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1.
Rev Neurol ; 78(12): 343-354, 2024 Jun 16.
Artigo em Espanhol | MEDLINE | ID: mdl-38867683

RESUMO

INTRODUCTION: At least 20% of paediatric patients with epilepsy present resistance to multiple anti-crisis drugs in trials, which has a negative impact on their neuropsychological state, quality of life and prognosis; it is therefore necessary to document their neuropsychological profile in order to improve the clinical approach to them. AIMS: To describe the neuropsychological profile (cognitive, academic, behavioural, emotional, adaptive, sleep disturbances and quality of life) of paediatric patients with drug-resistant focal epilepsy in the frontal, temporal and occipital lobes, and to compare performance between patients with frontal and temporal foci, and to assess the link between the duration of the condition, the frequency of seizures and the amount of anti-crisis drugs and the neuropsychological profile. PATIENTS AND METHODS: The neuropsychological profile of 19 paediatric patients with a diagnosis of pharmacoresistant epilepsy with a mean age of 10.89 years was evaluated. RESULTS: 57.9% of the 19 patients were men. 63.2% presented frontal focus; 26.3% presented temporal focus; and 10.5% presented occipital focus. Deficiencies in attention, comprehension, verbal memory, working memory and processing speed, in addition to adaptive difficulties were observed. When the patients with frontal and temporal focus were compared, the former were found to present greater deficits in planning, while the patients with temporal focus presented more severe symptoms of anxiety. Patients with a longer disease duration were found to present greater impairment to their intelligence quotient and adaptive behavioural skills. CONCLUSIONS: Pharmacoresistant epilepsy in paediatric patients affects intelligence quotient and adaptive skills, as well as attention, memory and executive functions, and neuropsychological intervention programmes must therefore be implemented to improve these patients' quality of life.


TITLE: Perfil neuropsicológico de pacientes pediátricos mexicanos con epilepsia focal farmacorresistente.Introducción. Al menos el 20% de los pacientes pediátricos con epilepsia muestra resistencia a los ensayos de múltiples fármacos anticrisis, que impactan negativamente en su estado neuropsicológico, calidad de vida y pronóstico; por tal motivo, es necesario documentar ampliamente su perfil neuropsicológico para mejorar su abordaje clínico. Objetivos. Describir el perfil neuropsicológico (cognitivo, académico, conductual, emocional, adaptativo, alteraciones del sueño y calidad de vida) de pacientes pediátricos con epilepsia focal farmacorresistente de los lóbulos frontal, temporal y occipital, así como comparar el desempeño entre los pacientes con foco frontal y temporal, y evaluar la asociación entre la duración del padecimiento, la frecuencia de las crisis y la cantidad de fármacos anticrisis con el perfil neuropsicológico. Pacientes y métodos. Se evaluó el perfil neuropsicológico de 19 pacientes pediátricos con diagnóstico de epilepsia farmacorresistente, con una edad promedio de 10,89 años. Resultados. De los 19 pacientes, el 57,9% fueron hombres. El 63,2% presentó foco frontal; el 26,3%, temporal; y el 10,5%, occipital. Se encontraron deficiencias en atención, comprensión, memoria verbal, memoria de trabajo y velocidad de procesamiento, además de dificultades adaptativas. Al comparar a los pacientes con foco frontal y temporal, se encontró que los primeros presentaron mayores deficiencias en planificación, mientras que los pacientes con foco temporal presentaron mayores síntomas de ansiedad. Con respecto a la duración de la enfermedad, se encontró que los pacientes con mayor duración del padecimiento presentaron mayor afectación en el cociente intelectual y en las habilidades en la conducta adaptativa. Conclusiones. La epilepsia farmacorresistente en pacientes pediátricos afecta el cociente intelectual y las habilidades adaptativas, así como a la atención, la memoria y las funciones ejecutivas, por lo que es necesaria la implementación de programas de intervención neuropsicológica para mejorar la calidad de vida de estos pacientes.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsias Parciais , Testes Neuropsicológicos , Humanos , Masculino , Criança , Feminino , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Epilepsia Resistente a Medicamentos/psicologia , Epilepsias Parciais/tratamento farmacológico , Epilepsias Parciais/psicologia , México , Adolescente , Qualidade de Vida , Pré-Escolar
2.
Heliyon ; 9(8): e18738, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37560687

RESUMO

Lentinus crinitus (L.) Fr is a wild macrofungus that is popular as antimicrobial and various biological activities. This study aims to determine the capacity growth stimulation of Lactobacillus paracasei and antimicrobial activity of aqueous extracts of L. crinitus obtained from wild basidiomata, mycelial biomass by liquid fermentation and spent mushroom substrate obtained by solid-state fermentation. The antimicrobial activity was investigated against bacterial and fungal pathogens and growth stimulation L. paracasei probiotic bacterium. The total carbohydrate and ß-glucan contents of the extracts were determined using colorimetric analysis. The aqueous extracts obtained showed inhibition against Fusarium oxysporum., Penicillium sp., Rhizopus oryzae, Aspergillus niger, Escherichia coli and Salmonella typhimurium. The aqueous extract obtained from wild basidiomata, and mycelial biomass showed the highest percentage of stimulation of L. paracasei growth in 48 h. The extracts obtained from L. crinitus have antimicrobial potential and stimulating capacity of the probiotic Lactobacillus paracasei. Additionally, different biotechnological techniques such as liquid and solid-state fermentation can be used to obtain aqueous extracts.

3.
Syst Parasitol ; 100(1): 59-67, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36242720

RESUMO

A new species of Trichobius Gervais, 1844 (Diptera: Streblidae) is described from specimens collected in Jalisco, Mexico, from host bat Choeronycteris mexicana Tschudi. We place the new species within the "dugesii" group, because it shares certain characteristics with Trichobius urodermae Wenzel, 1966 T. angulatus Wenzel, 1976 and T. tiptoni Wenzel, 1976. However, it is easy to differentiate from all known species due to the chaetotaxy of the thorax, in which the prescutal and lateral setae are very long, while the discal setae are abruptly smaller and denser. It also possesses the metasternal lobe, which is very broad and translucent. We found a male of Paratrichobius americanus Peterson & Ross, 1972 on the same host individual, which expands the distribution area of P. americanus into Mexico because the unique holotype was collected in Arizona.


Assuntos
Quirópteros , Dípteros , Masculino , Animais , México , Especificidade da Espécie , Arizona
4.
Rev Cient Odontol (Lima) ; 11(1): e140, 2023.
Artigo em Espanhol | MEDLINE | ID: mdl-38288318

RESUMO

AIM: To analyze stress in a metal-ceramic, zirconia and lithium disilicate implant-supported unitary fixed partial prosthesis in the first lower premolar through finite element analysis at a 500 N force. MATERIALS AND METHODS: Three study models were carried out, metal-ceramic, lithium disilicate and zirconium implant-supported crowns in the first lower premolar. The dental implant was made of titanium grade 5 based on the Bolt® model of UniDentalDirect with internal grooved connection (18 grooves) and the implant had a size of 11,0 x 4,5 mm, preformed abutment and integrated screw. The three designs had vertical and oblique (45°) forces applications at 500 N. The geometric modeling was performed with the SolidWorks® 2017 program and the results were obtained through the Von mises analysis using the CosmoWorks®2017 program. RESULTS: The lowest value of maximum stress on crown level, under vertical and oblique forces, was found in the lithium disilicate crown with 21,9 MPa and 33,2 MPa, and with a minimum difference with the zirconium crown with 22,1 MPa and 35,1 MPa; on the abutment level, the zirconium crown had the lowest value of maximum stress with 18,6 MPa and 28,1 MPa; at the screw level, there were no significant differences. CONCLUSION: Metal-ceramic, lithium disilicate, and zirconia crowns proved to be materials of good compressive and tensile strength, but it was concluded that the zirconia crown design generated lower overall stress.

5.
Trop Biomed ; 39(4): 575-578, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36602218

RESUMO

Malaria and dengue fever are among the most common mosquito-borne diseases worldwide; however, reports of coinfection are rare. We present a case of severe malaria and dengue coinfection in a 16-yearold female patient presenting with fever, thrombocytopenia, pleural effusion, myopericarditis, and acute respiratory distress syndrome. Dengue infection was confirmed by the presence of immunoglobin M antibodies and nonstructural protein 1, while malaria was confirmed by the presence of Plasmodium vivax in thick and thin blood smears. This is the first report of a dengue/malaria coinfection in Mexico.


Assuntos
Coinfecção , Doenças Transmissíveis , Vírus da Dengue , Dengue , Malária Vivax , Malária , Animais , Humanos , Feminino , Adolescente , Plasmodium vivax , Coinfecção/diagnóstico , México , Dengue/complicações , Dengue/diagnóstico , Malária Vivax/complicações , Malária Vivax/diagnóstico
8.
Chemosphere ; 261: 127798, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32750617

RESUMO

Mining activities lead to important physical, chemical and biological effects on soil properties, generating severe impacts in the establishment and maintenance of vegetation. Assisted phytoremediation can be considered an environmentally friendly approach for soil remediation. In this study, two mining soils (PORT and GAM) were treated with 10%, by mass, of the following amendments: manure biochars prepared at 450 °C (BMW450) and 600 °C (BMW600), hydrochars prepared by hydrothermal carbonization (HTC) of manure at 190 °C (HWM190) and 240 °C (HMW240) and manure waste (MW). Brassica napus was used as a phytoextraction species. After 45 days of plant growth, soil samples were widely characterized, including microbial biomass carbon, enzymatic activity and metal content. In addition, plant biomass production, bioconcentration factor, translocation factor and metal uptake were determined. Experimental results showed that addition of biochars improved the As uptake by Brassica napus in both soils but just in the roots increasing bioconcentration factor between 22.1 and 39.5% for GAM soil and between 28.6 and 53.4% for PORT soil. Brassica napus cannot be considered as Zn accumulator in GAM soil samples and in the case of PORT samples, only the addition of BMW600 and HMW240 enhanced the phytoextraction process of Zn on the roots. Soil enzyme activity improved in hydrochar amended soils.


Assuntos
Biodegradação Ambiental , Brassica napus/crescimento & desenvolvimento , Carvão Vegetal/química , Esterco , Poluentes do Solo/análise , Biomassa , Carbono/farmacologia , Metais/farmacologia , Mineração , Solo/química
9.
Heliyon ; 6(3): e03502, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32181387

RESUMO

In Colombia, despite the great diversity of mushrooms, most are yet unknown from the taxonomic point of view, and even less known from their nutritional composition or their possible application to obtain value-added products from agro-waste. The mycelial growth of Lentinus crinitus (L.) Fr strain was investigated on agro-waste in culture media agar and correlation analyses were performed. The proximate and mineral element composition was determinate in wild mushrooms and spent substrate of L. crinitus, obtained in the solid-state fermentation. The evaluation of the mycelial growth of the L. crinitus strain confirmed that it can grow on agro-waste. The treatment T6 (Orange peel and brand) was determined to be the best for the mycelial growth of L. crinitus (0.0790 cm/h), T7 (Bran, Orange peel and rice husk) and T5 (Rice hush and orange peel) followed, with mycelial growth rates of 0.0753 cm/h and .0720 cm/h, respectively. The growth rate was positively correlated with C/N ratios but negatively correlated with Zn, N and protein. The combination of the agro-waste (T6, T7 and T5) were used to obtain the spent substrate and assess its nutritional potential. The results showed that wild mushrooms of L. crinitus had protein contents of 14.42%, and fiber of 57.18%. The spent substrate of L. crinitus increased their protein content (10.5-11.22%), fiber (44.1-56%) and nitrogen (1.64-1.28%). These advances are promising for the use of L. crinitus as degrader of agro-waste to obtain different products of food and agro-industrial interest.

10.
Rev Gastroenterol Mex (Engl Ed) ; 83(1): 25-30, 2018.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-28551084

RESUMO

INTRODUCTION: The prevalence of Barrett's esophagus has been calculated at between 1.3 and 1.6%. There is little information with respect to this in Mexico. AIM: To determine the frequency and characteristics of Barrett's esophagus in patients that underwent endoscopy at a national referral center, within a 10-year time frame. MATERIAL AND METHODS: The databases of the pathology and gastrointestinal endoscopy departments of the Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán" were analyzed, covering the period of January 2002 to December 2012. Patients with a histologic diagnosis of Barrett's esophagus were included. The variables of age, sex, the presence of dysplasia/esophageal adenocarcinoma, Barrett's esophagus length, and follow-up were analyzed. RESULTS: Of 43,639 upper gastrointestinal endoscopies performed, 420 revealed Barrett's esophagus, corresponding to a frequency of 9.6 patients for every 1,000 endoscopies. Of those patients, 66.9% (n=281) were men, mean patient age±SD was 57.2±15.3 years, 223 patients (53%) presented with long-segment Barrett's esophagus, and 197 (47%) with short-segment Barrett's esophagus. Dysplasia was not present in 339 patients (80.7%). Eighty-one (19.3%) patients had some grade of dysplasia or cancer: 48/420 (11.42%) presented with low-grade dysplasia, 20/420 (4.76%) with high-grade dysplasia, and 13/420 (3.1%) were diagnosed with esophageal cancer arising from Barrett's esophagus. Mean follow-up time was 5.6 years. CONCLUSIONS: The frequency of Barrett's esophagus was 9.6 cases for every 1,000 upper gastrointestinal endoscopies performed. Dysplasia was not documented in the majority of the patients with Barrett's esophagus and they had no histopathologic changes during follow-up. A total of 19.3% of the patients presented with dysplasia or cancer.


Assuntos
Esôfago de Barrett/diagnóstico , Esôfago de Barrett/epidemiologia , Adulto , Idoso , Esôfago de Barrett/patologia , Esôfago de Barrett/terapia , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Centros de Atenção Terciária
11.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;51(2): e6784, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-889027

RESUMO

Studies have suggested that total energy intake and diet composition affect lifespan and ageing. A high-fat diet induces oxidative stress and affects the development of diseases. In contrast, antioxidants are capable of reducing its harmful effects. Yerba mate beverages are an important source of antioxidants, but there is scarce knowledge about their effects on suppressing fat accumulation. Here, we investigated the compounds present in yerba mate extracts and assessed their effects on Drosophila melanogaster given a high cholesterol diet. LS-ESI-MS analysis showed the presence of matesaponins, phenolic compounds and methylxanthines in all of the examined extracts. In Drosophila, under extract treatment conditions, the mean lifespan was significantly extended from 38 to 43 days, there was an increase in the ability to support induced stress and decrease in lipid peroxidation products. Moreover, yerba mate extracts recovered the glutathione S-transferases (GST) activity and reduced the cholesterol level. Taken together, our results support that extracts can extend lifespan by reducing the detrimental effect of a high-fat diet in D. melanogaster, and this outcome can be associated with the compound content in the extracts. This study improves the understanding of natural interventions that reduce stress-induced oxidative damage, which is fundamental in promoting healthy ageing.


Assuntos
Animais , Extratos Vegetais/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ilex paraguariensis/química , Drosophila melanogaster/fisiologia , Longevidade/efeitos dos fármacos , Antioxidantes/farmacologia , Estresse Oxidativo/fisiologia , Drosophila melanogaster/crescimento & desenvolvimento , Dieta Hiperlipídica , Longevidade/fisiologia
12.
Braz J Med Biol Res ; 51(2): e6784, 2017 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-29211252

RESUMO

Studies have suggested that total energy intake and diet composition affect lifespan and ageing. A high-fat diet induces oxidative stress and affects the development of diseases. In contrast, antioxidants are capable of reducing its harmful effects. Yerba mate beverages are an important source of antioxidants, but there is scarce knowledge about their effects on suppressing fat accumulation. Here, we investigated the compounds present in yerba mate extracts and assessed their effects on Drosophila melanogaster given a high cholesterol diet. LS-ESI-MS analysis showed the presence of matesaponins, phenolic compounds and methylxanthines in all of the examined extracts. In Drosophila, under extract treatment conditions, the mean lifespan was significantly extended from 38 to 43 days, there was an increase in the ability to support induced stress and decrease in lipid peroxidation products. Moreover, yerba mate extracts recovered the glutathione S-transferases (GST) activity and reduced the cholesterol level. Taken together, our results support that extracts can extend lifespan by reducing the detrimental effect of a high-fat diet in D. melanogaster, and this outcome can be associated with the compound content in the extracts. This study improves the understanding of natural interventions that reduce stress-induced oxidative damage, which is fundamental in promoting healthy ageing.


Assuntos
Antioxidantes/farmacologia , Drosophila melanogaster/fisiologia , Ilex paraguariensis/química , Longevidade/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Dieta Hiperlipídica , Drosophila melanogaster/crescimento & desenvolvimento , Longevidade/fisiologia , Estresse Oxidativo/fisiologia
13.
Environ Monit Assess ; 189(10): 511, 2017 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-28924917

RESUMO

Mangrove forests play an important role in biogeochemical cycles of metals, nutrients, and C in coastal ecosystems. However, these functions could be strongly affected by the mangrove soil degradation. In this study, we performed an intensive sampling characterizing mangrove soils under different types of environment (lagoon/gulf) and vegetation (Rhizophora/Avicennia/dead mangrove) in the Venezuelan coast. To better understand the spatial heterogeneity of the composition and characteristics of the soils, a wide range of the soil attributes were analyzed. In general, the soils were anoxic (Eh < 200 mV), with a neutral pH and low concentration in toxic metals; nevertheless, they varied widely in the soil and its quality-defining parameters (e.g., clay contents, total organic carbon, Fe, Al, toxic trace metals). It is noteworthy that the mangroves presented a low FePyrite content due to a limitation in the Fe oxyhydroxide contents, especially in soils with higher organic C content (TOC > 15%). Finally, the dead mangrove showed significantly lower amounts of TOC and fibers (in comparison to the well-preserved mangrove forest), which indicates that the C pools in mangrove soils are highly sensitive also to natural impact, such as ENSO.


Assuntos
Avicennia/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Florestas , Rhizophoraceae/crescimento & desenvolvimento , Solo , Áreas Alagadas , Avicennia/química , Metais/análise , Rhizophoraceae/química , Solo/química , Solo/normas , Oligoelementos/análise , Venezuela
14.
Biomedica ; 37(4): 498-506, 2017 Dec 01.
Artigo em Espanhol | MEDLINE | ID: mdl-29373770

RESUMO

INTRODUCTION: Respiratory diseases resulting from exposure to particulate matter such as in coal mining remains a research challenge in this country and a public health issue. Spirometry is a basic test of fundamental respiratory function for the diagnosis and monitoring of these types of chronic lung diseases. OBJECTIVE: To determine spirometric values in the coal mining municipality of Paipa and their association with age and occupational exposure times. MATERIALS AND METHODS: We conducted a descriptive cross-sectional study. The occupational respiratory disease questionnaire of the American Thoracic Society (ATS) was completed while spirometric measurements were performed and interpreted in accordance with international recommendations for conducting the test. RESULTS: The sample consisted of 226 coal mining workers of the municipality of Paipa. Twenty-eight subjects (12.3%) of the sample showed patterns of obstructive and restrictive respiratory disease with mild degrees of severity. Eighty subjects (35%) showed a decrease in the forced vital capacity ratio/expiratory volume in one second (FVC/FEV1). A statistically significant association between age range (p=0.002) and years of mining work (p=0.34) with the development of restrictive and obstructive disorders was found. Also, there was a statistically significant association between age range (p<0.01) and years of mining work (p<0.01) with various degrees of severity of the spirometric pattern. CONCLUSIONS: Spirometry is a useful test for detecting the presence of respiratory disorders in the population of coal miners. The time of exposure was significantly associated with the respiratory disease exhibited by these miners.


Assuntos
Minas de Carvão , Doenças Profissionais/fisiopatologia , Transtornos Respiratórios/fisiopatologia , Espirometria , Adulto , Fatores Etários , Colômbia/epidemiologia , Tosse/diagnóstico , Tosse/epidemiologia , Tosse/fisiopatologia , Estudos Transversais , Dispneia/diagnóstico , Dispneia/epidemiologia , Dispneia/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/diagnóstico , Doenças Profissionais/epidemiologia , Exposição Ocupacional , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Transtornos Respiratórios/diagnóstico , Transtornos Respiratórios/epidemiologia , Índice de Gravidade de Doença , Fumar/epidemiologia , Inquéritos e Questionários
15.
Braz J Med Biol Res ; 49(8)2016 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-27409335

RESUMO

Sida tuberculata (Malvaceae) is a medicinal plant traditionally used in Brazil as an antimicrobial and anti-inflammatory agent. Here, we aimed to investigate the different extractive techniques on phytochemical parameters, as well as to evaluate the toxicity and antioxidant capacity of S. tuberculata extracts using in silico and in vitro models. Therefore, in order to determine the dry residue content and the main compound 20-hydroxyecdysone (20E) concentration, extracts from leaves and roots were prepared testing ethanol and water in different proportions. Extracts were then assessed by Artemia salina lethality test, and toxicity prediction of 20E was estimated. Antioxidant activity was performed by DPPH and ABTS radical scavenger assays, ferric reducing power assay, nitrogen derivative scavenger, deoxyribose degradation, and TBARS assays. HPLC evaluation detected 20E as main compound in leaves and roots. Percolation method showed the highest concentrations of 20E (0.134 and 0.096 mg/mL of extract for leaves and roots, respectively). All crude extracts presented low toxic potential on A. salina (LD50 >1000 µg/mL). The computational evaluation of 20E showed a low toxicity prediction. For in vitro antioxidant tests, hydroethanolic extracts of leaves were most effective compared to roots. In addition, hydroethanolic extracts presented a higher IC50 antioxidant than aqueous extracts. TBARS formation was prevented by leaves hydroethanolic extract from 0.015 and 0.03 mg/mL and for roots from 0.03 and 0.3 mg/mL on egg yolk and rat tissue, respectively (P<0.05). These findings suggest that S. tuberculata extracts are a considerable source of ecdysteroids and possesses a significant antioxidant property with low toxic potential.


Assuntos
Antioxidantes/química , Malvaceae/química , Extratos Vegetais/química , Animais , Antioxidantes/toxicidade , Cromatografia Líquida de Alta Pressão/métodos , Simulação por Computador , Ecdisterona/toxicidade , Masculino , Malvaceae/toxicidade , Extratos Vegetais/toxicidade , Folhas de Planta/química , Raízes de Plantas/química , Ratos Wistar , Testes de Toxicidade
16.
Nano Lett ; 16(4): 2363-8, 2016 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-26998817

RESUMO

Resonant Raman spectroscopy is a powerful tool for providing information about excitons and exciton-phonon coupling in two-dimensional materials. We present here resonant Raman experiments of single-layered WS2 and WSe2 using more than 25 laser lines. The Raman excitation profiles of both materials show unexpected differences. All Raman features of WS2 monolayers are enhanced by the first-optical excitations (with an asymmetric response for the spin-orbit related XA and XB excitons), whereas Raman bands of WSe2 are not enhanced at XA/B energies. Such an intriguing phenomenon is addressed by DFT calculations and by solving the Bethe-Salpeter equation. These two materials are very similar. They prefer the same crystal arrangement, and their electronic structure is akin, with comparable spin-orbit coupling. However, we reveal that WS2 and WSe2 exhibit quite different exciton-phonon interactions. In this sense, we demonstrate that the interaction between XC and XA excitons with phonons explains the different Raman responses of WS2 and WSe2, and the absence of Raman enhancement for the WSe2 modes at XA/B energies. These results reveal unusual exciton-phonon interactions and open new avenues for understanding the two-dimensional materials physics, where weak interactions play a key role coupling different degrees of freedom (spin, optic, and electronic).

17.
J Insect Physiol ; 84: 128-136, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26654885

RESUMO

Ecosystem engineering by insect herbivores occurs as the result of structural modification of plants manipulated by insects. However, only few studies have evaluated the effect of these modifications on the plant responses induced by stem-borers that act as ecosystem engineers. In this study, we evaluated the responses induced by the herbivory of the twig-girdler beetle Oncideres albomarginata chamela (Cerambycidae: Lamiinae) on its host plant Spondias purpurea (Anacardiaceae), and its relationship with the ecosystem engineering process carried out by this stem-borer. Our results demonstrated that O. albomarginata chamela branch removal induced the development of lateral branches increasing the resources needed for the development of future insect generations, of its own offspring and of many other insect species. Detached branches represent habitats with high content of nitrogen and phosphorous, which eventually can be incorporated into the ecosystem, increasing nutrient cycling efficiency. Consequently, branch removal and the subsequent plant tissue regeneration induced by O. albomarginata chamela represent key mechanisms underlying the ecosystem engineering process carried out by this stem-borer, which enhances arthropod diversity in the ecosystem.


Assuntos
Anacardiaceae/parasitologia , Besouros/fisiologia , Animais , Ecossistema , Herbivoria , Interações Hospedeiro-Parasita , Caules de Planta/parasitologia
19.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;49(8): e5282, 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-787378

RESUMO

Sida tuberculata (Malvaceae) is a medicinal plant traditionally used in Brazil as an antimicrobial and anti-inflammatory agent. Here, we aimed to investigate the different extractive techniques on phytochemical parameters, as well as to evaluate the toxicity and antioxidant capacity of S. tuberculata extracts using in silico and in vitro models. Therefore, in order to determine the dry residue content and the main compound 20-hydroxyecdysone (20E) concentration, extracts from leaves and roots were prepared testing ethanol and water in different proportions. Extracts were then assessed by Artemia salina lethality test, and toxicity prediction of 20E was estimated. Antioxidant activity was performed by DPPH and ABTS radical scavenger assays, ferric reducing power assay, nitrogen derivative scavenger, deoxyribose degradation, and TBARS assays. HPLC evaluation detected 20E as main compound in leaves and roots. Percolation method showed the highest concentrations of 20E (0.134 and 0.096 mg/mL of extract for leaves and roots, respectively). All crude extracts presented low toxic potential on A. salina (LD50 >1000 µg/mL). The computational evaluation of 20E showed a low toxicity prediction. For in vitro antioxidant tests, hydroethanolic extracts of leaves were most effective compared to roots. In addition, hydroethanolic extracts presented a higher IC50 antioxidant than aqueous extracts. TBARS formation was prevented by leaves hydroethanolic extract from 0.015 and 0.03 mg/mL and for roots from 0.03 and 0.3 mg/mL on egg yolk and rat tissue, respectively (P<0.05). These findings suggest that S. tuberculata extracts are a considerable source of ecdysteroids and possesses a significant antioxidant property with low toxic potential.


Assuntos
Animais , Masculino , Extratos Vegetais/química , Malvaceae/química , Antioxidantes/química , Simulação por Computador , Extratos Vegetais/toxicidade , Cromatografia Líquida de Alta Pressão/métodos , Ratos Wistar , Testes de Toxicidade , Raízes de Plantas/química , Folhas de Planta/química , Malvaceae/toxicidade , Ecdisterona/toxicidade , Antioxidantes/toxicidade
20.
Open Vet J ; 5(2): 138-47, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26623380

RESUMO

In this study we demonstrated that the vaccine candidate against avian influenza virus H5N1 based on the hemagglutinin H5 (HA) fused to the chicken CD154 (HACD) can also be used for differentiating infected from vaccinated animals (DIVA). As the strategy of DIVA requires at least two proteins, we obtained a variant of the nucleoprotein (NP49-375) in E. coli. After its purification by IMAC, the competence of the proteins NP49-375 and HACD as coating antigens in indirect ELISA assays were tested by using the sera of chickens immunized with the proteins HA and HACD and the reference sera from several avian influenza subtypes. Together with these sera, the sera from different species of birds and the sera of chickens infected with other avian viral diseases were analyzed by competition ELISA assays coated with the proteins NP49-375 and HACD. The results showed that the segment CD154 in the chimeric protein HACD did not interfere with the recognition of the molecule HA by its specific antibodies. Also, we observed variable detection levels when the reference sera were analyzed in the ELISA plates coated with the protein NP49-375. Moreover, only the antibodies of the reference serum subtype H5 were detected in the ELISA plates coated with the protein HACD. The competition ELISA assays showed percentages of inhibition of 88-91% for the positives sera and less than 20% for the negative sera. We fixed the cut-off value of these assays at 25%. No antibody detection was observed in the sera from different species of birds or the sera of chickens infected with other avian viral diseases. This study supported the fact that the ELISA assays using the proteins NP49-375 and HACD could be valuable tools for avian influenza surveillance and as a strategy of DIVA for counteracting the highly pathogenic avian influenza virus H5N1 outbreaks.

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