brasil , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria gama/métodosRESUMO
The indication of biomaterials has increased substantially in the regenerative therapy of bone defects. However, in addition to evaluating the physicochemical properties of biomaterials, the quality of the recipient tissue is also essential for the osseointegration of implants, as abnormalities in bone metabolism, such as gonadal hormone deficiency, can influence bone healing. This study evaluated the osteoregenerative capacity of collagen membranes derived from bovine pericardium and intestinal serosa in the repair of cranial defects in ovariectomised rats. Thirty female Wistar rats were submitted to surgical creation of a 5-mm cranial bone defect. The rats were divided into a control group (not ovariectomised) and an ovariectomised group. The non-ovariectomised group was divided into three subgroups: control (G1) in which the defect was not filled with the biomaterial, and two subgroups (G2 and G3) that received the bovine pericardium- and serosa-derived collagen membranes, respectively. The ovariectomised group was divided into the same subgroups (G4, G5, and G6). The animals were sacrificed 8 weeks after surgery. The calvaria were removed for macroscopic and radiographic photodocumentation and processed for histomorphometric analysis of bone healing at the surgical site. Macroscopic, radiological, and microscopic analyses demonstrated the biocompatibility of the implanted collagen membranes, as indicated by the absence of infiltration and signs of inflammation at the surgical site. Histologically, discrete immature bone neoformation projecting from the margins of the defect was observed at the surgical site in ovariectomised groups when compared to the non-ovariectomised groups. The volume of newly formed bone was significantly higher in the non-ovariectomised groups (G1: 7.83%±1.32; G2: 21.33%±1.96; and G3: 22.83%±0.98) compared to the respective ovariectomised subgroups (G4: 3.16%±0.75; G5: 16.83%±0.98; and G6: 16.16%±0.75), thus demonstrating the deleterious effects of ovariectomy on bone homeostasis. Higher volumes of newly formed bone were observed in the groups receiving the membrane grafts (G2, G3, G5, and G6) compared to the control groups (G1 and G4). In conclusion, the bilateral ovariectomy compromises the ability to repair bone lesions grafted with osteoconductive biomaterials as in the case of collagen membranes derived from both bovine pericardium and intestinal serosa.
Assuntos
Materiais Biocompatíveis/farmacologia , Colágeno/farmacologia , Pericárdio/patologia , Crânio/patologia , Cicatrização/fisiologia , Animais , Bovinos , Modelos Animais de Doenças , Estudos de Viabilidade , Feminino , Ovariectomia , Ratos , Ratos Wistar , Transplante HeterólogoRESUMO
The aim of the present study was to assess the effects of replacing corn silage with sugarcane in the diet of lactating Saanen goats and to determine their intake and digestibility of nutrients, ingestive behavior, milk yield and composition. The experimental diets were composed of increasing levels (0, 33, 66 and 100%) of substitution in dry matter (DM). Twelve multiparous Saanen goats, with an average body weight of 45.2kg, average milk yield of 3.0kg day-1, distributed in a triple latin square experimental design (4 × 4) were used. The dry matter intake (DMI) and other nutrients were estimated through the difference between the total nutrient in the food offered and its total in the leftovers. The DMI, crude protein, neutral detergent fiber (NDF) and total digestible nutrients were not influenced, but the apparent digestibility of DM and NDF decreased. Feeding time and feeding efficiency were not influenced, the rumination and total chewing times increased, and the leisure time decreased, both linearly. Milk yield was not influenced by substitution levels, but corrected milk yield to 3.5% fat decreased. Sugar cane represents a dietary alternative for goats with medium milk yield in critical periods of forage, since it does not change the consumption of DM and milk yield, even with the apparent declining digestibility of some nutrients, influencing the ingestive behavior of the animals.(AU)
O objetivo do presente estudo foi avaliar os efeitos da substituição da silagem de milho por cana-de-açúcar na dieta de cabras Saanen em lactação e determinar a ingestão e a digestibilidade de nutrientes, o comportamento ingestivo, a produção e a composição do leite. As dietas experimentais foram compostas de níveis crescentes (0, 33, 66 e 100%) de substituição na matéria seca (MS). Doze cabras Saanen multíparas, com peso corporal médio de 45,2kg, produção média de leite de 3,0kg dia-1, foram distribuídas em delineamento experimental triplo quadrado latino (4 × 4). A ingestão de matéria seca (IMS) e de outros nutrientes foi estimada por meio da diferença entre o total de nutrientes nos alimentos oferecidos e o total nas sobras. A IMS, a proteína bruta, a fibra em detergente neutro (FDN) e os nutrientes digestíveis totais não foram influenciados, mas a digestibilidade aparente da MS e da FDN diminuiu. A produção de leite não foi influenciada pelos níveis de substituição, mas a produção de leite corrigida para 3,5% de gordura diminuiu. A cana-de-açúcar representa uma alternativa alimentar para cabras com produção média de leite em períodos críticos de forragem, pois não altera o consumo de MS e a produção de leite, mesmo diminuindo a digestibilidade aparente de alguns nutrientes e influenciando o comportamento ingestivo dos animais.(AU)
Assuntos
Animais , Feminino , Cabras/metabolismo , Fibras na Dieta/administração & dosagem , Saccharum , Ração Animal , Fenômenos Fisiológicos do Sistema Digestório , Ingestão de AlimentosRESUMO
This study reviewed the literature on Patient's Satisfaction in published articles in national and international bulletins. The concepts and dimensions of satisfaction have been identified since it is important to measure patient's opinions on satisfaction, which we consider prominent points. Once we have accomplished the analysis of several studies in this context, to serve as a basis for future research geared at measuring patient's satisfaction, comparative analysis of correlated subjects has been done, when several questionnaires on Services Evaluation and Patient's Self-Evaluation on Satisfaction were studied getting to a consensus that they could serve as subsidy for the orientation and development in this kind of research with little adaptation and improvement.
Assuntos
Pesquisa sobre Serviços de Saúde/métodos , Satisfação do Paciente , Inquéritos e Questionários/normas , Humanos , Indicadores de Qualidade em Assistência à Saúde , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Sulfated galactans are polysaccharides with heterogeneous structures that frequently show anticoagulant activity. Their anticoagulant mechanisms are complex and distinct from those observed for heparin. Sulfated galactans act through a combination of effects involving serpin-dependent and serpin-independent mechanisms. Interestingly, these polymers can also induce blood coagulation due to activation of factor XII (FXII). OBJECTIVES: The structure of a complex sulfated galactan from the red alga Acanthophora muscoides was characterized by solution nuclear magnetic resonance. This polysaccharide and another previously characterized algal sulfated galactan from Botryocladia occidentalis were each used in in vitro and in vivo anticoagulant and antithrombotic assays to understand the possible structural determinants of their functional effects. RESULTS AND CONCLUSIONS: The serpin-dependent anticoagulant effects and FXII-related procoagulant effects of the sulfated galactans decreased in parallel with the molecular size. The serpin-independent anticoagulation also correlated with the chemical structure of the sulfated galactans. The sulfated galactan from A. muscoides, which showed mostly serpin-independent anticoagulant activity and reduced activation of FXII, drastically reduced arterial thrombus formation. However, the sulfated galactans produced opposite effects on venous thrombosis; this difference appears to result from the tenuous balance between the various effects on coagulation, including serpin-dependent and serpin-independent anticoagulation and FXIIa-dependent procoagulation. This study of novel sulfated polysaccharides with distinct effects on coagulation and thrombosis helps to establish the minimal structural-function relationship required for the development of antithrombotic drugs.
Assuntos
Anticoagulantes/farmacologia , Antitrombinas/farmacologia , Galactanos/farmacologia , Serpinas/fisiologia , Sulfatos/química , Anticoagulantes/química , Antitrombinas/química , Cromatografia por Troca Iônica , Galactanos/química , Espectroscopia de Ressonância MagnéticaRESUMO
PURPOSE: Several studies have reported methodologies to calculate and correct the transit dose component of the moving radiation source for high dose rate (HDR) brachytherapy planning systems. However, most of these works employ the average source speed, which varies significantly with the measurement technique used, and does not represent a realistic speed profile, therefore, providing an inaccurate dose determination. In this work, the authors quantified the transit dose component of a HDR unit based on the measurement of the instantaneous source speed to produce more accurate dose values. METHODS: The Nucletron microSelectron-HDR Ir-192 source was characterized considering the Task Group 43 (TG-43U1) specifications. The transit dose component was considered through the calculation of the dose distribution using a Monte Carlo particle transport code, MCNP5, for each source position and correcting it by the source speed. The instantaneous source speed measurements were performed in a previous work using two optical fibers connected to a photomultiplier and an oscilloscope. Calculated doses were validated by comparing relative dose profiles with those obtained experimentally using radiochromic films. RESULTS: TG-43U1 source parameters were calculated to validate the Monte Carlo simulations. These agreed with the literature, with differences below 1% for the majority of the points. Calculated dose profiles without transit dose were also validated by comparison with ONCENTRA(®) Brachy v. 3.3 dose values, yielding differences within 1.5%. Dose profiles obtained with MCNP5 corrected using the instantaneous source speed profile showed differences near dwell positions of up to 800% in comparison to values corrected using the average source speed, but they are in good agreement with the experimental data, showing a maximum discrepancy of approximately 3% of the maximum dose. Near a dwell position the transit dose is about 22% of the dwell dose delivered by the source dwelling 1 s and reached 104.0 cGy per irradiation in a hypothetical clinical case studied in this work. CONCLUSIONS: The present work demonstrated that the transit dose correction based on average source speed fails to accurately correct the dose, indicating that the correct speed profile should be considered. The impact on total dose due to the transit dose correction near the dwell positions is significant and should be considered more carefully in treatments with high dose rate, several catheters, multiple dwell positions, small dwell times, and several fractions.
Assuntos
Braquiterapia/métodos , Radioisótopos de Irídio/uso terapêutico , Doses de Radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Dosimetria Fotográfica , Método de Monte Carlo , Dosagem Radioterapêutica , Reprodutibilidade dos TestesRESUMO
Defects associated with bone mass loss are frequently treated by autogenous bone grafting. However, synthetic biomaterials such as calcium phosphate ceramics can substitute autologous grafts as long as they are biocompatible with bone tissue. In addition, low-level laser therapy (LLLT) is used to enhance bone regeneration by stimulating the local microcirculation and increasing the synthesis of collagen by bone cells. However, bone health is fundamental for osseointegration of the graft and bone repair. In this respect, excessive tobacco consumption can compromise expected outcomes because of its deleterious effects on bone metabolism that predispose to the development of osteoporosis. The objective of this study was to evaluate the regeneration of bone defects implanted with biomaterial and stimulated by LLLT in rats submitted to passive cigarette smoking. Porous hydroxyapatite granules were implanted into critical-size defects induced experimentally in the distal epiphysis of the right femur of 20 female Wistar rats submitted to passive smoking for 8 months in a smoking box. The defect site was irradiated with a gallium-arsenide laser at an intensity of 5.0 J/cm2. The animals were divided into four groups: control (non-smoking) rates submitted (G2) or not (G1) to laser irradiation, and smoking rats submitted (G4) or not (G3) to laser irradiation. The animals were sacrificed 8 weeks after biomaterial implantation. The right femurs were removed for photodocumentation, radiographed, and processed for routine histology. The results showed good radiopacity of the implant site and of the hydroxyapatite granules. Histologically, formation of new trabecular bone was observed adjacent to the hydroxyapatite granules in G1 and G2. In G3 and G4, the granules were surrounded mainly by connective tissue. In conclusion, passive smoking compromised bone neoformation in the defects and the LLLT protocol was not adequate to stimulate local osteogenesis.
Assuntos
Substitutos Ósseos , Durapatita , Osseointegração , Poluição por Fumaça de Tabaco/efeitos adversos , Animais , Modelos Animais de Doenças , Feminino , Inalação , Terapia a Laser , Osteoporose , Ratos , Ratos WistarRESUMO
Objetivo: analisar e representar, espacialmente, a evolução da distribuição geográfica dasocorrências de Hanseníase no Maranhão entre os anos de 2013 a 2015, utilizando técnicas degeoprocessamento. Método: realizou-se análise, utilizando mapas e tabelas temáticas, com base nosregistros do Sistema de Informação de Agravos de Notificação. Resultados: foram identificados 1.879casos, somados entre 219 bairros residenciais. Para o ano de 2013, o distrito mais afetado foi oTirirical; em 2014, aumentou a prevalência nos Distritos de Bequimão e Coroadinho e em 2015, houveuma redução de prevalências nos distritos de Tirirical Cohab, Coroadinho e Itaqui Bacanga.Conclusão: apesar de algumas localidades estudadas terem apresentado uma diminuição daprevalência entre 2013 e 2014, de 2014 a 2015 houve um aumento na quantidade de casos. O estudode prevalências possibilitou essa identificação de casos, podendo ser observada a imprescindibilidadede subsidiar estratégias de controle.
Objective: to analyze and spatially represent the evolution of the geographic distribution ofoccurrences of Leprosy in Maranhão between the years 2013 to 2015 using geoprocessing techniques.Method: the analysis was performed using maps and thematic tables, based on the records of theNotifiable Diseases Information System. Results: 1.879 cases were identified, among 219 residentialdistricts. For the year 2013, the district most affected was Tirirical; in 2014, increased prevalencein the Districts of Bequimão and Coroadinho and in 2015, there was a reduction of prevalences in thedistricts of Tirirical Cohab, Coroadinho and Itaqui Bacanga. Conclusion: although some localitiesstudied showed decrease in their prevalence between 2013 and 2014; there was increase in thenumber of cases from 2014 to 2015. The prevalence study made it possible to identify cases, and itis possible to observe the necessity of subsidizing control strategies.
Assuntos
Humanos , Epidemiologia , Hanseníase , Mapeamento GeográficoRESUMO
In Brazil, scientific research is carried out mainly at universities, where professors coordinate research projects with the active participation of undergraduate and graduate students. However, there is no formal program for the teaching/learning of the scientific method. The objective of the present study was to evaluate the comprehension of the scientific method by students of health sciences who participate in scientific projects in an academic research laboratory. An observational descriptive cross-sectional study was conducted using Edgar Morin complexity as theoretical reference. In a semi-structured interview, students were asked to solve an abstract logical puzzle - TanGram. The collected data were analyzed using the hermeneutic-dialectic analysis method proposed by Minayo and discussed in terms of the theoretical reference of complexity. The students' concept of the scientific method is limited to participation in projects, stressing the execution of practical procedures as opposed to scientific thinking. The solving of the TanGram puzzle revealed that the students had difficulties in understanding questions and activities focused on subjects and their processes. Objective answers, even when dealing with personal issues, were also reflected on the students' opinions about the characteristics of a successful researcher. Students' difficulties concerning these issues may affect their scientific performance and result in poorly designed experiments. This is a preliminary study that should be extended to other centers of scientific research.
Assuntos
Biologia , Compreensão , Projetos de Pesquisa/normas , Pesquisa/educação , Estudantes de Ciências da Saúde , Adulto , Brasil , Estudos Transversais , Feminino , Humanos , Laboratórios , Masculino , UniversidadesRESUMO
RESUMO O objetivo deste estudo foi avaliar o potencial fungitóxicos dos óleos essenciais de Cymbopogon citratus, Lippia sidoides, e de seus constituintes majoritários, sobre o crescimento micelial dos fitopatógenos Rhizoctonia solani e Sclerotium rolfsii. A caracterização química do óleo de L. sidoides demonstrou a presença do carvacrol (33,27%) e o 1,8-cineol (24,41%) como seus componentes majoritários. Enquanto que o citral (77,6%) foi o constituinte majoritário do óleo essencial de C. citratus. A avaliação do potencial fungitóxico dos óleos essenciais e de seus constituintes majoritários foi realizada por meio de ensaios in vitro, avaliando a inibição do crescimento micelial dos microrganismos. Ambos os óleos essenciais inibiram totalmente o crescimento micelial de R. solani na concentração de 400 µg mL-1. O crescimento micelial de S. rolfsii foi inibido pelo óleo essencial de C. citratus na concentração de 300 µg mL-1 e pelo óleo essencial de L. sidoides na concentração de 400 µg mL-1. Em relação aos constituintes majoritários, o 1,8-cineol não apresentou efeito fungitóxico nas concentrações avaliadas. No entanto, o carvacrol e o citral foram mais efetivos que os óleos essenciais havendo ausência de crescimento micelial de R. solani e de S. rolfsii nas concentrações de 200 µg mL-1 e 225 µg mL-1, respectivamente.
ABSTRACT The objective of this study was to evaluate the fungitoxic potentials of the essential oils of Cymbopogon citratus, Lippia sidoides, and of its major constituents, on the mycelial growth of phytopathogens Rhizoctonia solani and Sclerotium rolfsii. The chemical characterization of L. sidoides oil showed the presence of carvacrol (33.27%) and of 1,8-cineole (24.41%) as its major components, whereas citral (77.6%) was the major constituent of C. citratus essential oil. The evaluation of the fungitoxic potential of the essential oils and of its major constituents was performed through in vitro assays, the microorganisms mycelial growth inhibition. Both essential oils totally inhibited the mycelial growth of R. solani at 400 µg mL-1. Regarding the major constituents, the 1,8-cineole did not show fungitoxic effect at the concentrations evaluated. However, the carvacrol and the citral were more effective than the essential oils and there was no mycelial growth of R. solani and of S. rolfsii at the concentrations of 200 µg mL-1 and 225 µg mL-1, respectively.
Assuntos
Rhizoctonia/classificação , Técnicas In Vitro/instrumentação , Óleos Voláteis/análise , Cymbopogon/classificação , Lippia/classificação , QuímicaRESUMO
INTRODUCTION: Anxiety can be considered an emotional state that does not present itself at the same intensity in all patients, and can be classified into 3 levels: mild, moderate, and severe. The patient, upon entering the waiting list for transplantation, reflects on the decision taken, which leaves him constantly anxious about the idea of possible death. OBJECTIVE: This study had the aim of evaluating the degree of anxiety observed in orthotopic liver transplantation (OLT) candidates and whether there was a correlation between anxiety and etiologic diagnosis. METHODS: This study was a prospective study where the patients underwent psychological evaluation by Beck Anxiety Inventory (BAI). The anxiety level was minimal, mild, moderate, or severe. The Model for End-Stage Liver Disease (MELD) score and etiology were recorded. RESULTS: The level of anxiety found were as follows: 55% minimal, 27% mild, 12% moderate, and 7% severe. The correlation between level of anxiety and etiologic diagnosis showed that 71% of patients with alcoholic cirrhosis and 60% of those with liver cancer showed a minimal degree of anxiety and 27% of patients with autoimmune cirrhosis had severe anxiety. CONCLUSION: We found that in patients with autoimmune hepatitis, the degree of anxiety was more pronounced. It is believed that the absence of physical symptoms is an important factor when observing anxiety in OLT candidates.
Assuntos
Ansiedade/etiologia , Hepatite Autoimune/psicologia , Falência Hepática/psicologia , Falência Hepática/cirurgia , Transplante de Fígado/psicologia , Listas de Espera , Adulto , Idoso , Ansiedade/fisiopatologia , Tomada de Decisões , Medo , Feminino , Hepatite Autoimune/cirurgia , Humanos , Cirrose Hepática Alcoólica/psicologia , Cirrose Hepática Alcoólica/cirurgia , Neoplasias Hepáticas/psicologia , Neoplasias Hepáticas/cirurgia , Masculino , Estado Civil , Pessoa de Meia-Idade , Ocupações , Estudos Prospectivos , Aposentadoria , Fatores de Risco , Estresse Psicológico/etiologia , Desemprego , Adulto JovemRESUMO
In Brazil, scientific research is carried out mainly at universities, where professors coordinate research projects with the active participation of undergraduate and graduate students. However, there is no formal program for the teaching/learning of the scientific method. The objective of the present study was to evaluate the comprehension of the scientific method by students of health sciences who participate in scientific projects in an academic research laboratory. An observational descriptive cross-sectional study was conducted using Edgar Morin complexity as theoretical reference. In a semi-structured interview, students were asked to solve an abstract logical puzzle - TanGram. The collected data were analyzed using the hermeneutic-dialectic analysis method proposed by Minayo and discussed in terms of the theoretical reference of complexity. The students’ concept of the scientific method is limited to participation in projects, stressing the execution of practical procedures as opposed to scientific thinking. The solving of the TanGram puzzle revealed that the students had difficulties in understanding questions and activities focused on subjects and their processes. Objective answers, even when dealing with personal issues, were also reflected on the students’ opinions about the characteristics of a successful researcher. Students’ difficulties concerning these issues may affect their scientific performance and result in poorly designed experiments. This is a preliminary study that should be extended to other centers of scientific research.
Assuntos
Adulto , Feminino , Humanos , Biologia , Compreensão , Projetos de Pesquisa/normas , Pesquisa/educação , Estudantes de Ciências da Saúde , Brasil , Estudos Transversais , Laboratórios , UniversidadesRESUMO
O carrapato bovino Riphicephalus microplus (Acari: Ixodidae) constitui um dos grandes problemas enfrentado pelos pecuaristas de várias partes do mundo. No Brasil este ectoparasita causa grandes prejuízos à bovinocultura devido ao processo de hematofagia e pela transmissão de agentes patogênicos nos animais hospedeiros. Diante dessa situação os produtores normalmente aplicam carrapaticidas organossintéticos de forma indiscriminada. Este método normalmente resulta em: intoxicação dos animais e dos aplicadores, resíduos de carrapaticidas nos produtos de origem animal, resistência dos carrapatos aos carrapaticidas químicos e poluição ambiental. Uma alternativa para diminuir esses problemas é uso de biocarrapaticidas de origem botânica. Os pesticidas botânicos são produtos naturais derivados do metabolismo secundário das plantas. Esse metabolismo produz uma grande diversidade de compostos com ação carrapaticida que podem ser explorados através do uso de óleos essenciais ou como modelo para síntese de pesticidas sintéticos. A necessidade de métodos mais seguros, menos agressivos ao homem e ao meio ambiente, tem estimulado a busca de novos carrapaticidas a partir de produtos vegetais. Assim, acredita-se que o uso de óleos essenciais de plantas medicinais e aromáticas de uma forma isolada ou associada pode reduzir: a velocidade do desenvolvimento da resistência dos carrapatos aos carrapaticidas, os resíduos nos produtos de origem animal e a toxicidade para os animais, aplicadores e meio ambiente.
Assuntos
Plantas Medicinais , Óleos Voláteis , Brasil , RhipicephalusRESUMO
Este trabalho teve como objetivo avaliar o efeito fungitóxico do óleo essencial de capim-citronela e do seu constituinte majoritário citronelal sobre a inibição micelial do fitopatógeno Fusarium subglutinans, agente causal da fusariose da cultura do abacaxi (Ananas comosus). Para avaliar o efeito do óleo essencial no crescimento micelial do fungo, foram utilizadas seis alíquotas (0, 5, 10, 15, 20 e 25 ìL) do óleo e do citronelal que foram distribuídas na superfície do meio BDA (batata-dextrose-ágar) antes da repicagem do fungo. O crescimento micelial foi medido após 48 h de instalação do experimento e em cinco épocas de avaliação (2, 4, 6, 8 e 10 dias após repicagem). Os resultados indicaram que o óleo essencial do capim-citronela demonstrou maior efeito inibitório do crescimento micelial do fungo F. subglutinans do que o composto citronelal. Em todas as alíquotas utilizadas o óleo essencial proporcionou menor taxa de crescimento micelial do que o citronelal.
This study aimed to evaluate the fungitoxic effect of the essential oil of citronella grass and its major constituent citronellal on the inhibition of mycelial pathogen Fusarium subglutinans, the causal agent of Fusarium culture of pineapple (Ananas comosus). To evaluate the effect of essential oil in the mycelial growth of the fungus were used six rates (0, 5, 10, 15, 20 and 25 mL) of oil that were distributed on the surface of PDA medium (potato dextrose agar) before subculturing of the fungus. Mycelial growth was measured after 48 h of the experiment and five times of assessment (2, 4, 6, 8 and 10 days after subculturing). The results indicated that the essential oil of citronella grass showed higher inhibitory effect of mycelial growth of the fungus F. subglutinans than compound citronellal. In all rates used of the essential oil gave lower growth rate than the mycelial citronellal.
Assuntos
Óleos Voláteis/farmacologia , Cymbopogon/metabolismo , Fusarium/isolamento & purificação , Plantas Medicinais/classificaçãoRESUMO
Este trabalho objetivou avaliar a divergência genética entre nove acessos de mentrasto (Ageratum conyzoides) por métodos multivariados utilizando caracteres morfológicos, em quatro épocas de colheita. Os nove acessos de mentrasto foram obtidos de plantas que ocorrem naturalmente nas cinco regiões climáticas do Estado do Tocantins. Em cada época de colheita foram avaliadas as características como biomassa fresca da parte aérea, biomassa seca, área foliar, número de folhas, floração e altura. Pela análise de agrupamento (método de Tocher) foram formados dois grupos na primeira e quarta épocas de colheita, três grupos na segunda época e quatro grupos na terceira época de colheita. Observou-se variação na constituição dos grupos pelos acessos nas épocas de colheita. A divergência genética entre acessos de mentrasto, avaliada por caracteres morfológicos, foi influenciada pelo estádio de desenvolvimento da espécie. A existência de variabilidade entre os acessos coletados em diferentes localidades fornece subsídio para a coleta sistematizada de germoplasma em A. conyzoides no Estado do Tocantins.
This study aimed to analyze the genetic divergence among nine mentrasto (Ageratum conyzoides) accessions by multivariate methods using morphologic traits for four harvesting periods. The nine accessions of mentrasto were obtained from plants that occur naturally in five climatic regions of the state of Tocantins. At each harvesting period, the following traits were evaluated: fresh biomass of the aerial part, dry biomass, leaf area, number of leaves, flowering and height. The grouping analysis (Tocher's method) identified two groups, in the first and fourth harvest periods, three groups in the second harvest period and four groups in the third harvest period. Variation was observed for the group constitutions among the different harvesting periods. The genetic divergence among mentrasto accessions, evaluated by morphologic traits, was influenced by developmental stage of specie. The existence of genetic variability among accessions from different regions supports the systematic collection of A. conyzoides germplasm in the state of Tocantins.