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1.
Rev Sci Instrum ; 93(10): 103506, 2022 Oct 01.
Article in English | MEDLINE | ID: mdl-36319395

ABSTRACT

Plastic deformation of samples compressed to Mbar pressures at high strain rates at the National Ignition Facility (NIF) forms the basis of ongoing material strength experiments in conditions relevant to meteor impacts, geophysics, armor development, and inertial confinement fusion. Hard x-ray radiography is the primary means of measuring the evolution of these samples, typically employing a slit-collimated high-Z microdot driven by the NIF laser to generate >40 keV x rays [E. Gumbrell et al., Rev. Sci. Instrum. 89, 10G118 (2018) and C. M. Huntington et al., Rev. Sci. Instrum. 89, 10G121 (2018)]. Alternatively, a dysprosium "micro-flag" target driven by the Advanced Radiographic Capability laser (∼2 kJ, 10 ps) can deliver significantly higher spatiotemporal resolution [M. P. Hill et al., Rev. Sci. Instrum. 92, 033535 (2021)], especially in high-opacity samples. Initial experiments revealed problematic brightness and spectral gradients from this source, but by radiographing a set of diamond-turned, 105 µm-thick Pb test objects and supported by simulations using the 3D Monte Carlo code GEANT4, these geometry-dependent gradients across the field of view are quantified and mitigation strategies are assessed. In addition to significantly enhancing the modulation transfer function compared to the existing system, image stacking from multiple layers of image plate is shown to almost double the signal to noise ratio that will reduce uncertainties in future dynamic strength experiments.

2.
Neotrop Entomol ; 48(6): 983-991, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31823153

ABSTRACT

Aphidius colemani (Viereck) was reported in Brazil before the Biological Control Program of Wheat Aphids (BCPWA) when Mediterranean genotypes were introduced from France and Israel. This species was re-described as a complex called A. colemani group composed of three species. Consequently, uncertainty remains about which parasitoid of the group is occurring in southern Brazil. This study has two main objectives: (i) re-examine the species status of A. colemani group collected during the introduction of parasitoids and from a 10-year (2009-2018) monitoring program in wheat fields in northern Rio Grande do Sul (RS), Brazil; (ii) describe the variation in the population density of parasitoids and its association with meteorological factors during this period. We examined 116 specimens from the Embrapa Wheat entomological collection, and those collected in Moericke traps in Coxilha, RS. All the parasitoids of the A. colemani group from the BCPWA period were identified as Aphidius platensis (Brèthes). In traps, 6541 cereal aphid parasitoids were collected, of which 61.9% (n = 4047) were from A. colemani group and all those were identified as A. platensis. Temperature was the factor that effected population density with the highest number of parasitoids recorded in the winter months. Sex ratio changed between years varying from 0.50 to 0.97. The parasitoid A. platensis was the only species in the A. colemani group sampled during 10 years of monitoring.


Subject(s)
Aphids/parasitology , Biological Control Agents , Wasps/classification , Wasps/growth & development , Animals , Brazil , Female , Male , Pest Control, Biological , Population Density , Seasons , Sex Ratio , Temperature , Triticum , Wasps/anatomy & histology , Wings, Animal/anatomy & histology
3.
Genet Mol Res ; 12(3): 3128-35, 2013 Feb 28.
Article in English | MEDLINE | ID: mdl-23479168

ABSTRACT

Ricinus communis (castor bean) seeds are used to produce an alcohol-soluble oil that is used in more than 400 industrial processes. Despite its economic importance, there has been little research on the endophytic microbiota of castor bean seeds. This microbiota is important for plant metabolic processes and may have considerable biotechnological potential, such as production of lipases and plant growth promoter agents. We evaluated several DNA extraction methodologies in order to access the microbial diversity of castor bean through a metagenomic approach. Based on our observations, we developed a new methodology that takes advantage of the low solubility of calcium phosphates and the high affinity of these phosphates for proteins and polysaccharides. The extracted DNA quality was evaluated by PCR, using a selective primer pair for bacterial and mitochondrial 16S rDNA genes (799F and 1492R). We found this methodology quantitatively and qualitatively more efficient than the other approaches. In evaluating this new extraction methodology, we found that the difficulties of DNA extraction from castor bean seeds, such as abundant oil, polysaccharides, phenolic compounds, and plant enzymes, could be overcome. The resulting extracts had high concentration and purity, and they were obtained faster than with previous methods. The samples contained virtually all of the DNA, including the microbial DNA; this was validated by PCR analysis.


Subject(s)
Bacteria/genetics , Microbiota/genetics , RNA, Ribosomal, 16S/genetics , Ricinus/microbiology , Bacteria/classification , Castor Oil , DNA, Bacterial/classification , DNA, Bacterial/genetics , Genetic Variation , Metagenomics , Ricinus/genetics , Seeds/genetics , Seeds/microbiology
4.
Neotrop Entomol ; 41(6): 503-9, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23949676

ABSTRACT

Plant extracts represent a great source of molecules, with insecticidal activity, which are used for pest control in several crop production systems. This work aimed to evaluate the toxicity of an aqueous extract of leaves of castor bean against larvae of Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) in search for different classes of molecules with insecticidal activities by using in vitro assays. The effects of the castor bean leaf extract on the food utilization, development, and survival of S. frugiperda larvae was evaluated by feeding the larvae an artificial diet supplemented with different concentrations of the extract (0%, 1%, 2.5%, 5%, and 10% w/v). The effects observed were dose-dependent, and the highest concentration evaluated (10% w/v) was the one the most affected food utilization by altering the nutritional indices, as well as larval weight gain, development time, and survivorship. In vitro assays to detect saponins, lectins, and trypsin inhibitors in the castor bean leaf extract were performed, but only trypsin inhibitors were detected. No preference for the diet source was detected in S. frugiperda by feeding the larvae in choice experiments with diets containing different concentrations of the castor bean extract tested. The data obtained indicate the existence of a potential molecule in the tested extract of castor bean to be used as an alternative insecticide to be integrated in the management of S. frugiperda.


Subject(s)
Insecticides , Lepidoptera/drug effects , Lepidoptera/physiology , Plant Extracts/analysis , Plant Extracts/pharmacology , Ricinus communis , Animals , Plant Leaves
5.
Rev. bras. plantas med ; 14(4): 643-648, 2012. tab
Article in Portuguese | LILACS | ID: lil-664016

ABSTRACT

A prevalência da obesidade está aumentando a um ritmo alarmante e poucos medicamentos para o tratamento estão atualmente disponíveis no mercado. A inibição da lipase pancreática é um dos mecanismos mais amplamente estudados para determinar a eficácia de produtos naturais como agentes antiobesidade. O objetivo do estudo foi avaliar in vitro a inibição de dezenove extratos aquosos e metanólicos sobre a lipase pancreática. Ensaios cinéticos foram realizados em quatro períodos de tempo com ausência e presença do extrato inibidor. Também foi avaliado a ação desses extratos após a simulação do fluido gástrico. Cymbopogon citratus apresentou a maior inibição, seguido de Costus spicatus e Baccharis trimera. Os extratos apresentam um potencial como adjuvante no tratamento da obesidade.


The prevalence of obesity has been increasing at an alarming rate and only a few medications are currently available in the market. Pancreatic lipase inhibition is one of the most widely studied mechanisms for determining the efficacy of natural products as anti-obesity agents. The aim of this study was to evaluate in vitro the inhibition of nineteen aqueous and methanol extracts on pancreatic lipase. Kinetic assays were performed in four periods with the absence and the presence of the inhibitor extract. We also tested the action of these extracts after gastric fluid simulation. Cymbopogon citratus showed the highest inhibition, followed by Costus spicatus and Baccharis trimera. The extracts have the potential to act as adjuvants in the treatment of obesity.


Subject(s)
Plant Extracts/analysis , Anti-Obesity Agents/analysis , Lipids , Obesity/drug therapy
6.
Rev. bras. plantas med ; 12(4): 516-518, out.-dez. 2010. tab
Article in Portuguese | LILACS | ID: lil-578995

ABSTRACT

Várias plantas têm sido consideradas produtos terapêuticos, dentre elas destacam-se os chás verde e preto, popularmente utilizados para controle da hiperglicemia e obesidade. Objetivou-se neste trabalho avaliar o potencial inibitório sobre as enzimas α-amilase, α e β-glicosidases e o teor de compostos fenólicos do chá verde e do chá preto. O teor de compostos fenólicos encontrados foram de 80,8 ± 0,43 mg g-1 no chá preto e 32,0 ± 0,12 mg g-1 no chá verde. O chá verde e o chá preto, em condições de consumo, inibiram as enzimas em estudo, porém, após a simulação do fluido gástrico o inibidor presente no chá verde perdeu a ação. O chá preto deixou de inibir a α-amilase e apresentou inibição inalterada para α e β-glicosidases. Tais resultados sugerem que o chá preto pode ser auxiliar em dietas de restrição de carboidratos.


Several plants have been considered therapeutic products, including green and black tea, popularly used to control hyperglycemia and obesity. This study aimed to evaluate the inhibitory potential of the enzymes α-amylase, α and β-glycosidases, as well as the content of phenolic compounds in green tea and black tea. The concentrations of phenolic compounds found were 80.8 ± 0.43 mg g-1 in black tea and 32.0 ± 0.12 mg g-1 in green tea. Under the tested conditions of use, green and black tea inhibited the enzyme under study. However, after simulation of the gastric fluid, the inhibitor present in green tea lost its action. Black tea no longer inhibited a-amylase and showed unaltered inhibition for α and β-glycosidases. These results suggest that black tea can be helpful in diets restricting carbohydrates.


Subject(s)
Camellia sinensis/physiology , Glycoside Hydrolases/analysis , In Vitro Techniques , Enzymes/metabolism , Hyperglycemia , Obesity
7.
Parasite Immunol ; 32(4): 245-51, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20398224

ABSTRACT

The aim of this study was to evaluate a possible synergism between melatonin and meloxicam in up-regulating the immune response in male Wistar rats infected with Trypanosoma cruzi during immunosuppression phenomenon, which characterizes the acute phase of the Chagas' disease. Male Wistar rats were infected with the Y strain of T. cruzi. Experiments were performed on 7, 14 and 21 days post-infection. Several immunological parameters were evaluated including gamma-interferon (IFN-gamma), interleukin-2 (IL-2), nitric oxide (NO) and prostaglandin E(2) (PGE(2)). The combined treatment with melatonin and meloxicam significantly enhanced the release of IL-2 and INF-gamma into animals' serum, when compared with the infected control groups during the course of infection. Furthermore, the blockade of PGE(2) synthesis and the increased release of NO by macrophage cells from T. cruzi-infected animals contributed to regulate the production of Th1 subset cytokines significantly reducing the parasitaemia in animals treated with the combination of both substances. Therefore, our results suggest that the association of melatonin and meloxicam was more effective in protecting animals against the harmful actions of T. cruzi infection as compared with the treatments of meloxicam or melatonin alone.


Subject(s)
Chagas Disease/drug therapy , Chagas Disease/immunology , Immunologic Factors/therapeutic use , Melatonin/therapeutic use , Thiazines/therapeutic use , Thiazoles/therapeutic use , Trypanosoma cruzi/immunology , Animals , Dinoprostone/metabolism , Drug Synergism , Interferon-gamma/blood , Interleukin-2/blood , Macrophages/metabolism , Male , Meloxicam , Nitric Oxide/metabolism , Rats , Rats, Wistar
8.
Rev Neurol ; 48(6): 304-10, 2009.
Article in Spanish | MEDLINE | ID: mdl-19291655

ABSTRACT

INTRODUCTION: Acute neurodegenerative diseases, including stroke and traumatic brain and spinal cord injury, possess an elevated worldwide incidence. Two distinct lesive patterns can be identified after these destructive events: primary damage, an early consequence of the primary pathological event, and secondary neural degeneration (SND), a group of pathological events inducing late degeneration in cells not or even only partially affected by the primary damage. This pathological mechanism is an important contributing factor for functional deficits and target for therapeutic approaches. Several factors are involved on the SND etiology, including excitotoxicity, inflammation, and oxidative stress. AIM: To review the main mechanisms underlying the SND occurring after acute neural disorders. DEVELOPMENT: The more recent findings about the eliciting processes of SND degeneration are discussed, as well as their significance to degeneration of white matter tracts. CONCLUSIONS: The characterization of the events underlying SND is of fundamental importance for the development of new therapeutic approaches effective enough to decrease the functional deficits, contributing to the improvement of the quality of life of people suffering neurological diseases. These therapeutic approaches must be validated in experimental models of both brain and spinal cord diseases, which effectively simulate human neural disorders protecting both gray and white matters for a better neuroprotective efficacy.


Subject(s)
Central Nervous System , Nerve Degeneration/pathology , Nerve Degeneration/physiopathology , Neurodegenerative Diseases/pathology , Neurodegenerative Diseases/physiopathology , Central Nervous System/anatomy & histology , Central Nervous System/pathology , Glutamic Acid/metabolism , Humans , Inflammation/pathology , Inflammation/physiopathology , Nerve Degeneration/etiology , Neurodegenerative Diseases/complications , Neurodegenerative Diseases/epidemiology , Oxidative Stress
9.
Brain Res ; 1200: 78-88, 2008 Mar 20.
Article in English | MEDLINE | ID: mdl-18289508

ABSTRACT

Following acute and chronic neurodegenerative disorders, a cascade of pathological events including inflammatory response, excitotoxicity and oxidative stress induces secondary tissue loss in both gray and white matter. Axonal damage and demyelination are important components of the white matter demise during these diseases. In spite of this, a few studies have addressed the patterns of inflammatory response, axonal damage and demyelination following focal ischemic damage to the central nervous system (CNS). In the present study, we describe the patterns of inflammatory response, axonal damage and myelin impairment following microinjections of 10 pmol of endothelin-1 into the rat striatum. Animals were perfused at 1 day, 3 days and 7 days after injection. 20 mum sections were stained by hematoxylin and immunolabeled for neutrophils (anti-MBS-1), activated macrophages/microglia (anti-ED1), damaged axons (anti-betaAPP) and myelin (anti-MBP). The evolution of acute inflammation was quantitatively assessed by cell counts in different survival times. There was recruitment of both neutrophils and macrophages to the damaged striatal parenchyma with maximum recruitment at 1 day and 7 days, respectively. Progressive myelin impairment in the striatal white matter tracts has been observed mainly at later survival times. beta-APP+ endbulbs were not present in all evaluated time points. These results suggest that progress myelin impairment in the absence of damage to axonal cylinder is a feature of white matter pathology following endothelin-1-induced focal striatal ischemia.


Subject(s)
Brain Ischemia/physiopathology , Corpus Striatum/physiopathology , Demyelinating Diseases/physiopathology , Encephalitis/physiopathology , Endothelin-1/toxicity , Nerve Fibers, Myelinated/pathology , Amyloid beta-Peptides/analysis , Amyloid beta-Peptides/metabolism , Animals , Axons/drug effects , Axons/metabolism , Axons/pathology , Biomarkers/analysis , Biomarkers/metabolism , Brain Ischemia/chemically induced , Brain Ischemia/pathology , Cerebral Arteries/drug effects , Cerebral Arteries/metabolism , Cerebral Arteries/physiopathology , Chemotaxis, Leukocyte/drug effects , Chemotaxis, Leukocyte/physiology , Corpus Striatum/drug effects , Corpus Striatum/pathology , Demyelinating Diseases/chemically induced , Demyelinating Diseases/pathology , Disease Progression , Encephalitis/chemically induced , Encephalitis/pathology , Male , Microcirculation/drug effects , Microcirculation/metabolism , Microcirculation/physiopathology , Microglia/drug effects , Microglia/metabolism , Microinjections , Myelin Basic Protein/analysis , Myelin Basic Protein/metabolism , Nerve Fibers, Myelinated/drug effects , Nerve Fibers, Myelinated/metabolism , Neutrophils/drug effects , Neutrophils/metabolism , Rats , Rats, Wistar
10.
Brain Res ; 1172: 130-44, 2007 Oct 03.
Article in English | MEDLINE | ID: mdl-17822682

ABSTRACT

Inflammatory response, axonal damage and demyelination are important components of the pathophysiology of acute neurodegenerative diseases. We have investigated the outcome of these pathological events following an excitotoxic or an ischemic damage to the spinal nucleus of adult rats at 1 and 7 days postinjury. Microinjections of 80 nmol of NMDA or 40 pmol of endothelin-1 into the rat spinal nucleus induced differential histopathological events. NMDA injection induced intense tissue loss in the gray matter (GM) without significant tissue loss in the white matter (WM). There was a mild inflammatory response, with recruitment of a few neutrophils and macrophages. Axonal damage was present in the GM following NMDA injection, with negligible axonal damage in the WM. Myelin impairment was apparent at 7 days. Microinjections of endothelin-1 into the same region induced lesser tissue loss than NMDA injections, concomitant with an intense inflammatory response characterized by recruitment of macrophages, but not of neutrophils. There were more axonal damage and early myelin impairment after endothelin-1 injection. These results were confirmed by quantitative analysis. Microcysts were present in the WM of the trigeminothalamic tract at 7 days following injection of endothelin-1. These results show that an ischemic damage to the spinal nucleus affects both GM and WM with more bystander inflammation, axonal damage and myelin impairment, while excitotoxic damage induces effects more restricted to the GM. These pathological events may occur following acute damage to the human brain stem and can be an important contributing factor to the underlying functional deficits.


Subject(s)
Axons/pathology , Demyelinating Diseases/pathology , Inflammation/pathology , Trigeminal Nucleus, Spinal/pathology , Amyloid beta-Protein Precursor/metabolism , Analysis of Variance , Animals , Brain Ischemia/complications , Cell Count , Demyelinating Diseases/etiology , Ectodysplasins/metabolism , Endothelin-1/toxicity , Inflammation/chemically induced , Inflammation/etiology , Male , Myelin Basic Protein/metabolism , N-Methylaspartate/toxicity , Neurotoxins/toxicity , Rats , Rats, Wistar , Time Factors , Trigeminal Nucleus, Spinal/drug effects
11.
Vet Parasitol ; 143(3-4): 222-8, 2007 Feb 28.
Article in English | MEDLINE | ID: mdl-17081692

ABSTRACT

The aim of this study was to investigate the influences of ovariectomy on histopathological and hematological parameters during the course of Trypanosoma cruzi infection. Hematological and immunological homeostasis is influenced by gonadal steroid hormones. Ovariectomy exerts profound influences on parasitic diseases including T. cruzi infection through modulation of the host's immune response. Three groups of female Mus musculus were infected with 4000 blood trypomastigotes of the Y strain of T. cruzi. One group was subjected to ovariectomy, another to simulated surgery before the infection, and a third group of unoperated animals were used as controls. Marked differences were detected in the responses of blood and tissue parasites. On day 9, post-infection parasitism was significantly higher in ovariectomized animals (P<0.05). These results were confirmed by histopathological studies, in which ovariectomized animals displayed hearts with higher number of amastigote burdens, increased inflammatory infiltrate, enhanced tissue fibers disorganization and decreased lytic antibody percentage, when compared to their counterparts. On day 9 the hematological changes were more apparent, with a decrease in erythrocytes, platelets and leucocytes for ovariectomized infected animals. Simulated surgery, as a stressful agent, did not cause any imbalance in parasitism or in the hemogram profile. The results confirm the importance of the female steroids in resistance against T. cruzi infection.


Subject(s)
Chagas Disease/blood , Chagas Disease/pathology , Ovariectomy , Trypanosoma cruzi/pathogenicity , Analysis of Variance , Animals , Chagas Disease/immunology , Chagas Disease/parasitology , Disease Models, Animal , Female , Heart/parasitology , Humans , Mice , Myocardium/pathology , Ovariectomy/veterinary , Parasitemia/epidemiology , Parasitemia/immunology , Parasitemia/pathology , Random Allocation , Time Factors
12.
J Virol ; 74(1): 564-72, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10590151

ABSTRACT

We report that endoplasmic reticulum alpha-glucosidase inhibitors have antiviral effects on dengue (DEN) virus. We found that glucosidase inhibition strongly affects productive folding pathways of the envelope glycoproteins prM (the intracellular glycosylated precursor of M [membrane protein]) and E (envelope protein): the proper folding of prM bearing unprocessed N-linked oligosaccharide is inefficient, and this causes delayed formation of prME heterodimer. The complexes formed between incompletely folded prM and E appear to be unstable, leading to a nonproductive pathway. Inhibition of alpha-glucosidase-mediated N-linked oligosaccharide trimming may thus prevent the assembly of DEN virus by affecting the early stages of envelope glycoprotein processing.


Subject(s)
Dengue Virus/drug effects , Endoplasmic Reticulum/virology , Enzyme Inhibitors/pharmacology , Virion/growth & development , Virus Replication/drug effects , alpha-Glucosidases/pharmacology , 1-Deoxynojirimycin/pharmacology , Amino Acid Sequence , Animals , Dengue/virology , Dengue Virus/physiology , Indolizines/pharmacology , Mice , Molecular Sequence Data , Protein Processing, Post-Translational , Viral Structural Proteins/chemistry , Viral Structural Proteins/metabolism
13.
Int J Parasitol ; 26(5): 509-10, 1996 May.
Article in English | MEDLINE | ID: mdl-8818730

ABSTRACT

Harposporium anguillulae is a common nematophagous fungus which colonizes cattle pats deposited in Brachiaria decumbens pasture in Brazil. To assess its possible effect on free living stages of trichostrongylid nematodes, the reduction of Haemonchus contortus infective stages in sheep faecal culture was evaluated in vitro. Addition of 300,000 conidia per gram of faeces caused a reduction of 99.5% compared to the control group. This result indicates that H. anguillulae could be a candidate for the development of strategies for the biological control of trichostrongylid nematodes.


Subject(s)
Feces/parasitology , Haemonchus/isolation & purification , Haemonchus/microbiology , Mitosporic Fungi/pathogenicity , Sheep/parasitology , Animals , Cattle , Haemonchiasis/prevention & control , Haemonchiasis/veterinary , Haemonchus/pathogenicity , Pest Control, Biological , Sheep Diseases/prevention & control
14.
Bol. psiquiatr ; 17(2): 57-67, 1984.
Article in Portuguese | LILACS | ID: lil-22119

ABSTRACT

Na etapa inicial desta pesquisa, os autores compararam a analise de uma instituicao nao-escolar para criancas de seis a catorze anos com os resultados de duas aplicacoes da prova de Rorschach com intervalo de um ano. Neste intervalo detectaram a evasao de quarenta das setenta criancas da amostragem inicial. Na presente etapa, propoem a pesquisa dos fatores que ponderam esse fenomeno. Apresentam os dados obtidos junto as familias da populacao evadida (que se mostram possiveis de explicar o fenomeno) bem como discutem aplicacao da prova de Rorschach junto as criancas desta segunda populacao


Subject(s)
Child , Adolescent , Humans , Child, Institutionalized , Personality Development , Rorschach Test , Family
15.
Bol. psiquiatr ; 15(2): 81-5, 1982.
Article in Portuguese | LILACS | ID: lil-7723

ABSTRACT

Estudo preliminar realizado por uma equipe multidisciplinar do Setor de Psiquiatria Social da Escola Paulista de Medicina, com base na observacao participante de um grupo de familias migrantes nordestinas com ocorrencia de quadros psiquiatricos. Atraves de analise de alguns casos foi possivel supor que certas condutas, alem de "desviantes", seriam tambem respostas adequadas a situacoes concretas.Levanta-se a hipotese de que e preciso analisar as perturbacoes psiquicas desta populacao no contexto das correntes migratorias internas brasileiras, vinculando o que, na maioria das vezes, e visto exclusivamente do ponto de vista do individuo com processos sociais e culturais mais amplos


Subject(s)
Humans , Mental Disorders , Transients and Migrants
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