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1.
ACS Omega ; 9(27): 29516-29528, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-39005809

RESUMO

A heterogenized Mn(III) porphyrin-based catalyst was prepared for dye degradation. The new Mn(III) complex of 5,15-bis(4-aminophenyl)-10,20-diphenylporphyrin was immobilized, via covalent bond, in chloropropyl silica gel, generating the material (Sil-Cl@MnP) with a loading of 23 µmol manganese porphyrin (MnP) per gram of Sil-Cl. This material was used as a catalyst in degradation reactions of model dyes, a cationic dye [methylene blue (MB)] and an anionic dye (reactive red 120, RR120), using PhI(OAc)2 and H2O2 as oxidants. The oxidation reactions were carried out after the dye reached adsorption/desorption equilibrium with the catalytic material, with a much higher percentage of adsorption being observed for the cationic MB dye (20%) than for the anionic RR120 dye (3%), which may be associated with electrostatic attraction or repulsion effects, respectively, with the negatively charged surface of the silica (zeta potential measurement for Sil-Cl@MnP, ζ = -19.2 mV). In general, there was a higher degradation percentage for MB than for RR120, probably because the size and charge of RR120 would hinder its approach to the MnP active species on the silica surface. With respect to the oxidant, the PhI(OAc)2-based systems showed a higher degradation percentage than those of H2O2. It was observed that the increase in the oxidant concentration promoted a significant increase in the degradation of MB, with a degradation of approximately 65%. The efficiency of the catalyst was also evaluated after successive additions of the oxidant every 2 h, and it can be seen that the catalyst had no loss of efficiency, with a degradation percentage greater than 80% being observed after 8 h of reaction. The phytotoxicity of the products formed in the system was evaluated in a 1:23.5:188 molar ratio Sil-Cl@MnP: MB:PhI(OAc)2 was used. In these studies, phytotoxicity was found for the germination of lettuce seeds when the original solution was used without dilution; however, when diluted (10% V/V), the results were close to the positive and negative controls. Thus, the material obtained proved to be a potential candidate for application in the degradation reactions of environmental pollutants.

2.
Nature ; 627(8005): 789-796, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38538940

RESUMO

The Antarctic Circumpolar Current (ACC) represents the world's largest ocean-current system and affects global ocean circulation, climate and Antarctic ice-sheet stability1-3. Today, ACC dynamics are controlled by atmospheric forcing, oceanic density gradients and eddy activity4. Whereas palaeoceanographic reconstructions exhibit regional heterogeneity in ACC position and strength over Pleistocene glacial-interglacial cycles5-8, the long-term evolution of the ACC is poorly known. Here we document changes in ACC strength from sediment cores in the Pacific Southern Ocean. We find no linear long-term trend in ACC flow since 5.3 million years ago (Ma), in contrast to global cooling9 and increasing global ice volume10. Instead, we observe a reversal on a million-year timescale, from increasing ACC strength during Pliocene global cooling to a subsequent decrease with further Early Pleistocene cooling. This shift in the ACC regime coincided with a Southern Ocean reconfiguration that altered the sensitivity of the ACC to atmospheric and oceanic forcings11-13. We find ACC strength changes to be closely linked to 400,000-year eccentricity cycles, probably originating from modulation of precessional changes in the South Pacific jet stream linked to tropical Pacific temperature variability14. A persistent link between weaker ACC flow, equatorward-shifted opal deposition and reduced atmospheric CO2 during glacial periods first emerged during the Mid-Pleistocene Transition (MPT). The strongest ACC flow occurred during warmer-than-present intervals of the Plio-Pleistocene, providing evidence of potentially increasing ACC flow with future climate warming.

3.
Biomed Pharmacother ; 173: 116316, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38394853

RESUMO

Ethanol is one of the psychoactive substances most used by young individuals, usually in an intermittent and episodic manner, also called binge drinking. In the adolescent period, brain structures undergo neuromaturation, which increases the vulnerability to psychotropic substances. Our previous studies have revealed that ethanol binge drinking during adolescence elicits neurobehavioral alterations associated with brain damage. Thus, we explored the persistence of motor function impairment and cerebellum damage in the context of ethanol withdrawal periods (emerging adulthood and adult life) in adolescent female rats. Female Wistar rats (35 days old) received orally 4 cycles of ethanol (3.0 g/kg/day) or distilled water in 3 days on-4 days off paradigm (35th until 58th day of life). Motor behavioral tests (open field, grip strength, beam walking, and rotarod tests) and histological assays (Purkinje's cell density and NeuN-positive cells) were assessed on the 1-, 30-, and 60-days of binge alcohol exposure withdrawal. Our findings demonstrate that the adolescent binge drinking exposure paradigm induced cerebellar cell loss in all stages evaluated, measured through the reduction of Purkinje's cell density and granular layer neurons. The cerebellar tissue alterations were accompanied by behavioral impairments. In the early withdrawal, the reduction of spontaneous movement, incoordination, and unbalance was seen. However, the grip strength reduction was found at long-term withdrawal (60 days of abstinence). The cerebellum morphological changes and the motor alterations persisted until adulthood. These data suggest that binge drinking exposure during adolescence causes motor function impairment associated with cerebellum damage, even following a prolonged withdrawal, in adult life.


Assuntos
Alcoolismo , Consumo Excessivo de Bebidas Alcoólicas , Síndrome de Abstinência a Substâncias , Ratos , Animais , Feminino , Ratos Wistar , Etanol/toxicidade , Consumo de Bebidas Alcoólicas , Cerebelo/patologia , Alcoolismo/patologia , Síndrome de Abstinência a Substâncias/patologia , Fatores Etários
4.
Headache ; 63(4): 461-471, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37036168

RESUMO

OBJECTIVE: To review the epidemiology, the differential diagnosis, and the clinical and laboratory factors associated with the care management of headaches in patients with systemic lupus erythematosus (SLE). BACKGROUND: SLE is a chronic autoimmune disease and in 12%-95% of patients, the nervous system is involved. Headache is a frequently reported, although nonspecific, symptom that may potentially represent serious underlying diagnoses. Primary headaches may also occur in these patients, thereby causing a negative and significant impact on their quality of life. METHODS: This is a narrative review. A literature review was conducted on the PubMed platform using the following terms: (1) headache and (2) lupus. All articles considered relevant were included. No limitations were imposed for the publication date. RESULTS: Headache is a frequent symptom in patients with SLE. Although its prevalence is similar to the general population, headaches nonetheless tend to have a greater negative impact on these patients. Patients with SLE are more likely to experience headache due to vascular diseases such as cerebral venous sinus thrombosis, stroke, reversible cerebral vasoconstriction syndrome, posterior reversible encephalopathy syndrome, and vasculitis. Aseptic meningitis, neuroinfections, intracranial neoplasms, and intracranial hypertension or hypotension may also be a cause of headache in these patients. Although used in disease activity scores, the concept of lupus headache is controversial. CONCLUSIONS: Headache is a frequent symptom in patients with SLE. An appropriate approach enables the potentially serious conditions, which are the causes of secondary headaches, to be recognized and treated, together with an appropriate diagnosis and treatment of primary headaches.


Assuntos
Lúpus Eritematoso Sistêmico , Síndrome da Leucoencefalopatia Posterior , Humanos , Qualidade de Vida , Síndrome da Leucoencefalopatia Posterior/complicações , Síndrome da Leucoencefalopatia Posterior/diagnóstico , Cefaleia/epidemiologia , Cefaleia/etiologia , Cefaleia/diagnóstico , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/epidemiologia , Lúpus Eritematoso Sistêmico/diagnóstico , Diagnóstico Diferencial
5.
J Gerontol A Biol Sci Med Sci ; 78(9): 1543-1549, 2023 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-36905160

RESUMO

Osteosarcopenia is a complex geriatric syndrome characterized by the presence of both sarcopenia and osteopenia/osteoporosis. This condition increases rates of disability, falls, fractures, mortality, and mobility impairments in older adults. The purpose of this study was to analyze the Fourier-transform infrared (FTIR) spectroscopy diagnostic power for osteosarcopenia in community-dwelling older women (n = 64; 32 osteosarcopenic and 32 non-osteosarcopenia). FTIR is a fast and reproducible technique highly sensitive to biological tissues, and a mathematical model was created using multivariate classification techniques that denoted the graphic spectra of the molecular groups. Genetic algorithm and support vector machine regression (GA-SVM) was the most feasible model, achieving 80.0% of accuracy. GA-SVM identified 15 wave numbers responsible for class differentiation, in which several amino acids (responsible for the proper activation of the mammalian target of rapamycin) and hydroxyapatite (an inorganic bone component) were observed. Imaging tests and low availability of instruments that allow the observation of osteosarcopenia involve high health costs for patients and restrictive indications. Therefore, FTIR can be used to diagnose osteosarcopenia due to its efficiency and low cost and to enable early detection in geriatric services, contributing to advances in science and technology that are potential "conventional" methods in the future.


Assuntos
Fraturas Ósseas , Osteoporose , Sarcopenia , Humanos , Feminino , Idoso , Vida Independente , Espectroscopia de Infravermelho com Transformada de Fourier , Osteoporose/diagnóstico por imagem , Sarcopenia/diagnóstico
6.
Muscle Nerve ; 67(6): 522-536, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36905197

RESUMO

INTRODUCTION/AIMS: Peripheral nerve injuries result in impaired neuromuscular interactions, leading to morphological and functional alterations. Adjuvant suture repair methods have been used to improve nerve regeneration and modulate the immune response. Heterologous fibrin biopolymer (HFB), a scaffold with adhesive properties, plays a critical role in tissue repair. The aim of this study is to evaluate neuroregeneration and immune response focusing on neuromuscular recovery, using suture-associated HFB for sciatic nerve repair. METHODS: Forty adult male Wistar rats were distributed into four groups (n = 10): C (control), only sciatic nerve location; D (denervated), neurotmesis and 6-mm gap removal and fixation stumps in subcutaneous tissue; S (suture), neurotmesis followed by suture; and SB (suture + HFB), neurotmesis followed by suture and HFB. Analysis of M2 macrophages (CD206+ ), as well as the morphology and morphometry of nerves, soleus muscle, and neuromuscular junctions (NMJs), were performed at 7 and 30 days after surgery. RESULTS: The SB group had the highest M2 macrophage area in both periods. After 7 days, SB was the only group similar to the C group regarding the number of axons; furthermore, after 30 days, the SB group was closer to the C group concerning blood vessel and central myonuclear numbers, NMJ angle, and connective tissue volume. After 7 days, increases in nerve area, as well as the number and area of blood vessels, were also observed in SB. DISCUSSION: HFB potentiates the immune response, increases axonal regeneration, induces angiogenesis, prevents severe muscle degeneration, and assists in NMJ recovery. In conclusion, suture-associated HFB has major implications for improved peripheral nerve repair.


Assuntos
Adesivo Tecidual de Fibrina , Fibrina , Ratos , Animais , Masculino , Adesivo Tecidual de Fibrina/farmacologia , Ratos Wistar , Nervo Isquiático/lesões , Biopolímeros , Regeneração Nervosa , Suturas
7.
Oxid Med Cell Longev ; 2022: 7207755, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36329802

RESUMO

Alcohol consumption is spread worldwide and can lead to an abuse profile associated with severe health problems. Adolescents are more susceptible to addiction and usually consume ethanol in a binge drinking pattern. This form of consumption can lead to cognitive and emotional disorders, however scarce studies have focused on long-term hazardous effects following withdrawal periods after binge drinking in adolescents. Thus, the present study aims at investigating whether behavioral and cognitive changes persist until mid and late adulthood. Female Wistar rats (9-10 animals/group) received intragastric administration of four cycles of ethanol binge-like pattern (3.0 g/kg/day, 20% w/v; 3 days-on/4 days-off) from 35th to 58th days old, followed withdrawal checkpoints 1 day, 30 days, and 60 days. At each checkpoint period, behavioral tests of open field, object recognition test, elevated plus maze, and forced swimming test were performed, and blood and hippocampus were collected for oxidative biochemistry and brain-derived neurotrophic factor (BDNF) levels analysis, respectively. The results demonstrated that adolescent rats exposed to binge drinking displayed anxiogenic- and depressive-like phenotype in early and midadulthood, however, anxiety-like profile persisted until late adulthood. Similarly, short-term memory was impaired in all withdrawal periods analysed, including late adult life. These behavioral data were associated with oxidative damage in midadulthood but not BDNF alterations. Taken together, the present work highlights the long-lasting emotional and cognitive alterations induced by ethanol binge drinking during adolescence, even after a long period of abstinence, which might impact adult life.


Assuntos
Consumo Excessivo de Bebidas Alcoólicas , Etanol , Animais , Ratos , Feminino , Etanol/farmacologia , Ratos Wistar , Consumo de Bebidas Alcoólicas , Hipocampo
8.
Pharmacol Res ; 181: 106245, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35526666

RESUMO

Multidrug-resistant bacterial infections are a threat to public health worldwide, which boosts the urgent need for pharmacological research for new drugs. Although the peptides without disulfide bridges from scorpions have shown antimicrobial action, usually their toxicity hamper their pharmacological application. Stigmurin is a non-hemolytic cationic peptide from Tityus stigmurus venom with antibacterial effect and toxicity on normal cells. In this approach, the conformational changes and stability of two Stigmurin analog peptides, named StigA8 and StigA18, were evaluated by circular dichroism, as well as the mechanism of interaction with bacterial membranes in silico. In addition, the in vitro and in vivo antibacterial activity and the action against the biofilm formed by multidrug-resistant Staphylococcus aureus were investigated. StigA8 (+4) and StigA18 (+5) revealed the ability to change their structural conformation depending on the medium composition, and high stability at different temperatures and pH conditions. Both analog peptides showed greater ability to interact with bacterial membranes in silico when compared to the native one. StigA8 and StigA18 demonstrated low hemolytic action, with non-toxic effect on G. mellonella larvae up to 120 mg/kg. StigA8 and StigA18 presented a broad spectrum of antibacterial action in vitro, especially against multidrug-resistant clinical isolates. The analog peptides (7.5 µM) also reduced the biofilm biomass of multidrug-resistant S. aureus, as well as increased the larval survival of the Galleria mellonella infected larvae. Therefore, StigA8 and StigA18 showed a beneficial potential in the treatment of bacterial infections, constituting promising bioactive components for the development of new antimicrobial agents.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Venenos de Escorpião , Animais , Antibacterianos/farmacologia , Bactérias , Biofilmes , Testes de Sensibilidade Microbiana , Peptídeos/química , Peptídeos/farmacologia , Venenos de Escorpião/química , Venenos de Escorpião/farmacologia , Escorpiões/química
9.
Vet World ; 15(11): 2593-2596, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36590122

RESUMO

Background and Aim: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the global coronavirus pandemic (COVID-19) in humans in 2019. Although SARS-CoV-2 infection is primarily asymptomatic and transitory in companion animals, the role of these animals in the life cycle of the virus remains unclear. This study aimed to survey the first SARS-CoV-2 infection cases in pets, including a dog and three cats in São Paulo, Brazil. Materials and Methods: We invited COVID-19-positive pet owners to participate in the survey and obtained nasal, oropharyngeal, and rectal swab samples from their pets. These samples were placed in vials and subjected to a real-time quantitative polymerase chain reaction. In addition, the owners answered an epidemiological questionnaire, and the pets underwent clinical examination and monitoring. Results: Out of 49 sampled pets, 3/19 (15.8%) cats and 1/30 (3.3%) dogs tested positive, with wide variations in viral loads. Despite the limitations of size and non-randomized sampling, our results showed that cats are more susceptible than dogs to SARS-CoV-2 infection, presenting a cat: dog ratio of 4.8: 1. Only one cat presented mild and transitory respiratory symptoms. Conclusion: Although SARS-CoV-2 infection was detected in pets in the largest South American city and the COVID-19 epicenter at the time, these first detected pet cases displayed either none or mild clinical signs.

10.
Alcohol Clin Exp Res ; 45(1): 56-63, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33165940

RESUMO

BACKGROUND: Alcohol (EtOH) intake during adolescence has become an important public health issue. Although the detrimental effects of EtOH intake on the musculoskeletal system are well known, only a few studies have investigated its impact on the stomatognathic system of adolescents. This study aimed to investigate the effect of EtOH binge drinking on the alveolar bone and the long-term consequences after abstinence. METHODS: Adolescent female Wistar rats (35 days old) were exposed to 4 cycles of EtOH binge drinking (3 g/kg/d; 3 days On-4 days Off) or distilled water (control group). Alveolar bone micromorphology and vertical bone distance were evaluated at 1, 30, and 60 days after that last EtOH intake through X-ray computed microtomography. The mineral:matrix ratio was assessed through Raman spectroscopy. RESULTS: A decrease in both trabecular thickness and volume ratio, and an increase in trabecular separation were observed at the 1-day evaluation (immediate withdrawal). After 30 and 60 days, the alveolar bone parameters were found similar to control, except for the mineral:matrix ratio in the long-term abstinence. CONCLUSIONS: EtOH binge drinking during adolescence results in alveolar bone damage that may persist in adulthood, even after abstinence.


Assuntos
Perda do Osso Alveolar/induzido quimicamente , Etanol/efeitos adversos , Doenças Mandibulares/induzido quimicamente , Solventes/efeitos adversos , Consumo de Álcool por Menores , Perda do Osso Alveolar/diagnóstico por imagem , Animais , Feminino , Homeostase , Doenças Mandibulares/diagnóstico por imagem , Ratos Wistar , Microtomografia por Raio-X
11.
PLoS One ; 15(7): e0236386, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735581

RESUMO

This paper proposes a dynamic model to describe and forecast the dynamics of the coronavirus disease COVID-19 transmission. The model is based on an approach previously used to describe the Middle East Respiratory Syndrome (MERS) epidemic. This methodology is used to describe the COVID-19 dynamics in six countries where the pandemic is widely spread, namely China, Italy, Spain, France, Germany, and the USA. For this purpose, data from the European Centre for Disease Prevention and Control (ECDC) are adopted. It is shown how the model can be used to forecast new infection cases and new deceased and how the uncertainties associated to this prediction can be quantified. This approach has the advantage of being relatively simple, grouping in few mathematical parameters the many conditions which affect the spreading of the disease. On the other hand, it requires previous data from the disease transmission in the country, being better suited for regions where the epidemic is not at a very early stage. With the estimated parameters at hand, one can use the model to predict the evolution of the disease, which in turn enables authorities to plan their actions. Moreover, one key advantage is the straightforward interpretation of these parameters and their influence over the evolution of the disease, which enables altering some of them, so that one can evaluate the effect of public policy, such as social distancing. The results presented for the selected countries confirm the accuracy to perform predictions.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Previsões/métodos , Modelos Teóricos , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Doenças Assintomáticas , COVID-19 , China/epidemiologia , Infecções Comunitárias Adquiridas , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/virologia , Infecção Hospitalar , Confiabilidade dos Dados , Europa (Continente)/epidemiologia , Hospitalização , Humanos , Pandemias , Pneumonia Viral/mortalidade , Pneumonia Viral/virologia , SARS-CoV-2 , Estados Unidos/epidemiologia
12.
J Econ Entomol ; 112(6): 2817-2823, 2019 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-31365740

RESUMO

Bacillus thuringiensis (Berliner) has demonstrated potential use in insect pest management. We evaluated the toxicity and sublethal effects of formulations of toxic baits composed of bacterial isolates (Bt) B. thuringiensis var. oswaldo cruzi (Bto), B. thuringiensis var. israelensis (Bti), B. thuringiensis var. kurstaki (Btk), and B. circulars (Bc) in combination with three food attractants 50% grape juice, 7% sugar cane molasses, and 7% hydrolyzed protein on adults of Zaprionus indianus (Gupta, 1970), the main pest of fig fruit (Ficus carica) in Brazil. Likewise, we evaluated the toxicity on the parasitoids Trichopria anastrephae Lima, 1940 and Pachycrepoideus vindemmiae (Rondani, 1875) in ingestion bioassays. Adults of Z. indianus showed high susceptibility to Bacterial isolates. However, the Bto isolate (1013 CFU. ml-1) caused adult mortality of 100%, in 72 h after exposure, with LT50 values of ≈20 h. By using the lethal concentrations (LC90) of the Bto isolate, estimated via the concentration-response curves with the food attractants, a significant reduction (40 to 50%) in the total fecundity and in the embryonic viability of eggs from females fed with the toxic baits was observed. The food attractants + Bto (80 × 108 CFU. ml-1) did not cause significant mortality of T. anastrephae and P. vindemmiae adults (mortality < 20%). The bacterial isolates Bti, Btk, Bc, and Bto are considered promising for the formulation of toxic baits, because, besides providing toxic effect on adults of Z. indianus, they showed no toxicity on T. anastrephae and P. vindemmiae adults.


Assuntos
Bacillus thuringiensis , Drosophilidae , Himenópteros , Animais , Brasil , Feminino , Sucos de Frutas e Vegetais , Controle Biológico de Vetores
13.
SAGE Open Med Case Rep ; 7: 2050313X19834827, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30858975

RESUMO

Malignant otitis externa is an invasive infection of the external auditory canal and temporal bone with potentially life-threatening complications. Elderly patients with type 2 diabetes mellitus are the population most commonly affected by malignant otitis externa, but any type of immunosuppression predisposes to the disease. Prader-Willi syndrome is a genetic cause of obesity, often associated with insulin resistance and type 2 diabetes mellitus. This report describes a case of a 21-year-old male patient with Prader-Willi syndrome who had malignant otitis externa that progressed to sepsis during hospitalization. To the best of the authors' knowledge, this is the first description of malignant otitis externa in a young patient with Prader-Willi syndrome.

14.
J Genet ; 95(2): 349-55, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27350679

RESUMO

We conducted a cytogenetic study of four hyline frog species (Dendropsophus elegans, D. microps, D. minutus and D. werneri) from southern Brazil. All species had 2n = 30 chromosomes, with interspecific and intraspecific variation in the numbers of metacentric, submetacentric, subtelocentric and telocentric chromosomes. C-banding and fluorochrome staining revealed conservative GC-rich heterochromatin localized in the pericentromeric regions of all species. The location of the nucleolus organizer regions, as confirmed by fluorescent in situ hybridization, differed between species. Telomeric probes detected sites that were restricted to the terminal regions of all chromosomes and no interstitial or centromeric signals were observed. Our study corroborates the generic synapomorphy of 2n = 30 chromosomes for Dendropsophus and adds data that may become useful for future taxonomic revisions and a broader understanding of chromosomal evolution among hylids.


Assuntos
Anuros/genética , Centrômero/ultraestrutura , Heterocromatina/ultraestrutura , Região Organizadora do Nucléolo/ultraestrutura , Telômero/ultraestrutura , Animais , Evolução Biológica , Brasil , Bandeamento Cromossômico , Feminino , Florestas , Hibridização in Situ Fluorescente , Cariotipagem , Masculino , Ploidias , Especificidade da Espécie
15.
Artigo em Inglês | MEDLINE | ID: mdl-26737850

RESUMO

An electrocardiograph was designed and implemented, being capable of obtaining electrical signals from the heart, and sending this data via Bluetooth to a tablet, in which the signals are graphically shown. The user interface is developed as an Android application. Because of the technological progress and the increasing use of full portable systems, such as tablets and cell phones, it is important to understand the functioning and development of an application, which provides a basis for conducting studies using this technology as an interface. The project development includes concepts of electronics and its application to achieve a portable and functional final project, besides using a specific programmable integrated circuit for electrocardiogram, electroencephalogram and electromyogram, the ADS1294. Using a simulator of cardiac signals, 36 different waveforms were recorded, including normal sinus rhythm, arrhythmias and artifacts. Simulations include variations of heart rate from 30 to 190 beats per minute (BPM), with variations in peak amplitude of 1 mV to 2 mV. Tests were performed with a subject at rest and in motion, observing the signals obtained and the damage to their interpretation due to the introduction of muscle movement artifacts in motion situations.


Assuntos
Eletrocardiografia/instrumentação , Eletrocardiografia/métodos , Frequência Cardíaca/fisiologia , Microcomputadores , Processamento de Sinais Assistido por Computador/instrumentação , Arritmias Cardíacas/fisiopatologia , Humanos
16.
J Environ Radioact ; 100(10): 875-83, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19608307

RESUMO

The assembling of a system for field sampling and activity concentration measurement of radon dissolved in groundwater is described. Special attention is given in presenting the calibration procedure to obtain the radon activity concentration in groundwater from the raw counting rate registered in a portable scintillation detector and in establishing the precision of the activity concentration measurements. A field procedure was established and the system tested during one year of monthly observations of (222)Rn activity concentration in groundwater drawn from two wells drilled on metamorphic rocks exposed at Eastern São Paulo State, Brazil. The observed mean (222)Rn activity concentrations are 374Bq/dm(3) in one well and about 1275Bq/dm(3) in the other one. In both wells the (222)Rn activity concentrations showed a seasonal variation similar to variations previously reported in the literature for the same region.


Assuntos
Sedimentos Geológicos/química , Monitoramento de Radiação/instrumentação , Radônio/análise , Poluentes Radioativos da Água/análise , Água/química , Calibragem , Monitoramento de Radiação/métodos
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