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1.
Arq Bras Cir Dig ; 37: e1814, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39230117

RESUMEN

BACKGROUND: One anastomosis gastric bypass (OAGB) has gained prominence in the search for better results in bariatric surgery. However, its efficacy and safety compared to Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) remain ill-defined. AIMS: To compare the efficacy and safety of OAGB relative to RYGB and SG in the treatment of obesity. METHODS: We systematically searched PubMed, EMBASE, Cochrane Library, Lilacs, and Google Scholar databases for randomized controlled trials comparing OAGB with RYGB or SG in the surgical approach to obesity. We pooled outcomes for body mass index, percentage of excess weight loss, type-2 diabetes mellitus remission, complications, and gastroesophageal reflux disease. Statistical analyses were performed with R software (version 4.2.3). RESULTS: Data on 854 patients were extracted from 11 randomized controlled trials, of which 422 (49.4%) were submitted to OAGB with mean follow-up ranging from six months to five years. The meta-analysis revealed a significantly higher percentage of excess weight loss at 1-year follow-up and a significantly lower body mass index at 5-year follow-up in OAGB patients. Conversely, rates of type-2 diabetes mellitus remission, complications, and gastroesophageal reflux disease were not significantly different between groups. The overall quality of evidence was considered very low. CONCLUSIONS: Our results corroborate the comparable efficacy of OAGB in relation to RYGB and SG in the treatment of obesity, maintaining no significant differences in type-2 diabetes mellitus remission, complications, and gastroesophageal reflux disease rates.


Asunto(s)
Derivación Gástrica , Humanos , Anastomosis Quirúrgica/efectos adversos , Anastomosis Quirúrgica/métodos , Derivación Gástrica/métodos , Derivación Gástrica/efectos adversos , Obesidad Mórbida/cirugía , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento
2.
Surg Neurol Int ; 15: 145, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38741988

RESUMEN

Background: Orbital hypertelorism is a rare congenital condition caused by craniofacial malformations. It consists of complete orbital lateralization, characterized by an increase in distance (above the 95th percentile) of the inner canthal (ICD), outer canthal, and interpupillary distances. It can be approached surgically, and the main techniques are box osteotomy and facial bipartition. The surgical procedure is usually performed before the age of 8. We describe here two patients who underwent late surgical correction using the box osteotomy technique. Case Description: Patient 1: A 13-year-old female presenting isolated hypertelorism with 5 cm ICD and left eye amblyopia. Patient 2: A 15-year-old female with orbital hypertelorism, 4.6 cm ICD, and nasal deformity. Both patients underwent orbital translocation surgery and had no neurological disorders. Conclusion: The article reports two cases of isolated hypertelorism treated late with the box osteotomy technique. Both surgeries were successful, with no postoperative complications. It appears that it is possible to obtain good surgical results even in patients who have not been able to undergo surgery previously.

3.
Obes Surg ; 34(5): 1917-1928, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38573390

RESUMEN

Despite the current increase in revisional bariatric surgery (RBS), data on the sustainability of weight loss remain unclear. A systematic review and meta-analysis were performed to assess weight loss outcomes in adult patients undergoing RBS with follow-up > 2 years. Twenty-eight observational studies (n = 2213 patients) were included. The %TWL was 27.2 (95%CI = 23.7 to 30.6), and there was a drop in BMI of 10.2 kg/m2 (95%CI = - 11.6 to - 8.7). The %EWL was 54.8 (95%CI = 47.2 to 62.4) but with a high risk of publication bias (Egger's test = 0.003). The overall quality of evidence was very low. Our data reinforce that current evidence on RBS is mainly based on low-quality observational studies, and further higher-quality studies are needed to support evidence-based practice.


Asunto(s)
Cirugía Bariátrica , Obesidad Mórbida , Reoperación , Pérdida de Peso , Humanos , Reoperación/estadística & datos numéricos , Obesidad Mórbida/cirugía , Resultado del Tratamiento , Femenino , Índice de Masa Corporal , Adulto , Estudios Observacionales como Asunto , Masculino
4.
BMC Public Health ; 24(1): 849, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38504228

RESUMEN

CONTEXT: Both the aging of the population and the increase in noncommunicable diseases may influence the progression and outcomes culminating in death, changing the evolution of ischemic heart diseases (IHDs) and their associated causes. Using the multiple causes of death method could help understand the magnitude of these relationships and enable better targeting of investments in health. OBJECTIVES: To evaluate the mortality from IHD in Brazil between 2006 and 2020 using the method of multiple causes and identify differences in the distribution pattern of IHD mortality by sex and geographic region. METHODS: Based on information extracted from death certificates (DCs) obtained from the database of the Department of Informatics of the Unified Health System (DATASUS), we used the multiple causes method to analyze the causes of death associated with IHD when IHD was defined as the underlying cause of death (UC) and the causes of death listed as the UC when IHD was recorded in any other lines of the DC, from 2006 to 2020, in Brazil. Subsequently, the proportion of these causes of death and differences between sexes and geographic regions were evaluated, with statistical relevance analyzed using the chi-square test, and the dependence between factors illustrated using stacked bar charts and small-world network graphs. RESULTS: When IHD was listed as the UC of death, the most frequent associated causes of death were, in descending order of frequency, acute myocardial infarction (AMI), arterial hypertension (AH), chronic ischemic heart disease (CHID), heart failure (HF), and diabetes mellitus (DM). When IHD was mentioned in any line of the DC, the most frequent UCs of death were AMI followed by DM, CIHD, chronic obstructive pulmonary disease (COPD), stroke, dyslipidemia, and, in the year 2020, COVID-19. The most frequent cause of death in women were DM as the UC and associated cause of death, AH as the UC, and CIHD and Alzheimer's disease as associated causes of death, while the most frequent causes of death in men were substance dependence as the UC and associated cause of death, and cancer as an associated cause of death. The most frequent causes of death were DM and stroke in the North and Northeast, dyslipidemia and obesity in the Midwest, Alzheimer's disease in the South and Southeast, and atherosclerotic heart disease (AHD) and COPD in the South. CONCLUSIONS: Several diseases - including AMI, AH, CIHD, HF, and DM - were the most frequent associated causes of death when IHD was recorded as the UC. In contrast, AMI, DM, CIHD, COPD, and stroke were the most frequent UCs when IHD was listed as an associated cause of death. The degree of these associations varied between sexes and geographic regions.


Asunto(s)
Enfermedad de Alzheimer , Diabetes Mellitus , Dislipidemias , Insuficiencia Cardíaca , Hipertensión , Infarto del Miocardio , Isquemia Miocárdica , Enfermedad Pulmonar Obstructiva Crónica , Accidente Cerebrovascular , Masculino , Humanos , Femenino , Causas de Muerte , Brasil/epidemiología , Diabetes Mellitus/epidemiología
5.
Bioprocess Biosyst Eng ; 47(3): 367-380, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38407617

RESUMEN

In this study, the effects of CO2 addition on the growth performance and biochemical composition of the green microalga Tetradesmus obliquus cultured in a hybrid algal production system (HAPS) were investigated. The HAPS combines the characteristics of tubular photobioreactors (towards a better carbon dioxide dissolution coefficient) with thin-layer cascade system (with a higher surface-to-volume ratio). Experimental batches were conducted with and without CO2 addition, and evaluated in terms of productivity and biomass characteristics (elemental composition, protein and lipid contents, pigments and fatty acids profiles). CO2 enrichment positively influenced productivity, and proteins, lipids, pigments and unsaturated fatty acids contents in biomass. The HAPS herein presented contributes to the optimization of microalgae cultures in open systems, since it allows, with a simple adaptation-a transit of the cultivation through a tubular portion where injection and dissolution of CO2 is efficient-to obtain in TLC systems, greater productivity and better-quality biomass.


Asunto(s)
Chlorophyceae , Microalgas , Fotobiorreactores , Biomasa , Dióxido de Carbono/metabolismo , Ácidos Grasos/metabolismo
6.
Mar Environ Res ; 191: 106167, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37725865

RESUMEN

The combined effects of climate change and ocean pollution have resulted in a noteworthy decline of canopy-forming species, impacting marine biodiversity and ecosystem functioning significantly. In this context, Sargassum cymosum, which is widely distributed along the southwestern Atlantic Ocean, serves as an excellent model among canopy-forming species to investigate these impacts on populations in different regions and environmental conditions. Here, we evaluate the ecophysiological responses of two populations of S. cymosum, from Florianopolis (warm-temperate province; WTP) and Fernando de Noronha (tropical province, TP), through of interaction of temperatures and nutrient concentrations, representing marine heatwaves and acute pollution levels. Our findings revealed a decrease in biomass in both populations, highlighting the significance of nutrient enrichment as an anthropogenic filter that might potentially inhibit the expansion of the populations from tropical regions and temperature for WTP ones. These stressors directly impacted the physiological performance of S. cymosum populations, including relative growth rates, photosynthesis, chlorophylls, carotenoids and phenolic compound levels. Although there was an increase in both parameters for the TP population, a significant loss of biomass was observed, with growth rates reaching -1.5% per day. Our results highlight the need for urgent actions to manage the eutrophication process due to its negative association with global warming, which can enhance the impacts and preclude the settlement and survival of Sargassum in warm-temperate areas considering the observed and predicted tropicalization process.


Asunto(s)
Ecosistema , Sargassum , Bosques , Biomasa , Cambio Climático , Océano Atlántico
7.
Sci Total Environ ; 892: 164818, 2023 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-37315600

RESUMEN

Global marine conservation remains fractured by an imbalance in research efforts and policy actions, limiting progression towards sustainability. Rhodolith beds represent a prime example, as they have ecological importance on a global scale, provide a wealth of ecosystem functions and services, including biodiversity provision and potential climate change mitigation, but remain disproportionately understudied, compared to other coastal ecosystems (tropical coral reefs, kelp forests, mangroves, seagrasses). Although rhodolith beds have gained some recognition, as important and sensitive habitats at national/regional levels during the last decade, there is still a notable lack of information and, consequently, specific conservation efforts. We argue that the lack of information about these habitats, and the significant ecosystem services they provide, is hindering the development of effective conservation measures and limiting wider marine conservation success. This is becoming a pressing issue, considering the multiple severe pressures and threats these habitats are exposed to (e.g., pollution, fishing activities, climate change), which may lead to an erosion of their ecological function and ecosystem services. By synthesizing the current knowledge, we provide arguments to highlight the importance and urgency of levelling-up research efforts focused on rhodolith beds, combating rhodolith bed degradation and avoiding the loss of associated biodiversity, thus ensuring the sustainability of future conservation programs.


Asunto(s)
Biodiversidad , Ecosistema , Arrecifes de Coral , Contaminación Ambiental , Bosques , Conservación de los Recursos Naturales
8.
Hematol., Transfus. Cell Ther. (Impr.) ; 44(4): 465-471, Oct.-dec. 2022. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1421531

RESUMEN

ABSTRACT Objective: Describe the clinical and laboratory characteristics and the transfusion strategy of patients at Hospital Israelita Albert Einstein with platelet refractoriness and identify their etiological characteristics. Standardize the platelet immunofluorescence technique by flow cytometry as a test for platelet compatibility in immune platelet refractoriness in transfusion support. Methods: Review of medical records of refractory platelet patients followed at HIAE from January 2011 to May 2017. Clinical-demographic data, laboratory data and identification of the use of compatible genotyped platelets for patients in need of transfusion therapy were collected. The analyzed patients were classified according to the etiology of their platelet refractoriness. To standardize the FC-PIFT technique, blood group O platelets were incubated with serum from blood group AB donors and anti-IgG monoclonal antibody to determine the negative control. In order to verify the influence of the ABO system, monoclonal anti-IgG antibodies were incubated with blood group A or B platelets and with blood group O donor serum with isohemagglutinins below and above 1/64. Results: A total of 47 patients were evaluated, a 51% (24/47) preponderance of associated immune and non-immune factors (NIPR + IPR). The most common causes of NIPR + IPR were splenomegaly (54%) and the development of HLA antibodies (88%), consistent with the literature. For patients who required therapeutic transfusion, only a small portion received compatible genotyped platelets. Conclusion: Although 60% of patients could benefit from the therapeutic transfusion of genotyped platelets, only 10% were actually transfused with this type of blood component. This reaffirms the need for investments in a bank of genotyped platelet donors.


Asunto(s)
Antígenos de Plaqueta Humana , Técnica del Anticuerpo Fluorescente Indirecta , Citometría de Flujo , Antígenos HLA , Anticuerpos
9.
Pharmaceuticals (Basel) ; 15(9)2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-36145370

RESUMEN

Flavonoids are a group of natural compounds that have been described in the literature as having anti-inflammatory, antioxidant, and neuroprotective compounds. Although they are considered versatile molecules, little has been discussed about their antiviral activities for neurotropic viruses. Hence, the present study aimed to investigate the pharmacological potential of flavonoids in the face of viruses that can affect the central nervous system (CNS). We carried out research from 2011 to 2021 using the Pubmed platform. The following were excluded: articles not in the English language, letters to editors, review articles and papers that did not include any experimental or clinical tests, and papers that showed antiviral activities against viruses that do not infect human beings. The inclusion criteria were in silico predictions and preclinical pharmacological studies, in vitro, in vivo and ex vivo, and clinical studies with flavonoids, flavonoid fractions and extracts that were active against neurotropic viruses. The search resulted in 205 articles that were sorted per virus type and discussed, considering the most cited antiviral activities. Our investigation shows the latest relevant data about flavonoids that have presented a wide range of actions against viruses that affect the CNS, mainly influenza, hepatitis C and others, such as the coronavirus, enterovirus, and arbovirus. Considering that these molecules present well-known anti-inflammatory and neuroprotective activities, using flavonoids that have demonstrated both neuroprotective and antiviral effects could be viewed as an alternative for therapy in the course of CNS infections.

12.
Hematol Transfus Cell Ther ; 44(4): 465-471, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34083156

RESUMEN

OBJECTIVE: Describe the clinical and laboratory characteristics and the transfusion strategy of patients at Hospital Israelita Albert Einstein with platelet refractoriness and identify their etiological characteristics. Standardize the platelet immunofluorescence technique by flow cytometry as a test for platelet compatibility in immune platelet refractoriness in transfusion support. METHODS: Review of medical records of refractory platelet patients followed at HIAE from January 2011 to May 2017. Clinical-demographic data, laboratory data and identification of the use of compatible genotyped platelets for patients in need of transfusion therapy were collected. The analyzed patients were classified according to the etiology of their platelet refractoriness. To standardize the FC-PIFT technique, blood group O platelets were incubated with serum from blood group AB donors and anti-IgG monoclonal antibody to determine the negative control. In order to verify the influence of the ABO system, monoclonal anti-IgG antibodies were incubated with blood group A or B platelets and with blood group O donor serum with isohemagglutinins below and above 1/64. RESULTS: A total of 47 patients were evaluated, a 51% (24/47) preponderance of associated immune and non-immune factors (NIPR + IPR). The most common causes of NIPR + IPR were splenomegaly (54%) and the development of HLA antibodies (88%), consistent with the literature. For patients who required therapeutic transfusion, only a small portion received compatible genotyped platelets. CONCLUSION: Although 60% of patients could benefit from the therapeutic transfusion of genotyped platelets, only 10% were actually transfused with this type of blood component. This reaffirms the need for investments in a bank of genotyped platelet donors.

13.
Harmful Algae ; 103: 102004, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33980444

RESUMEN

Raphidiopsis raciborskii (formerly Cylindrospermopsis raciborskii) is a freshwater cyanobacterium potentially producing saxitoxins (STX) and cylindrospermopsin. Its ecophysiological versatility enables it to form blooms in the most diverse types of environments, from tropical to temperate, and from relatively pristine to polluted. In Peri Lake, located in the subtropical south of Brazil, growing populations of STX-producing R. raciborskii have been detected since 1994, posing risks to the use of its waters that supply a population of about 100,000 inhabitants. Despite the existence of a monitoring system for the presence and toxicity of cyanobacteria in Peri Lake water, no assessment has been made in the coastal region, downstream of outflowing lake water, thereby potentially making available a toxic biomass to natural and cultivated shellfish populations in the salt water ecosystem. To address this problem, the present study evaluated environmental variables and STX concentration by profiling the outflowing waters between Peri Lake and the adjacent coastal zone. Laboratory experiments were carried out with three strains of R. raciborskii in order to confirm the effect of salinity on STX production and verify if Perna Perna mussels fed with R. raciborskii cultures would absorb and accumulate STX. Results showed that environmental concentrations of STX reach high levels (up to 6.31 µg L-1 STX eq.), especially in the warmer months, reaching the coastal zone. In laboratory tests, it was found that the strains tolerate salinities between 4 and 6 and that salinity influences the production of STX. In addition, mussels fed with R. raciborskii effectively absorb and accumulate STX, even in typically marine salinities (22 to 30), suggesting that R. raciborskii biomass remains available and toxic despite salinity shock. These results draw attention to the ecological and health risk associated with R. raciborskii blooms, both in the lake environment and in the adjacent marine environment, calling attention to the need to improve the monitoring and management systems for water and shellfish toxicity in the region of interest, as well as other places where toxic cyanobacteria of limnic origin can reach the coastal zone.


Asunto(s)
Bivalvos , Cianobacterias , Animales , Brasil , Cylindrospermopsis , Ecosistema , Saxitoxina
14.
Recent Pat Biotechnol ; 15(2): 89-101, 2021 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-33726659

RESUMEN

BACKGROUND: Medicinal plants present activities against neurodegenerative diseases with potential for the pharmaceutical industries. Therefore, the objective of this study was to investigate the current panorama of patents and articles of Brazilian medicinal plants with pharmacological activities in the Central Nervous System (CNS), regarding such aspects as the number of patents by countries, areas of knowledge, and technological maturity. METHODS: We carry out a technological exploration on the Questel Orbit® platform with the descriptors: Agave sisalana P., Amburana cearenses A., Dimorphandra mollis B., Jatropha curcas L., Poincianella pyramidalis T. and Prosopis juliflora (Sw.) DC. with pharmacological activity and scientific exploration in PubMed and Science Direct associated with the CNS in the title, abstract, and methodology. RESULTS: A total of 642 patents were identified between the years 1999-2019. India, China, and Brazil are highlighted, 6th place, out of a total of 48 countries. Of these, 30 patents were not in the National Institute of Industrial Property, and 10% are Brazilian in biotechnology and pharmaceutical products. Eleven articles were used in PubMed and Science Direct with scientific domains (anticancer, neuroprotection and anti-inflammatory). The Federal University of Bahia is highlighted, showing Technology Readiness Levels (TRL4), basic skills of pre-clinical research. CONCLUSION: Brazilian public universities have a significant role in the scientific, technological and innovative development of therapeutic assets for CNS.


Asunto(s)
Plantas Medicinales , Antiinflamatorios , Biotecnología , Sistema Nervioso Central , Patentes como Asunto
16.
J Ethnopharmacol ; 264: 113201, 2021 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-32814081

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Jatropha curcas L. (Euphorbiaceae), a medicinal plant known in Brazil as "Pinhão Manso", is highly adaptable, being cultivated in different tropical and subtropical regions of the world. Antimicrobial, antioxidant and antiinflammatory activities have been attributed to different parts of the plant. In the central nervous sytem (CNS), neuroinflammation is mediated by glial cells, mainly by astrocytes and microglia, a process that plays an important role in neurodegenerative diseases and other CNS disorders. In this study, we investigated the anti-inflammatory activity of the methanolic extract obtained from the leaves of J. curcas L. (MEJc) in primary cultures of glial cells submited to inflammatory stimulus. MATERIALS AND METHODS: Primary cultures of glial cells obtained from the cerebral cortex of neonate Wistar rats were treated with MEJc (0.1-50,000 µg mL-1) and its fractions (FnJc) (0.1 µg mL-1) with or without lipopolysaccharide of Escherichia coli (LPS) (1 µg mL-1). Cell viability was determined with MTT test. Modifications in glial cell morphology were investigated by means of phase contrast microscopy and May-Grünwald staining. The reactivity of astrocytes and microglia were investigated with immunocytochemistry for GFAP, Iba1 and transcription factor NF-kB, as well as with Greiss reaction to determine the nitric oxide (NO) production. RESULTS: MEJc at 0.1-1000 µg mL-1 was non-toxic to glial cells and the DE50 was 10.794 µg mL-1. The treatment with LPS induced the activation of astrocytes and microglia marked by morphological modifications and changes in the expression of GFAP and Iba1, as well as the increase in NF-kB expression and NO production. Treatment with MEJc inhibited the morphological modifications, changes in GFAP and Iba1 expression, and the increase in NF-kB and NO production induced by LPS. CONCLUSION: This study demonstrates that the MEJc and its fractions modulate inflammatory response of astrocytes and microglia to LPS and may be considered as a potential therapeutic strategy for neuroinflammation-related diseases.


Asunto(s)
Antiinflamatorios/farmacología , Encéfalo/citología , Encéfalo/efectos de los fármacos , Jatropha , Neuroglía/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Antiinflamatorios/aislamiento & purificación , Encéfalo/fisiología , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Células Cultivadas , Neuroglía/fisiología , Extractos Vegetales/aislamiento & purificación , Ratas , Ratas Wistar
18.
Rev Bras Med Trab ; 18(1): 2-10, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32782998

RESUMEN

BACKGROUND: Analyzing, understanding and managing fatigue risk in aviation is relevant for flight safety and to reduce human error. OBJECTIVE: To analyze probable levels of fatigue among a convenience sample of Brazilian civil aviation pilots and flight attendants and to develop appropriate methods and indicators to quantify potential fatigue risk in critical phases of flight (landings and takeoffs). METHODS: Data were obtained from flight rosters voluntarily and anonymously fed to a digital platform. Rosters were analyzed with software SAFTE-FAST, which considers homeostatic process and circadian cycles related to attention and wakefulness and sleep inertia. RESULTS: The rosters for January (n=248), May (n=259) and July (n=261) 2018 were associated with incidence of 77, 54 and 77% respectively of least one event of minimal effectiveness (<77%) during critical phases of flight. The distribution of minimal effectiveness and hazard area during critical phases of flight exhibited significant seasonal oscillation upon comparing the results for January and July relative to May 2018 (p<0.001). CONCLUSION: Relative likelihood of fatigue was high in the crew rosters, with significant seasonal oscillation of minimal effectiveness and hazard area in critical phases of flight. These results point to the need for improved roster management since prescriptive rules were insufficient to mitigate risk.


INTRODUÇÃO: Métodos de análise, compreensão e gerenciamento do risco da fadiga na aviação representam tópicos de interesse para a segurança de voo e mitigação de falhas humanas. OBJETIVO: Avaliar o provável nível de fadiga em uma amostra de conveniência de pilotos e comissários de voo da aviação regular brasileira, propondo metodologia e indicadores apropriados para a quantificação da potencial exposição ao risco da fadiga durante as fases críticas de voo (pousos e decolagens). MÉTODOS: Os dados foram obtidos por envio espontâneo e anônimo das escalas de voo para uma plataforma, sendo estas analisadas com o software Sleep, Activity, Fatigue, and Task Effectiveness / Fatigue Avoidance Scheduling Tool (SAFTE-FAST), que leva em conta o processo homeostático, os ritmos circadianos associados à atenção e vigília e a inércia do sono. RESULTADOS: As escalas dos meses de janeiro (n=248), maio (n=259) e julho (n=261) de 2018 tiveram incidência de 77, 54 e 77% de ao menos um evento com efetividade mínima nas fases críticas abaixo de 77%, respectivamente. As distribuições de efetividades mínimas e áreas de risco nas fases críticas apresentaram oscilação sazonal significativa, comparando os meses de janeiro ou julho com maio de 2018 (p<0,001). CONCLUSÕES: O estudo apontou probabilidade relativa elevada de fadiga nas escalas dos aeronautas, assim como oscilações sazonais significativas nas distribuições de efetividade mínima e aérea de risco nas fases críticas. Esses resultados indicam a necessidade de um melhor gerenciamento das escalas, visto que os limites prescritivos vigentes à época não foram suficientes para a mitigação dos riscos.

19.
Sensors (Basel) ; 20(12)2020 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-32586005

RESUMEN

This paper describes a magnetoelastic strain sensor based on the ∆E effect and discusses some materials used in its construction. A polycrystalline Fe-Al-B alloy with good quality magnetoelastic properties was used as the transducer and glued to the test object, either brass plates or rods of SAE 1010 steel. The strain-dependent magnetic field of the transducer changes the operating point of the resonator, a strip of field-annealed Metglas 2826MB3, resulting in a modification of its resonant frequency. A model was developed to simulate the strain-dependent magnetic field acting on the resonator and thus to calculate curves of resonant frequency vs. deformation. With the help of this model, differences in the shape of the frequency vs. strain curve can be understood. For a sensor with resonant frequency of 60.5 kHz glued to a rod of SAE 1010 steel, a total resonant frequency variation ∆f ~7 kHz was observed for a deformation of 1100 ppm. The geometry of this sensor is especially favorable for the remote monitoring of a steel surface, such as the wires of the tensile armor of a marine riser.

20.
Sci Total Environ ; 729: 138745, 2020 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-32498159

RESUMEN

Marine climate change mitigation initiatives have recently attracted a great deal of interest in the role of natural carbon sinks, particularly on coastal systems. Brown seaweeds of the genus Sargassum are the largest canopy-forming algae in tropical and subtropical environments, with a wide global distribution on rocky reefs and as floating stands. Because these algae present high amounts of biomass, we suggest their contribution is relevant for global carbon stocks and consequently for mitigating climate change as CO2 remover. We modelled global distributions and quantified carbon stocks as above-ground biomass (AGB) with machine learning algorithms and climate data. Sargassum AGB totaled 13.1 Pg C at the global scale, which is a significant amount of carbon, comparable to other key marine ecosystems, such as mangrove forests, salt marshes and seagrass meadows. However, specific techniques related to bloom production and management, or the utilization of biomass for biomaterials, should be fostered.


Asunto(s)
Cambio Climático , Sargassum , Biomasa , Carbono , Secuestro de Carbono , Bosques , Árboles , Clima Tropical
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