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1.
Phys Chem Chem Phys ; 2024 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-39355900

RESUMO

Gallium sulfide (GaS) stands out as a versatile nonlinear optical material for green-blue optoelectronic and photocatalytic nano-devices. In addition, the in-plane breaking strain and mechanical strength of layered GaS make it a promising candidate for next-generation flexible nanodevices. The fast and reliable assessment of the number of layers, without sample loss, is key for these applications. Here we unveil the influence of dimensionality in the structural, mechanical, and vibrational properties of GaS by applying density-functional theory-based quantum-simulations and group-theory analysis. We find its intralayer structure and interlayer distances are essentially independent of the number of layers, in agreement with the van der Waals forces as dominant interlayer interactions. The translational symmetry breaking along the stacking direction results in different structural symmetries for monolayers, N-odd layers, N-even layers, and bulk geometries. Its force constants against rigid-layer shear, KLSM = 1.35 × 1019 N m-3, and breathing, KLBM = 5.00 × 1019 N m-3, displacements remain the same from bulk to bilayer structures. The related stiffness coefficients in bulk are C44 = 10.2 GPa and C33 = 37.7 GPa, respectively. This insight into GaS interlayer interactions and elastic coefficients reveals it as a promising lubricant for nano-mechanic applications and it is easy to cleave for thickness engineering, even in comparison with layered graphite, MoS2 and other transition metal dichalcogenides and group-IIIA metal monochalcogenides. We present the GaS Raman and infrared spectra dependence on the layer number as strategies for sample thickness characterization and derive formulas for distinguishing the number of layers in both high and low-frequency regimes. In addition, our analysis of their optical-activity selection rules and polarization dependencies is applicable to isostructural group-IIIA metal monochalcogenides with 2H-layer stacking, such as gallium/indium sulphide/selenide. These results contribute to rapid and non-destructive characterization of the material's structure, which is of paramount importance for the manufacturing of devices and the utilization of its diverse properties.

2.
Neotrop Entomol ; 49(4): 604-613, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32761554

RESUMO

Pollinators are threatened all over the planet; scientific data about the status of them is essential for planning conservation and impact mitigation. Appropriate methods and costs for monitoring are being discussed and non-scientist participation in data collection in citizen science (CS) projects is a very promising option. However, there is criticism regarding the quality of data gathered by non-scientists and their real contribution to scientific research, which makes the engagement of scientists in these projects crucial for data verification and validation and training volunteers. CS is still poorly spread in Latin America, so in order to propose strategies to engage scientists, it is necessary to understand the attitude of these professionals towards CS and their interests in engaging in it. To this end, we conducted a survey with 96 biodiversity scientists based in five Latin American countries. In general, the respondents have a very favorable attitude towards CS, although only a small percentage of them are engaged in CS projects. Obtaining data for scientific research is the scientists' main interest in CS, although some of them have also expressed more altruistic reasons for engaging in CS related to ethical and social values. Our paper also suggests five interrelated strategies that can be taken to engage scientists in CS, covering the following: (a) create funding lines to support projects, (b) include extension and outreach activities in the system of scientists' evaluation, (c) promote an inter and transdisciplinary infrastructure, (d) promote scientists' building capacities in CS, and (e) encourage scientists to do science communication.


Assuntos
Atitude , Biodiversidade , Ciência do Cidadão , Polinização , Pesquisadores , Feminino , Humanos , América Latina , Masculino , Inquéritos e Questionários , Voluntários
3.
Neotrop Entomol ; 49(4): 501-510, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32691402

RESUMO

Studies in crop plants analyzing floral biology in conjunction with effectiveness and efficiency of pollinators on pollen transfer and fruit formation are not common, although they are essential to provide better management actions. On this base, we selected a farm in Bahia, Brazil, to study pollination on coffee plants (Coffea arabica L.). Specifically, we want to analyze if nectar traits influence visitor's performance throughout flower lifetime and if honeybees (Apis mellifera scutellata Lepeletier, 1836) are effective and efficient for coffee pollination comparing fertilization and fructification among four experimental treatments: open (OP), wind (WP), cross (HCP), and single-visit bee pollination (SVBP). We found that honeybees collect both nectar and pollen from coffee flowers and transfer pollen on stigmas even after one visit. No differences were found among treatments regarding the number of pollen grains transferred on the stigmas (effectiveness). OP flowers showed a comparative lower efficiency (pollen tubes and fruit set) probably due to pollination failure as those flowers have a higher variability on the number of deposited pollen grains. Two of the treatments (HCP and SVBP) showed higher fertilization (measuring tubes until the end of the style). Pollen loads seem to be limited by a peak of pollen transference by pollinators, followed by the stabilization in the number of pollen grains deposited per stigma. Thus, reproduction of the coffee can be limited by the quality of pollen grains moved by pollinators instead of quantity. Management strategies should focus on monitoring bee density on plants for increasing pollen quality transfer on flowers trough maintaining the adequate proportions of seminatural habitats and/or the number of hives on agricultural fields according to the flowering of the crop.


Assuntos
Abelhas/fisiologia , Coffea/fisiologia , Polinização , Animais , Brasil , Produtos Agrícolas , Flores , Pólen
4.
Braz. j. biol ; Braz. j. biol;80(2): 285-289, Apr.-June 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1132384

RESUMO

Abstract Salinity, of both soil and water, is one of the main causes of crop yield decline. Within this context, the objective of this study was to evaluate the influence of different salts on the germination of chia seeds. The experiment was conducted in a BOD chamber at a constant temperature of 20 °C and in the presence of light. The seeds were placed on paper soaked with aqueous solutions of calcium chloride (CaCl2), sodium chloride (NaCl), potassium chloride (KCl), and magnesium chloride (MgCl2), at the osmotic potentials zero, -0.10, -0.20, -0.30, and -0.40 MPa. The effect of the salinity was evaluated using a germination test, with counts on days 7 and 14 after sowing. Based on the results, chia seeds tolerate concentrations of NaCl to -0.4 MPa and KCl to -0.20 MPa. The salts CaCl2 and MgCl2 had a negative effect on the germination and vigor of the chia seeds for the osmotic potentials -0.30 MPa and -0.20 MPa, respectively.


Resumo A salinidade, tanto dos solos como das águas, é uma das principais causas da queda de rendimento das culturas. Neste contexto, o objetivo deste estudo foi avaliar a influência de diferentes sais na germinação de sementes de chia. O experimento foi conduzido em câmara BOD, na temperatura constante de 20 °C e em presença de luz. As sementes foram colocadas sobre papel embebido em soluções aquosas de cloreto de cálcio (CaCl2), cloreto de sódio (NaCl), cloreto de potássio (KCl) e cloreto de magnésio (MgCl2) nos potenciais osmóticos correspondentes a zero; -0,10; -0,20; -0,30 e -0,40 MPa. O efeito da salinidade foi avaliado através do teste de germinação com contagens aos 7 dias e 14 dias após a semeadura. De acordo com os resultados é possível concluir que as sementes de chia toleram concentrações de NaCl até -0,4 MPa e KCl até -0,20 MPa. Os sais CaCl2 e MgCl2 apresentam efeito negativo sobre a germinação e o vigor das sementes de chia a partir dos potenciais osmóticos de -0,30 MPa e -0,20 MPa, respectivamente.


Assuntos
Cloreto de Sódio , Salinidade , Sementes , Temperatura , Água , Germinação
5.
Braz J Biol ; 80(2): 285-289, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31291400

RESUMO

Salinity, of both soil and water, is one of the main causes of crop yield decline. Within this context, the objective of this study was to evaluate the influence of different salts on the germination of chia seeds. The experiment was conducted in a BOD chamber at a constant temperature of 20 °C and in the presence of light. The seeds were placed on paper soaked with aqueous solutions of calcium chloride (CaCl2), sodium chloride (NaCl), potassium chloride (KCl), and magnesium chloride (MgCl2), at the osmotic potentials zero, -0.10, -0.20, -0.30, and -0.40 MPa. The effect of the salinity was evaluated using a germination test, with counts on days 7 and 14 after sowing. Based on the results, chia seeds tolerate concentrations of NaCl to -0.4 MPa and KCl to -0.20 MPa. The salts CaCl2 and MgCl2 had a negative effect on the germination and vigor of the chia seeds for the osmotic potentials -0.30 MPa and -0.20 MPa, respectively.


Assuntos
Salinidade , Cloreto de Sódio , Germinação , Sementes , Temperatura , Água
6.
Braz. J. Biol. ; 80(2): 285-289, 2020. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-28002

RESUMO

Salinity, of both soil and water, is one of the main causes of crop yield decline. Within this context, the objective of this study was to evaluate the influence of different salts on the germination of chia seeds. The experiment was conducted in a BOD chamber at a constant temperature of 20 °C and in the presence of light. The seeds were placed on paper soaked with aqueous solutions of calcium chloride (CaCl2), sodium chloride (NaCl), potassium chloride (KCl), and magnesium chloride (MgCl2), at the osmotic potentials zero, -0.10, -0.20, -0.30, and -0.40 MPa. The effect of the salinity was evaluated using a germination test, with counts on days 7 and 14 after sowing. Based on the results, chia seeds tolerate concentrations of NaCl to -0.4 MPa and KCl to -0.20 MPa. The salts CaCl2 and MgCl2 had a negative effect on the germination and vigor of the chia seeds for the osmotic potentials -0.30 MPa and -0.20 MPa, respectively.(AU)


A salinidade, tanto dos solos como das águas, é uma das principais causas da queda de rendimento das culturas. Neste contexto, o objetivo deste estudo foi avaliar a influência de diferentes sais na germinação de sementes de chia. O experimento foi conduzido em câmara BOD, na temperatura constante de 20 °C e em presença de luz. As sementes foram colocadas sobre papel embebido em soluções aquosas de cloreto de cálcio (CaCl2), cloreto de sódio (NaCl), cloreto de potássio (KCl) e cloreto de magnésio (MgCl2) nos potenciais osmóticos correspondentes a zero; -0,10; -0,20; -0,30 e -0,40 MPa. O efeito da salinidade foi avaliado através do teste de germinação com contagens aos 7 dias e 14 dias após a semeadura. De acordo com os resultados é possível concluir que as sementes de chia toleram concentrações de NaCl até -0,4 MPa e KCl até -0,20 MPa. Os sais CaCl2 e MgCl2 apresentam efeito negativo sobre a germinação e o vigor das sementes de chia a partir dos potenciais osmóticos de -0,30 MPa e -0,20 MPa, respectivamente.(AU)


Assuntos
Salvia/crescimento & desenvolvimento , Germinação , Estresse Salino
7.
Ceska Gynekol ; 84(3): 201-207, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31324110

RESUMO

OBJECTIVE: To compare the performance of obstetrical interventions and maternal and perinatal outcomes between vaginal and cesarean delivery routes in pregnant women at normal risk. Type of article: Original article. Desing: Cross-sectional study with 421 participants admitted for spontaneous or induced labor with full-term singleton gestations and fetuses weighing between 2,500 and 4,499 g. SETTING: Maternal Fetal-Medicine Service, Assis Chateaubriand Maternity, Federal University of Ceará (UFC), Fortaleza-CE, Brazil. METHODS: The instrument of data collection was divided into socio-demographic, clinical, and obstetric characteristics; data of labor and delivery; maternal morbidity; maternal outcome and perinatal outcomes. Pearsons chi-square test and Fishers exact test were used to verify associations between the groups. RESULTS: The mean age was 22.8 ± 6.0 (vaginal) and 22.9 ± 4.9 (cesarean section). Overall, 44.5% of vaginal deliveries and 85.5% of cesarean sections were monitored electronically (p < 0.001). Immediate skin-to-skin contact (84.1%) and first-hour breastfeeding (80.4%) were more frequent in vaginal deliveries compared with cesarean deliveries (27% vs. 61.0%, p < 0.001). The prevalence of puerperal infections was 1.2% (vaginal) and 5.0% (cesarean section) with a p value of 0.02; 40% of cesarean-delivered newborns and 9.7% of vaginally-delivered newborns were referred to the neonatal intensive care unit (p < 0.001). CONCLUSION: The cesarean section was associated with a lower frequency of useful practices, a higher frequency of harmful practices, worse neonatal outcomes, and a higher rate of postpartum infections.


Assuntos
Cesárea/estatística & dados numéricos , Parto Obstétrico/estatística & dados numéricos , Brasil/epidemiologia , Aleitamento Materno/estatística & dados numéricos , Estudos Transversais , Parto Obstétrico/métodos , Feminino , Humanos , Recém-Nascido , Trabalho de Parto Induzido , Gravidez , Resultado da Gravidez , Infecção Puerperal/epidemiologia
8.
Artigo em Inglês | VETINDEX | ID: vti-742406

RESUMO

Abstract Salinity, of both soil and water, is one of the main causes of crop yield decline. Within this context, the objective of this study was to evaluate the influence of different salts on the germination of chia seeds. The experiment was conducted in a BOD chamber at a constant temperature of 20 °C and in the presence of light. The seeds were placed on paper soaked with aqueous solutions of calcium chloride (CaCl2), sodium chloride (NaCl), potassium chloride (KCl), and magnesium chloride (MgCl2), at the osmotic potentials zero, -0.10, -0.20, -0.30, and -0.40 MPa. The effect of the salinity was evaluated using a germination test, with counts on days 7 and 14 after sowing. Based on the results, chia seeds tolerate concentrations of NaCl to -0.4 MPa and KCl to -0.20 MPa. The salts CaCl2 and MgCl2 had a negative effect on the germination and vigor of the chia seeds for the osmotic potentials -0.30 MPa and -0.20 MPa, respectively.


Resumo A salinidade, tanto dos solos como das águas, é uma das principais causas da queda de rendimento das culturas. Neste contexto, o objetivo deste estudo foi avaliar a influência de diferentes sais na germinação de sementes de chia. O experimento foi conduzido em câmara BOD, na temperatura constante de 20 °C e em presença de luz. As sementes foram colocadas sobre papel embebido em soluções aquosas de cloreto de cálcio (CaCl2), cloreto de sódio (NaCl), cloreto de potássio (KCl) e cloreto de magnésio (MgCl2) nos potenciais osmóticos correspondentes a zero; -0,10; -0,20; -0,30 e -0,40 MPa. O efeito da salinidade foi avaliado através do teste de germinação com contagens aos 7 dias e 14 dias após a semeadura. De acordo com os resultados é possível concluir que as sementes de chia toleram concentrações de NaCl até -0,4 MPa e KCl até -0,20 MPa. Os sais CaCl2 e MgCl2 apresentam efeito negativo sobre a germinação e o vigor das sementes de chia a partir dos potenciais osmóticos de -0,30 MPa e -0,20 MPa, respectivamente.

9.
Eur J Pharm Sci ; 123: 295-300, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30026093

RESUMO

In this study, we report the antibacterial activity and modulation of antibiotic activity by Fe2(MoO4)3 microstructures obtained by the hydrothermal route without use of surfactants or organic additives. This material was characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM) images. The XRD pattern showed that the Fe2(MoO4)3 crystallize in a monoclinic structure without secondary phases. Raman spectroscopy confirms the formation of Fe2(MoO4)3. SEM images show that the Fe2(MoO4)3 obtained have ball-of-yarn shaped morphology. In the antibacterial assays, strains of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were assayed by microdilution method to evaluate the antibacterial and modulatory-antibiotic activity with antibiotics as gentamicin, norfloxacin and imipenem. Against all bacteria, the Minimum Inhibitory Concentration (MIC) was Fe2(MoO4)3 ≥ 1024 µg/mL. This high MIC result must be associated with the fact of the iron be an essential microelement to the bacterial growth. However, when the Fe2(MoO4)3 was assayed in association with the antibiotics was observed an antagonistic effect demonstrated by an enhance of the MIC. This fact is associated directly with the pro-oxidative properties of metallic oxides. These compounds enhance the production of free radicals, as H2O2 and superoxide ions that can affect the cell structures as cell membrane and cell wall. Other effect is associated with the possible coordination of the metal, performing bonds with the chemical structure of the antibiotics, reducing their activity. Our results indicated that nanocompounds as Fe2(MoO4)3 can not be used as antimicrobial products for clinical usage, neither directly and neither in association with antibiotics.


Assuntos
Antibacterianos/farmacologia , Compostos Férricos/farmacologia , Molibdênio/farmacologia , Nanopartículas , Antibacterianos/química , Antibacterianos/toxicidade , Química Farmacêutica/métodos , Cristalização , Composição de Medicamentos , Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Compostos Férricos/química , Compostos Férricos/toxicidade , Testes de Sensibilidade Microbiana , Estrutura Molecular , Molibdênio/química , Molibdênio/toxicidade , Oxirredução , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Relação Estrutura-Atividade
10.
Artigo em Inglês | MEDLINE | ID: mdl-28802161

RESUMO

In this paper we performed the study of two coprolites (fossilized feces) collected from the exposed levels of the Pedra de Fogo Formation, Parnaiba Sedimentary Basin, and Rio do Rasto Formation, Paraná Sedimentary Basin, both of the Palaeozoic era (Permian age). They were characterized using X-ray diffractometry, infrared, Raman and energy dispersive spectroscopy techniques in order to aid our understanding of the processes of fossilization and to discuss issues related to the feeding habits of the animals which generated those coprolites, probably cartilaginous fishes. The results obtained using a multitechnique approach showed that although these coprolites are from different geological formations, 3000km away from each other, they show the same major crystalline phases and elemental composition. The main phases found were hydroxyapatite, silica, calcite and hematite, which lead to infer that those coprolites were formed under similar conditions and produced by a similar group of carnivore or omnivore fishes.


Assuntos
Fenômenos Químicos , Fezes/química , Fósseis , Animais , Brasil , Imagem Óptica , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Difração de Raios X
11.
Braz. j. biol ; Braz. j. biol;2017.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467291

RESUMO

Abstract Salinity, of both soil and water, is one of the main causes of crop yield decline. Within this context, the objective of this study was to evaluate the influence of different salts on the germination of chia seeds. The experiment was conducted in a BOD chamber at a constant temperature of 20 °C and in the presence of light. The seeds were placed on paper soaked with aqueous solutions of calcium chloride (CaCl2), sodium chloride (NaCl), potassium chloride (KCl), and magnesium chloride (MgCl2), at the osmotic potentials zero, -0.10, -0.20, -0.30, and -0.40 MPa. The effect of the salinity was evaluated using a germination test, with counts on days 7 and 14 after sowing. Based on the results, chia seeds tolerate concentrations of NaCl to -0.4 MPa and KCl to -0.20 MPa. The salts CaCl2 and MgCl2 had a negative effect on the germination and vigor of the chia seeds for the osmotic potentials -0.30 MPa and -0.20 MPa, respectively.


Resumo A salinidade, tanto dos solos como das águas, é uma das principais causas da queda de rendimento das culturas. Neste contexto, o objetivo deste estudo foi avaliar a influência de diferentes sais na germinação de sementes de chia. O experimento foi conduzido em câmara BOD, na temperatura constante de 20 °C e em presença de luz. As sementes foram colocadas sobre papel embebido em soluções aquosas de cloreto de cálcio (CaCl2), cloreto de sódio (NaCl), cloreto de potássio (KCl) e cloreto de magnésio (MgCl2) nos potenciais osmóticos correspondentes a zero; -0,10; -0,20; -0,30 e -0,40 MPa. O efeito da salinidade foi avaliado através do teste de germinação com contagens aos 7 dias e 14 dias após a semeadura. De acordo com os resultados é possível concluir que as sementes de chia toleram concentrações de NaCl até -0,4 MPa e KCl até -0,20 MPa. Os sais CaCl2 e MgCl2 apresentam efeito negativo sobre a germinação e o vigor das sementes de chia a partir dos potenciais osmóticos de -0,30 MPa e -0,20 MPa, respectivamente.

12.
Spectrochim Acta A Mol Biomol Spectrosc ; 157: 124-128, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26745511

RESUMO

Fossils are mineralized remains or traces from animals, plants and other organisms aged to about 10(8)years. The chemical processes of fossilization are dated back from old geological periods on Earth. The understanding of these processes and the structure of the fossils are one of the goals of paleontology and geology in the sedimentary environments. Many researches have tried to unveil details about special kinds of biological samples; however, a lack of data is noticed for various other specimens. This study reports the investigations through infrared spectroscopy, X-ray fluorescence and X-ray diffraction measurements for two types of fish fossils from the Cretaceous Period. The sample of Cladocyclus gardneri and Vinctifer comptoni fossils were collected from the Ipubi Formation, being one of the less studied, among the formations that constitute the important Santana group in the Araripe Basin, Brazil. The results obtained through different techniques, showed that the C. gardneri fish fossil contains hydroxyapatite and calcite as constituents whereas its rock matrix was formed by calcite, quartz and pyrite. Regarding the V. comptoni, the measurements confirmed the presence of hydroxyapatite in the fossil and its rock matrix gypsum, pyrite, quartz and calcite. The above scientific data contributed to the understanding the fossil formation in the Ipubi Formation, an important environment of the Cretaceous Period, which is rich in well-preserved fossils from different species.


Assuntos
Peixes , Fósseis , Espectrometria por Raios X , Difração de Raios X , Animais , Brasil , Extinção Biológica , Peixes/anatomia & histologia , Fósseis/anatomia & histologia , Espectrometria por Raios X/métodos , Espectrofotometria Infravermelho/métodos , Difração de Raios X/métodos
13.
Rev. bras. plantas med ; Rev. bras. plantas med;17(4,supl.3): 1182-1186, 2015. tab, graf
Artigo em Português | LILACS | ID: lil-776604

RESUMO

RESUMO A Salvia hispanica, conhecida popularmente como chia, apresenta elevada notabilidade por suas características nutricionais, sendo rica em proteínas, fibras, sais minerais e ácidos graxos, os quais podem ser responsáveis pela diminuição do risco de doenças cardiovasculares. Apesar do crescente consumo, existem poucos estudos em relação à germinação e ao vigor de suas sementes. Assim, o presente trabalho teve como objetivo avaliar os efeitos da luz e da temperatura no potencial fisiológico de sementes de chia (Salvia hispanica L.). Para tal, as sementes foram colocadas para germinar nas temperaturas constantes de 20, 25 e 30 ºC na presença e ausência de luz. Os parâmetros avaliados foram: percentagem de germinação, primeira contagem, índice de velocidade de germinação, e comprimento e massa seca das plântulas. O delineamento experimental utilizado foi inteiramente casualizado com quatro repetições de 100 sementes. Constatou-se que a germinação das sementes de chia ocorre tanto na presença quanto na ausência de luz. As sementes de chia, sem dormência, germinam melhor na temperatura constante de 20 °C.


ABSTRACT The Salvia hispanica, known as chia, has high notability for its nutritional features, being rich in protein, fiber, minerals and fatty acids, which can be responsible for reducing the risk of cardiovascular diseases. Although the consumption of the seed is increasing, there are few studies about the germination and vigor of the seeds. The aim of this study was to evaluate the effects of light and temperature on the physiologic potentiality of chia seeds (Salvia hispanica L.). The seeds were sowed on paper at constant temperatures of 20, 25 and 30 ºC in the presence or absence of light. The parameters evaluated were the following: percentage of germination, first count, germination speed index, length, and dry weight of the seedlings. The experimental design used was of complete randomized plots with four replications of 100 seeds. The germination of the chia seeds occurred in the presence or absence of light. The chia seeds, without dormancy, germinated better at the constant temperature of 20 ºC.


Assuntos
Temperatura , Lamiaceae/classificação , Plantas Medicinais/classificação , Sementes/classificação
14.
Artigo em Inglês | MEDLINE | ID: mdl-23856041

RESUMO

In this work we study two types of wood fossils (Gymnosperms, Araucariaceae) from the Crato Formation of Araripe Basin in Brazil, from the Cretaceous Period. The samples were characterized by Raman and infrared spectroscopies, X-ray diffraction and scanning electron microscopy. The results obtained by different techniques showed that although the rocks surrounding the fossils have predominantly the same constitution - calcite - however, the formation processes of these types of wood fossils are quite different. One of the fossils, denominated as light wood, is predominantly composed of gypsum, while the other fossil, the dark wood, is rich in amorphous carbon, possibly the kerogen type. Implications relative to the environment where the plants lived millions years ago are also given. Finally, the results highlight the constitution of one of the most important paleontological sites of the Cretaceous Period in the South America.


Assuntos
Fósseis , Fenômenos Geológicos , Madeira/química , Brasil , Imagem Óptica , Espectrofotometria Infravermelho , Análise Espectral Raman , Fatores de Tempo , Madeira/ultraestrutura , Difração de Raios X
15.
Braz J Biol ; 71(1): 107-13, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21437406

RESUMO

Previous studies have shown the superior competitive ability of honeybees compared with native bees in the exploitation of floral resources and nesting sites besides their low efficiency in pollinating native plant species. However, there is little evidence of the effect of this invading species on autochthonous plant populations in natural environments. Thus experiments were performed to test the pollination efficiency of honeybees in two species of Jatropha (Euphorbiaceae), J. mollissima (Pohl) Baill. and J. mutabilis (Pohl) Baill., after a single flower visitation. Samplings were carried out between March and April 2006 in a hyperxerophilous shrub-arboreal Caatinga at Estação Biológica de Canudos, Bahia (9º 56´ 34" S, 38º 59´ 17" W), the property of Fundação Biodiversitas. Apis mellifera was efficient at pollinating J. mollissima (100%) and J. mutabilis (85%). This high efficiency may be explained by 1) the simple floral characteristics of both plant species, which facilitate access to the sexual organs of the plant; and 2) the body size of A. mellifera that fits the flower's dimensions.


Assuntos
Abelhas/fisiologia , Comportamento Animal/fisiologia , Jatropha/fisiologia , Polinização/fisiologia , Animais , Brasil , Flores , Sementes/crescimento & desenvolvimento
16.
Genet Mol Res ; 10(1): 65-74, 2011 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-21264817

RESUMO

Adrenoleukodystrophy is a neurodegenerative X-linked recessive disorder. It is characterized by abnormal function of peroxisomes, which leads to an accumulation of very long-chain fatty acids in plasma and tissues, especially in the cortex of adrenal glands and white matter of the central nervous system, causing demyelinating disease and adrenocortical insufficiency (Addison's disease). It is caused by a mutation in the ABCD1 gene (ATP-binding cassette, subfamily D, member 1), which encodes the protein adrenoleukodystrophy that is involved in the transport of fatty acids into the peroxisome for degradation. Variable expression has been recognized in families of patients who have this disease. A Brazilian family from Minas Gerais State, Brazil, was studied. The proband is an adult living in Minas Gerais State, Brazil; he had adrenomyeloneuropathy, adrenocortical insufficiency and a stable cerebral form. DNA was extracted from a blood sample and was sequenced to identify the mutation. The patient's exons were cloned for confirmation. A new mutation was found in exon 5 of the ABCD1 gene (c.1430delA), as well as a single-nucleotide polymorphism in exon 6. The mutation causes a frame shift, resulting in a truncated protein with almost total absence of the ATP binding domain.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Adrenoleucodistrofia/genética , Éxons , Deleção de Sequência , Membro 1 da Subfamília D de Transportadores de Cassetes de Ligação de ATP , Adulto , Sequência de Bases , Brasil , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/genética , Humanos , Masculino , Linhagem , Polimorfismo de Nucleotídeo Único
17.
Braz J Biol ; 70(3): 671-6, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20730356

RESUMO

We present the first records on pollination biology of Jacquemontia montana (Moric.) Meisn. (Convolvulaceae), a widespread climber in the Chapada Diamantina. Our objectives were to (1) characterise flower morphology and biology of J. montana; (2) sample flower visitors and (3) make inferences about potential pollinators, based on foraging behaviour. Observations and sampling were performed on two patches from 8:00 AM to 3:30 PM, May 15th to 16th, 2007. The corolla is bowl shaped, pentamerous, gamopetalous, actinomorphic, and yellow, with a mean diameter of 22.43 +/- 1.81 mm, the depth being variable during flower phases. Stigma receptivity lasted from 8:00 AM-3:30 PM and pollen viability from 9:00 AM-3:30 PM Pollen. showed great decline in number but not in viability during anthesis. Nectarivorous (Coleoptera, Diptera, Hymenoptera) and herbivorous (Orthoptera) insects were found on the flowers. Both male and female bees (Dialictus spp., Robertson 1902) were the most frequent flower visitor. The bees' behaviour, and time spent on flowers, varied according to the resource gathered (i.e., pollen or nectar). The Dialictus species are likely to be the main pollinator of J. montana, considering the frequency, contact with reproductive parts, and carrying only J. montana pollen spread over the ventral part of the thorax, abdomen and legs. Although not quantified, nectar may still be available in the afternoon, considering the behaviour of bees on flowers during this time. Pollen:ovule ration that was1.200:4, suggests facultative xenogamy.


Assuntos
Convolvulaceae/fisiologia , Flores/fisiologia , Polinização/fisiologia , Animais , Brasil , Besouros/fisiologia , Dípteros/fisiologia , Feminino , Himenópteros/fisiologia , Masculino , Ortópteros/fisiologia , Pólen/fisiologia , Reprodução/fisiologia
18.
Rev. argent. cir ; 96(3-4): 143-152, mar.-abr. 2009. tab
Artigo em Espanhol | BINACIS | ID: bin-124513

RESUMO

Antecedentes: La cirugía laparoscópica ha modificado el manejo de la patología colorrectal. Objetivo: Analizar los resultados a corto plazo obtenidos con el abordaje laparoscópico de la patología colorrectal. Lugar de aplicación: Sección de coloproctología, Hospital Privado. Diseño: Cohorte, retrospectivo. Población: 300 pacientes (mediana de edad 62 años, 51,4% de mujeres) tratados mediante abordaje laparoscópico entre marzo de 2003 y abril 2007. Método: Análisis de una base de datos prospectiva. Conversión, readmisión hospitalaria y complicaciones posoperatorias fueron analizadas en base a las características demográficas, tipo de procedimiento efectuado y curva de aprendizaje. Se realizó un análisis multivariado para detectar factores asociados a conversión. Resultados: Conversión global: 15%. La resección anterior mostró un índice de conversión significativamente mayor al del resto de los procedimientos (29%, p=2.02). No observamos diferencias a lo largo de nuestra curva de aprendizaje, a excepción de una disminución del tiempo operatorio. Estadía hospitalaria: 3 días. Morbilida global: 19,6%. Las complicaciones postoperatorias más frecuentes fueron el íleo (9%), la infección de herida (2,3%) y la fístula anastomótica (1,3%). Mortalidad: 0.6%. Los hombres se convirtieron del doble que las mujeres (p=0.01) y se complicaron más (p=0.006). El sexo, el IMC y el tipo de procedimiento resultaron ser actores asociados a conversión. Conclusiones: La cirugía laparoscópica ha logrado trasladar los beneficios del abordaje nininvasivo al manejo de la patología colorrectal. Distintos factores pueden modificar sus resultados a corto plazo, especialmente en términos de conversión. El conocimiento de éstos puede contribuir a una adecuada selección de los casos.(AU)


Assuntos
Humanos , Masculino , Adulto , Feminino , Laparoscopia , Cirurgia Colorretal/instrumentação , Avaliação de Resultado de Intervenções Terapêuticas , Complicações Pós-Operatórias
19.
Rev. argent. cir ; 96(3/4): 143-152, mar.-abr. 2009. tab
Artigo em Espanhol | LILACS | ID: lil-552600

RESUMO

Antecedentes: La cirugía laparoscópica ha modificado el manejo de la patología colorrectal. Objetivo: Analizar los resultados a corto plazo obtenidos con el abordaje laparoscópico de la patología colorrectal. Lugar de aplicación: Sección de coloproctología, Hospital Privado. Diseño: Cohorte, retrospectivo. Población: 300 pacientes (mediana de edad 62 años, 51,4% de mujeres) tratados mediante abordaje laparoscópico entre marzo de 2003 y abril 2007. Método: Análisis de una base de datos prospectiva. Conversión, readmisión hospitalaria y complicaciones posoperatorias fueron analizadas en base a las características demográficas, tipo de procedimiento efectuado y curva de aprendizaje. Se realizó un análisis multivariado para detectar factores asociados a conversión. Resultados: Conversión global: 15%. La resección anterior mostró un índice de conversión significativamente mayor al del resto de los procedimientos (29%, p=2.02). No observamos diferencias a lo largo de nuestra curva de aprendizaje, a excepción de una disminución del tiempo operatorio. Estadía hospitalaria: 3 días. Morbilida global: 19,6%. Las complicaciones postoperatorias más frecuentes fueron el íleo (9%), la infección de herida (2,3%) y la fístula anastomótica (1,3%). Mortalidad: 0.6%. Los hombres se convirtieron del doble que las mujeres (p=0.01) y se complicaron más (p=0.006). El sexo, el IMC y el tipo de procedimiento resultaron ser actores asociados a conversión. Conclusiones: La cirugía laparoscópica ha logrado trasladar los beneficios del abordaje nininvasivo al manejo de la patología colorrectal. Distintos factores pueden modificar sus resultados a corto plazo, especialmente en términos de conversión. El conocimiento de éstos puede contribuir a una adecuada selección de los casos.


Assuntos
Humanos , Masculino , Adulto , Feminino , Laparoscopia , Cirurgia Colorretal/instrumentação , Avaliação de Resultado de Intervenções Terapêuticas , Complicações Pós-Operatórias
20.
Rev. argent. cir ; 95(3/4): 133-145, 2008.
Artigo em Espanhol | LILACS | ID: lil-523790

RESUMO

Objetivo: Presentar la experiencia preliminar en el tratamiento de la carcinomatosis peritoneal de origen gastrointestinal y ginecológico. Métodos: El estudio incluye 11 pacientes portadores de carcinomatosis, tratados por medio de citorreducción y quimioterapia hipertérmica intraoperatoria y operados entre enero del 2005 y enero del 2008. Resultados: La mediana de edad de los pacientes fue de 50 años (rango = 22-56) y pertenecieron al sexo masculino el 54.5%. La mediana de duración del procedimiento citorreductivo fue de 630 min (rango 205-840). La citorreducción completa fue obtenida en el 54,6% (6/11) de los pacientes. La mediana de órganos resecados por paciente fue 4 (rango = 2 - 5) y la mediana de peritonectomia por paciente fue de 3 (rango = 0-6). Las drogas utilizadas para el baño hipertérmico fueron la Mitomicina C en las carcinomatosis por cancer de colon y del apéndice y el Cisplatino en carcinomatosis por cáncer de ovario. El tiempo d irrigación fue de 90 min y la mediana de la temperatura alcanzada fue de 41º C (39ºC - 43ºC). La mortalidad posoperatoria fue del 9,1% (1/11) y la morbilidad del 63,6% (7/11). La mediana de internación fue de 10 días (4-67), en los pacientes complicados la media de internación fue de 44 días para las severas y de 9 días para las leves. La supervivencia libre de tumor fue del 30% (mediana de seguimiento de 8,3 meses).


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Carcinoma/cirurgia , Neoplasias Gástricas/patologia , Neoplasias Ovarianas/patologia , Neoplasias Peritoneais/cirurgia , Neoplasias do Colo/patologia , Carcinoma/secundário , Carcinoma/terapia , Cisplatino/uso terapêutico , Hipertermia Induzida , Mitomicina/uso terapêutico
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