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Asthma is one of the most prevalent chronic respiratory diseases, characterized by bronchial hyper-responsiveness and intermittent airflow obstruction. Short-acting ß2 agonists (SABA) remain the cornerstone of acute asthma management due to its properties in smooth muscle relaxation and bronchodilatation. Rarely, these drugs might be associated with adverse effects, including the development of metabolic and hydro-electrolytic imbalances. We report a case of lactic acidosis secondary to ß2 agonists in a young female patient admitted with severe acute asthma. After initial management and significant improvement of the respiratory distress with nebulized and subcutaneous salbutamol, the patient developed high anion gap metabolic acidosis due to hyperlactacidemia and hypokalemia. Alternative causes of lactic acidosis were discarded, such as severe hypoxemia, systemic hypoperfusion, sepsis, and organ dysfunction, and SABA-related lactic acidosis was suspected. This treatment was halted, and tachypnea, metabolic acidosis, and lactate levels rapidly resolved. The remainder of the hospital stay was uneventful, and the patient was discharged after a period of five days. Although rare, the development of unexplained lactic acidosis in a SABA-treated patient should alert the treating physician to this ß2 agonist side-effect.
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Studies on the occurrence of POPs and other persistent compounds in pristine areas are extremely valuable, as they offer insights on the long-range transportation of POPs and the occurrence of natural compound producers' areas. In this regard, this study aimed to report data of both anthropogenic (polychlorinated biphenyls, PCBs, and polybrominated diphenyl ethers, PBDEs) and natural (methoxylated PBDEs, MeO-BDEs) compounds in tissues of the black triggerfish, Melichthys niger (Tetraodontiformes, Balistidae), specimens (n = 30) sampled in 2018 during a scientific expedition conducted at Trindade Island. Concentrations of ∑28PCBs ranged from 73 to 1052 ng g-1 lw in liver, 334 to 1981 ng g-1 lw in gonads, and 20 to 257 ng g-1 lw in muscle, with the predominance of PCB-180 in liver and PCB-52 in gonad and muscle. Concentrations of ∑7PBDEs ranged from Assuntos
Monitoramento Ambiental
, Éteres Difenil Halogenados
, Poluentes Orgânicos Persistentes
, Bifenilos Policlorados
, Poluentes Químicos da Água
, Animais
, Poluentes Químicos da Água/análise
, Poluentes Químicos da Água/metabolismo
, Brasil
, Éteres Difenil Halogenados/metabolismo
, Éteres Difenil Halogenados/análise
, Bifenilos Policlorados/análise
, Bifenilos Policlorados/metabolismo
, Recifes de Corais
, Oceano Atlântico
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Background: Endolymphatic sac tumor (ELST) is a rare lesion. It may be sporadically or associated with Von Hippel-Lindau syndrome. Progressive audiovestibular symptoms characterize the typical clinical presentation. Here, we report a unique case of ELST with acute intracranial hypertension (IH) due to tumor compression, successfully treated with an urgent suboccipital decompressive craniectomy (SDC). Case Description: A 33-year-old woman previously underwent a biopsy and ventriculoperitoneal shunt. The histopathological finding revealed an ELST. One year later, she developed headache, vomiting, and somnolence due to brainstem compression. An urgent SDC was performed. One month later, preoperative endovascular embolization and partial tumor resection were carried out. After 6 months adjuvant radiotherapy (RT) therapy was administered. She has been under follow-up for 8 years since the last surgical procedure, and the tumor remains stable. Conclusion: ELST generally has a progressive clinical course. This is a unique case with acute IH due to tumor compression. The tumor's high vascularity and the unavailability of endovascular embolization precluded its resection. SDC was an alternative approach. The final treatment included tumor embolization, surgical resection, and RT. No progression was observed for 8 years after the last procedure, and long-term follow-up is warranted.
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There is growing interest in using cannabinoids across various clinical scenarios, including pain medicine, leading to the disregard of regulatory protocols in some countries. Legislation has been implemented in Brazil, specifically in the state of São Paulo, permitting the distribution of cannabinoid products by health authorities for clinical purposes, free of charge for patients, upon professional prescription. Thus, it is imperative to assess the existing evidence regarding the efficacy and safety of these products in pain management. In light of this, the São Paulo State Society of Anesthesiology (SAESP) established a task force to conduct a narrative review on the topic using the Delphi method, requiring a minimum agreement of 60% among panelists. The study concluded that cannabinoid products could potentially serve as adjuncts in pain management but stressed the importance of judicious prescription. Nevertheless, this review advises against their use for acute pain and cancer-related pain. In other clinical scenarios, established treatments should take precedence, particularly when clinical protocols are available, such as in neuropathic pain. Only patients exhibiting poor therapeutic responses to established protocols or demonstrating intolerance to recommended management may be considered as potential candidates for cannabinoids, which should be prescribed by physicians experienced in handling these substances. Special attention should be given to individual patient characteristics and the likelihood of drug interactions.
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Canabinoides , Manejo da Dor , Humanos , Canabinoides/efeitos adversos , Canabinoides/uso terapêutico , Brasil , Manejo da Dor/métodos , Anestesiologia , Sociedades Médicas , Técnica Delphi , Dor Aguda/tratamento farmacológicoRESUMO
This study explores the multifaceted influence of litter size, maternal care, exercise, and aging on rats' neurobehavioral plasticity and dentate gyrus microglia dynamics. Body weight evolution revealed a progressive increase until maturity, followed by a decline during aging, with larger litters exhibiting lower weights initially. Notably, exercised rats from smaller litters displayed higher body weights during the mature and aged stages. The dentate gyrus volumes showed no significant differences among groups, except for aged sedentary rats from smaller litters, which exhibited a reduction. Maternal care varied significantly based on litter size, with large litter dams showing lower frequencies of caregiving behaviors. Behavioral assays highlighted the detrimental impact of a sedentary lifestyle and reduced maternal care/large litters on spatial memory, mitigated by exercise in aged rats from smaller litters. The microglial dynamics in the layers of dentate gyrus revealed age-related changes modulated by litter size and exercise. Exercise interventions mitigated microgliosis associated with aging, particularly in aged rats. These findings underscore the complex interplay between early-life experiences, exercise, microglial dynamics, and neurobehavioral outcomes during aging.
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BACKGROUND: Overweight and obesity affect more than 18% of children and adolescents in the world. Obesity-related associations with brain morphology might be associated with reduced efficiency of inhibitory control. This association highlights a possible mechanism by which obesity impacts intelligence and academic achievement. Prior work indicates a mediating effect of inhibitory control on the relationship between body mass index (BMI) and intelligence and academic achievement. However, although obesity is associated with impaired math performance, we do not know whether inhibitory control also mediates the relationship between BMI and math performance. This study tests the hypothesis that inhibitory control statistically mediates the relationship between BMI and math performance. METHODS: 161 children (9 to 13 years old, 80 female) participated in the present study. We evaluated BMI; math performance, in a test composed of 20 arithmetic equations of the type x = (a × b) - c; and inhibitory control through the Flanker test. We carried out Spearman correlation tests, hierarchical multiple linear regression, and tested the confidence of the model where inhibitory control statistically mediates the indirect association between BMI and math performance. Mediation analysis in this cross-sectional study aimed to improve understanding of indirect relationships and offer insights into possible causal connections. RESULTS: Better math performance and lower BMI were associated with greater accuracy on the inhibitory control test and greater accuracy on the inhibitory control test was associated with better performance on math test. We found an indirect association between higher BMI in children and impairments in math performance, that was mediated by inhibitory control (a: -0.008, p = 0.025; b: 7.10, p = 0.0004; c: 0.05, p = 0.592; c': 0.11, p = 0.238; Indirect Effect: -0.0599, 95% CI: -0.13, -0.005). CONCLUSIONS: An indirect association between higher body mass indices in children and impairments in math performance was detected, through the impact that BMI has on inhibitory control.
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Obesidade , Sobrepeso , Criança , Adolescente , Humanos , Feminino , Índice de Massa Corporal , Estudos Transversais , MatemáticaRESUMO
BACKGROUND: Seafood consumers are widely exposed to diclofenac due to the high contamination levels often present in aquatic organisms. It is a potential risk to public health due its endocrine disruptor properties. Limited information is available about diclofenac behavior after food digestion to enable a more realistic scenario of consumer exposure. This study aimed to evaluate cooking effects on diclofenac levels, and determine diclofenac bioaccessibility by an in vitro digestion assay, using commercial fish species (seabass and white mullet) as models. The production of the main metabolite 4'-hydroxydiclofenac was also investigated. Fish hamburgers were spiked at two levels (150 and 1000 ng g-1) and submitted to three culinary treatments (roasting, steaming and grilling). RESULTS: The loss of water seems to increase the diclofenac levels after cooking, except in seabass with higher levels. The high bioaccessibility of diclofenac (59.1-98.3%) observed in both fish species indicates that consumers' intestines are more susceptible to absorption, which can be worrisome depending on the level of contamination. Contamination levels did not affect the diclofenac bioaccessibility in both species. Seabass, the fattest species, exhibited a higher bioaccessibility of diclofenac compared to white mullet. Overall, cooking decreased diclofenac bioaccessibility by up to 40% in seabass and 25% in white mullet. The main metabolite 4'-hydroxydiclofenac was not detected after cooking or digestion. CONCLUSION: Thus, consumption of cooked fish, preferentially grilled seabass and steamed or baked white mullet are more advisable. This study highlights the importance to consider bioaccessibility and cooking in hazard characterization studies. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Culinária , Diclofenaco , Digestão , Contaminação de Alimentos , Alimentos Marinhos , Diclofenaco/metabolismo , Diclofenaco/química , Animais , Contaminação de Alimentos/análise , Alimentos Marinhos/análise , Peixes/metabolismo , Bass/metabolismo , Humanos , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/química , Smegmamorpha/metabolismo , Modelos BiológicosRESUMO
BACKGROUND: There is still no consensus among surgeons on whether to perform a 1- or 2-stage surgical revision in infected shoulder arthroplasties. The aim of this systematic review and meta-analysis is to rigorously synthesize published studies evaluating the clinical outcomes, recurrence of infection, and other clinical complications in order to discuss which is the best strategy for treating periprosthetic joint infection after shoulder arthroplasty. METHODS: Upon research using the PubMed, Scopus, and Web of Science databases, in November 2022, studies that presented 1- or 2-stage surgical revision as a treatment for periprosthetic joint infection after shoulder arthroplasty and assessed the reinfection rate on these patients, as well as other clinical outcomes, with a minimum follow-up of 12 months, were included. Study quality was evaluated using the Methodological Index for Non-Randomized Studies (MINORS) score. Reinfection and complication rates were extracted, and pooled estimates were calculated using the random-effect model. RESULTS: After careful screening, 44 studies were included, 5 reporting on 1-stage and 30 on 2-stage revisions and 9 assessing both strategies. A total of 185 shoulders were reported in 1-stage revision studies, whereas 526 shoulders were reported in 2-stage revision studies. The overall pooled random-effects reinfection rate was 6.68% (95% confidence interval [CI]: 3.76-10.13), with low heterogeneity (I2 = 28%, P = .03). One-stage revision showed a reinfection rate of 1.14% (95% CI: 0.00-4.88), whereas 2-stage revision analysis revealed a reinfection rate of 8.81% (95% CI: 4.96-13.33). There were significant statistical differences between 1- and 2-stage reinfection rates (P = .04). The overall pooled rate for other clinical complications was 16.76% (95% CI: 9.49-25.15), with high heterogeneity (I2 = 70%, P < .01). One-stage revision had a complication rate of 6.11% (95% CI: 1.58-12.39), whereas the 2-stage revision complication rate was 21.26% (95% CI: 11.51-32.54). This difference was statistically significant (P = .03). CONCLUSIONS: This is the first systematic review and meta-analysis showing significant statistical differences between 1- and 2-stage surgical revision in infected shoulder arthroplasties. Provided the right conditions exist, 1-stage revision shows better results in infection control, with lower clinical complications and possible better clinical outcomes.
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Infecções Relacionadas à Prótese , Articulação do Ombro , Humanos , Ombro , Infecções Relacionadas à Prótese/cirurgia , Reinfecção , Resultado do Tratamento , Articulação do Ombro/cirurgia , Reoperação/métodos , Estudos RetrospectivosRESUMO
BACKGROUND: Increased interindividual variability in cognitive performance during aging has been proposed as an indicator of cognitive reserve. OBJECTIVE: To determine if interindividual variability performance in episodic memory (PAL), working memory (SWM), reaction time (RTI), and sustained attention (RVP) could differentiate clusters of differential cognitive performance in healthy young and older adults and search for cognitive tests that most contribute to these differential performances. METHODS: We employed hierarchical cluster and canonical discriminant function analyses of cognitive scores using the Cambridge Neuropsychological Test Automated Battery (CANTAB) to identify cognitive variability in older and young adults using the coefficient of variability of cognitive performances between and within groups. We also analyzed potential influences of age, education, and physical activity. RESULTS: Cluster analysis distinguished groups with differential cognitive performance and correlation analysis revealed coefficient of variability and cognitive performance associations. The greater the coefficient of variability the poorer was cognitive performance in RTI but not in PAL and SWM. Older adults showed diverse trajectories of cognitive decline, and better education or higher percentage of physically active individuals exhibited better cognitive performance in both older and young adults. CONCLUSION: PAL and SWM are the most sensitive tests to investigate the wide age range encompassing older and young adults. In older adults' intragroup analysis PAL showed greater discriminatory capacity, indicating its potential for clinical applications late in life. Our data underscore the importance of studying variability as a tool for early detection of subtle cognitive declines and for interpreting results that deviate from normality.
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Disfunção Cognitiva , Humanos , Idoso , Adolescente , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Envelhecimento/psicologia , Memória de Curto Prazo , Testes Neuropsicológicos , Cognição , Função ExecutivaRESUMO
Purpose: There is no consensus for management of patellar instability, even in the case of malalignment. The purpose of the review is to evaluate outcomes in the literature of MPFL reconstruction with and without tibial tubercle osteotomy. Methods: Two databases PubMed and Scopus were searched for studies comparing MPFL reconstruction with and without concomitant tibial tuberosity osteotomy. PRISMA guidelines were followed. Data on functional outcomes via Kujala score, redislocation rates and return to sport rates were reported. Results: 9 studies included data from 806 knees: 463 submitted to isolated MPFL reconstruction, and 343 submitted to the combined surgery. Patients submitted to the combined procedure had all TT-TG values superior to 18, while the ones with isolated reconstruction had more heterogeneous values, varying between 13 and 20 mm. 77.78% of the studies reported on postoperative Kujala scores, with a mean value of 83.53 in patients who underwent MPFL reconstruction alone and 83.72 in those who underwent the combined procedure. The mean difference between the two groups was -0.83, with the improvement of the score statistically significant in 22.22% of the studies, regardless of the surgery. Concerning redislocation rate, odds ratio comparing both procedures was 0.84 (p = 0.67). Conclusion: The principal finding is that the MPFL reconstruction with or without TTO resulted in similar functional outcomes, assessed by the Kujala score, and low complications concerning recurrent patellar dislocation. More robust literature is needed in the setting of a high TT-TG distance. Level of evidence: IV.
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Cognitive abilities tend to decline with aging, with variation between individuals, and many studies seek to identify genetic biomarkers that more accurately anticipate risks related to pathological aging. We investigated the influence of BDNF, NTRK2, and FNDC5 single nucleotide polymorphisms (SNPs) on the cognitive performance of young and older adults with contrasting educational backgrounds. We addressed three questions: (1) Is education associated with reduced age-related cognitive decline? (2) Does the presence of SNPs explain the variation in cognitive performance observed late in life? (3) Is education differentially associated with cognition based on the presence of BDNF, NTRK2, or FNDC5 polymorphisms? We measured the cognitive functions of young and older participants, with lower and higher education, using specific and sensitive tests of the Cambridge Automated Neuropsychological Test Assessment Battery. A three-way ANOVA revealed that SNPs were associated with differential performances in executive functions, episodic memory, sustained attention, mental and motor response speed, and visual recognition memory and that higher educational levels improved the affected cognitive functions. The results revealed that distinct SNPs affect cognition late in life differentially, suggesting their utility as potential biomarkers and emphasizing the importance of cognitive stimulation that advanced education early in life provides.
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Disfunção Cognitiva , Memória Episódica , Humanos , Idoso , Fator Neurotrófico Derivado do Encéfalo/genética , Disfunção Cognitiva/genética , Cognição/fisiologia , Polimorfismo de Nucleotídeo Único , Fibronectinas/genética , Biomarcadores , Testes NeuropsicológicosRESUMO
Introduction: Primary aldosteronism is the most common cause of secondary hypertension. Adrenal vein sampling is the gold standard for subtyping primary aldosteronism. However, this procedure is technically challenging and often has a low success rate. Our center is one of the very few performing this technique in our country with an increasing experience. Objective: The aim of this study was to evaluate the role of the cortisol intraprocedural assay in improving the performance of adrenal vein sampling. Design: We enrolled all of the patients with primary aldosteronism that underwent adrenal vein sampling from February 2016 to April 2023. The cortisol intraprocedural assay was introduced in October 2021. Methods: We enrolled a total of 50 adrenal vein samplings performed on 43 patients with the diagnosis of primary aldosteronism. In this sample, 19 patients and 24 patients underwent adrenal vein sampling before and after intraprocedural cortisol measurement, respectively. The procedure was repeated in seven patients (one before and six after intraprocedural cortisol measurement), given the unsuccess of the first exam. Selectivity of the adrenal vein sampling was assumed if the serum cortisol concentration from the adrenal vein was at least five times higher than that of the inferior vena cava. Lateralization was assumed if the aldosterone to cortisol ratio of one adrenal vein was at least four times the aldosterone to cortisol ratio of the contralateral side. Results: The mean age of the patients that underwent adrenal vein sampling (N = 43) was 55.2 ± 8.9 years, and 53.5% (n = 23) were female. The mean interval between the diagnosis of hypertension and the diagnosis of primary aldosteronism was 9.8 years (±9.9). At diagnosis, 62.8% of the patients (n = 27) had hypokalemia (mean value of 3 mmol/L (±0.34)), 88.4% (n = 38) had adrenal abnormalities on preprocedural CT scan, and 67.4% (n = 29) described as unilateral nodules. There were no statistically significant differences in the patients' baseline characteristics between the two groups (before and after intraprocedural cortisol measurement). Before intraprocedural cortisol measurement, adrenal vein sampling selectivity was achieved in 35% (n = 7) patients. Selectivity increased to 100% (30/30) after intraprocedural cortisol measurement (p < 0.001). With the exception of one patient who refused it, all patients with lateralized disease underwent unilateral adrenalectomy with normalization of the aldosterone to renin ratio postoperatively. Conclusions: The lack of effective alternatives in subtyping primary aldosteronism highlights the need to improve the success rate of adrenal vein sampling. In this study, intraprocedural cortisol measurement allowed a selectivity of 100%. Its addition to this procedure protocol should be considered, especially in centers with a low success rate.
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INTRODUCTION: Pain in children who suffer from hypoxia-ischemia (HI) events is still not widely studied. Hypoxia-ischemia is characterized by the momentary or permanent cessation of blood flow and, consequently, of oxygen supply, becoming the main cause of encephalopathy in children. Hyperalgesia was identified in animals undergoing prenatal hypoxia-ischemia by researchers from the Universidade do Estado do Rio de Janeiro (UERJ). Premature and asphyxiated newborns have been admitted to the neonatal intensive care unit (NICU) of Pedro Ernesto University Hospital (HUPE) in Brazil and are monitored by the Outpatient Follow-up of High-Risk Newborns Project (SARAR), but no pain assessment was performed. OBJECTIVE: To assess pain in children born in high-risk situations, such as prematurity and perinatal asphyxia, with higher chances of perinatal HI, discharged from the NICU/HUPE, and followed by SARAR. METHODOLOGY: The study was approved by the HUPE Research Ethics Committee. The epidemiological, descriptive, cross-sectional study started in 2021 and finished in 2023, with the application of the pain assessment tool or instrument adapted from the Lübeck Pain-Screening Questionnaire to the caregivers and with the collection of growth and development data. The population consisted of asphyxiated infants born with a gestational age greater than 35 weeks and submitted to the Therapeutic Hypothermia protocol and premature infants discharged from the NICU between two (gestational age 1 (GA1)) and 12 years old. For most of them, pain prevalence was assessed according to its frequency and intensity, as were sociodemographic variables of the child and mother, neural alterations, and the Children's Developmental Scale (DENVER II). The percentage differences between the evaluated factors and the presence of pain were performed using Fisher's exact test and medians using the non-parametric Wilcoxon rank-sum test, both appropriate for the small sample of children. Significance levels of 10% were considered for trends and 5% for statistically significant differences. RESULTS: Of the 86 children included in our search, 26 (30%) were born with a gestational age greater than 35 weeks and diagnosed with perinatal asphyxia (hereinafter referred to as the asphyxiation group), and 60 (70%) were premature. Pain was reported by 22 (25%) children, of whom 54.4% reported moderate or severe pain. The head and abdomen were the most reported sites (36%). Differences were observed in the percentage distribution of pain between asphyxiates and premature infants (11% vs. 32%; p-value 0.061 on the Fisher test) and between females and males (34% vs. 17%; p-value 0.085 on the Fisher test). Black and Brown children had higher median pain scale values than White children (p-value < 0.027, Wilcoxon rank sum test). CONCLUSION: There is a higher prevalence of pain in girls, in the head, in premature infants, and greater intensity among Black and Brown children. Therefore, knowing the pain profile can help improve their quality of life by offering treatments.
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OBJECTIVE: Due to fluoroquinolone resistances worldwide, valid alternatives for anti- biotic prophylaxis for transrectal ultrasound-guided prostate biopsy are needed, thus, we aimed to evaluate the efficacy, safety, and tolerability of prophylactic fosfomycin versus other oral prolonged antibiotic regimens, in preventing complications after transrectal ultrasound-guided prostate biopsy. METHODS: In this prospective study, patients submitted to transrectal ultrasound- guided prostate biopsy were divided into 2 groups according to the prophylactic antibiotic scheme performed: "short" (2 fosfomycin doses) versus "long" (antibiotic ≥ 8 days). One week and 1 month after transrectal ultrasound-guided prostate biopsy, we assessed complications' occurrence (lower urinary tract symptoms, fever, sepsis, hemorrhage) and adverse drug reactions. RESULTS: We included 244 patients (fosfomycin n=178, "long" antibiotic n=66). The only significant difference between groups was higher lower urinary tract symptom incidence 1 month after transrectal ultrasound-guided prostate biopsy in fosfomy- cin patients (16.85% vs. 6.06%, P=.031). However, after 1 week, lower urinary tract symptoms were tendentially frequenter on "long" antibiotic group (31.81% vs. 25.84%, P = .059). Infectious and hemorrhagic complications rate, adverse drug reactions, and recurrence to health services were similar between groups, and significantly decreased between the first week and first month. CONCLUSION: Antibiotic prophylaxis seems to impact lower urinary tract symptoms after transrectal ultrasound-guided prostate biopsy. Fosfomycin may provide slightly better outcome on the immediate period, while "long" antibiotic courses lead to significantly less lower urinary tract symptoms 1 month post-transrectal ultrasound-guided pros- tate biopsy, perhaps by preventing incipient prostatitis phenomena. Future directed studies should clarify these findings. Still, it seems feasible to ally fosfomycin advan- tages with noninferior safety, efficacy, and tolerability, allowing to reserve "long" regimens to other contexts. This is especially relevant in centers where transperineal biopsies are still not possible.
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Guiana dolphins, Sotalia guianensis, are vulnerable to extinction along their distribution on the Brazilian coast and assessing chemical pollution is of utmost importance for their conservation. For this study, 51 carcasses of Guiana dolphins were sampled across the Brazilian coast to investigate legacy and emerging brominated flame retardants (BFRs) as well as the naturally-produced MeO-BDEs. PBDEs and MeO-BDEs were detected in all samples analyzed, whereas emerging BFRs were detected in 16 % of the samples, all in Rio de Janeiro state. PBDE concentrations varied between 2.24 and 799 ng.g-1 lipid weight (lw), emerging BFRs between 0.12 and 1.51 ng.g-1 lw and MeO-BDEs between 3.82 and 10,247 ng.g-1 lw. Concentrations of legacy and emerging BFRs and natural compounds varied considerably according to the sampling site and reflected both the local anthropogenic impact of the region and the diversity/mass of biosynthesizers. The PBDE concentrations are lower than what was found for delphinids in the Northern Hemisphere around the same sampling period and most sampling sites presented mean concentrations lower than the limits for endocrine disruption known to date for marine mammals of 460 ng.g-1 lw, except for sampled from Santa Catarina state, in Southern Brazil. Conversely, MeO-BDE concentrations are higher than those of the Northern Hemisphere, particularly close to the Abrolhos Bans and Royal Charlotte formation, that are hotspots for biodiversity. Despite the elevated concentrations reported for this group, there is not much information regarding the effects of such elevated concentrations for these marine mammals. The distinct patterns observed along the Brazilian coast show that organobrominated compounds can be used to identify the ecological segregation of delphinids and that conservation actions should be planned considering the local threats.
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Golfinhos , Retardadores de Chama , Animais , Retardadores de Chama/análise , Brasil , Monitoramento Ambiental , Cetáceos , Éteres Difenil Halogenados/análiseRESUMO
Renewable energies are increasingly playing an important role in the world's energy supply. Society demands new solutions to solve environmental issues caused by fossil fuels. The importance of photovoltaic technology has been increasing and consequently, the necessity to have more accurate models to characterise the performance of solar cells during their entire lifetime has rose as well. Performance problems may appear during devices' lifetimes associated with factors, such as weather conditions or faulty installation. Cracking might occur, leading to abrupt reductions on the produced power, quite difficult and expensive to fix. The I-V curves of a defected or cracked solar cell might not have the shape imposed by the usual models as 1M5P. In this article, cracked c-Si solar cells are modelled using a novel model: d1MxP. This model is based on the discretisation of the diode's response on models as 1M5P. Instead of imposing a shape and compute some parameters to fit it on experimental data, the proposed model connects every two points. The results suggest a better fit using the proposed model in comparison with the 1M5P, not only in the original curves, but also modelling cracked cells. As consequence of a better fitting, the computation of important figures of merit as maximum power point or fill factor, reveals to be more precise. It is concluded that the proposed model might characterise the performance of a solar cell, even cracked, which is a huge advance aiming the possibility of simulating complex problems during the cells' operation lifetime.
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Nowadays, optical systems play an important role in communications. Dual depletion PIN photodiodes are common devices that can operate in different optical bands, depending on the chosen semiconductors. However, since semiconductor properties vary with the surrounding conditions, some optical devices/systems can act as sensors. In this research work, a numerical model is implemented to analyze the frequency response of this kind of structure. It considers both transit time and capacitive effects, and can be applied to compute photodiode frequency response under nonuniform illumination. The InP-In0.53Ga0.47As photodiode is usually used to convert optical into electrical power at wavelengths around 1300 nm (O-band). This model is implemented considering an input frequency variation of up to 100 GHz. The focus of this research work was essentially the determination of the device's bandwidth from the computed spectra. This was performed at three different temperatures: 275 K, 300 K, and 325 K. The aim of this research work was to analyze if a InP-In0.53Ga0.47As photodiode can act as a temperature sensor, to detect temperature variations. Furthermore, the device dimensions were optimized, to obtain a temperature sensor. The optimized device, for a 6 V applied voltage and an active area of 500 µm2, had a total length of 2.536 µm, in which 53.95% corresponded to the absorption region. In these conditions, if the temperature increases 25 K from the room temperature, one should expect a bandwidth increase of 8.374 GHz, and if it decreases 25 K from that reference, the bandwidth should reduce by 3.620 GHz. This temperature sensor could be incorporated in common InP photonic integrated circuits, which are commonly used in telecommunications.
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Chlorinated paraffins (CPs) are synthetic organic compounds of growing environmental and social concern. Short-chain chlorinated paraffins (SCCPs) were listed under the Stockholm Convention on Persistent Organic Pollutants (POPs) in 2017. Further, in 2021, medium-chain chlorinated paraffins (MCCPs) were proposed to be listed as POPs. We investigated SCCP and MCCP amounts and homolog profiles in four wild fish species from Bahía Blanca Estuary, a South Atlantic Ocean coastal habitat in Argentina. SCCPs and MCCPs were detected in 41% and 36% of the samples, respectively. SCCP amounts ranged from <12 to 29 ng g-1 wet weight and <750-5887 ng g-1 lipid weight, whereas MCCP amounts ranged from <7 to 19 ng g-1 wet weight and <440-2848 ng g-1 lipid weight. Amounts were equivalent to those found in fish from the Arctic and Antarctic Oceans and from some North American and Tibetan Plateau lakes. We performed a human health risk assessment and found no direct risks to human health for SCCP or MCCP ingestion, according to present knowledge. Regarding their environmental behavior, no significant differences were observed among SCCP amounts, sampling locations, species, sizes, lipid content, and age of the specimens. However, there were significant differences in MCCP amounts across species, which could be attributed to fish size and feeding habits. Homolog profiles in all fish were dominated by the medium-chlorinated (Cl6 and Cl7) CPs and shorter chain length CPs were the most abundant, with C10Cl6 (12.8%) and C11Cl6 (10.1%) being the predominant SCCPs and C14Cl6 (19.2%) and C14Cl7 (12.4%) the predominant MCCPs. To the best of our knowledge, this is the first study on the presence of CPs in the environment in Argentina and the South Atlantic Ocean. CP occurrence in the environment, particularly in the food chain, promotes the need for further research on their occurrence and behavior, and the impact of CPs in marine ecosystems in Argentina.