Impact of the ActTeens Program on physical activity and fitness in adolescents: a cluster randomized controlled trial.

BACKGROUND: The aim of our study was to evaluate the impact of the ActTeens Program on physical activity and health-related physical fitness among adolescents in Brazil. METHODS: The "ActTeens Program" was conducted using a cluster-randomized controlled trial during 24-week school term. The sample consisted of 317 adolescents (52.7% girls; 13.61 ± 0.70 years) from four secondary schools that were randomly assigned to intervention group (N = 169) or control group (N = 148). This school-based physical activity (PA) intervention involved two components: (i) structured physical activity sessions delivered within physical education (PE) and (ii) healthy lifestyle guidance (mHealth). The primary outcome was PA assessed using Physical Activity Questionnaire for Adolescents (PAQ-A); secondary outcomes included muscular (MF) and cardiorespiratory fitness (CRF) assessed using 90-push-up, handgrip dynamometer, standing long jump, and 20 m PACER shuttle run test. Assessments were conducted at baseline, 12- and 24-week. Intervention effects were assessed using linear mixed models (LMM). RESULTS: For the primary outcome (PA), no significant group-by-time effects were observed for physical education based-PA (0.3 score; 95%CI: -0.1; 0.6; and - 0.01 score; 95%CI: -0.03; 0.03, at 12-wk and 24-wk respectively) and total PA (-0.02 score; 95%CI: -0.2; 0.2; and - 0.01score; 95%CI: -0.2; 0.2, at 12 and 24 weeks respectively). After 24 weeks, we observed a significant group by time effects for lower body muscular fitness (12.9 cm; 95%CI, 3.2 to 22.2). CONCLUSION: The implementation of aerobic and muscle-strengthening exercises used in the ActTeens intervention did not lead to improvements in physical activity. The intervention resulted in improved lower body muscular fitness, however, we found no significant differences for upper body muscular and cardiorespiratory fitness.

Biomolecular interactions on densely coated nanoparticles: a single-molecule perspective.

DNA-modified gold nanoparticles (AuNPs) play a pivotal role in bio-nanotechnology, driving advancements in bio-sensing, bio-imaging, and drug delivery. Synthetic protocols have focused on maximizing the receptor density on particles by fine-tuning chemical conditions, particularly for DNA. Despite their significance, the understanding of hybridization kinetics on functionalized AuNPs is lacking, particularly how this kinetics depends on DNA density and to what extent it varies from particle-to-particle. This study explores the molecular mechanisms of DNA hybridization on densely coated AuNPs by employing a combination of single-molecule microscopy and coarse-grained molecular dynamics simulations providing a quantification of the molecular rate constants for single particles. Our findings demonstrate that DNA receptor density and the presence of spacer strands profoundly impact association kinetics, with short spacers enhancing association rates by up to ∼15-fold. In contrast, dissociation kinetics are largely unaffected by receptor density within the studied range. Single-particle analysis directly reveals variability in hybridization kinetics, which is analyzed in terms of intra- and inter-particle heterogeneity. A coarse-grained DNA model that quantifies hybridization kinetics on densely coated surfaces further corroborates our experimental results, additionally shedding light on how transient base pairing within the DNA coating influences kinetics. This integrated approach underscores the value of single-molecule studies and simulations for understanding DNA dynamics on densely coated nanoparticle surfaces, offering guidance for designing DNA-functionalized nanoparticles in sensor applications.

Biological effects of trans, trans-farnesol in Leishmania amazonensis.

Introduction: Farnesol, derived from farnesyl pyrophosphate in the sterols biosynthetic pathway, is a molecule with three unsaturations and four possible isomers. Candida albicans predominantly secretes the trans, trans-farnesol (t, t-FOH) isomer, known for its role in regulating the virulence of various fungi species and modulating morphological transition processes. Notably, the evolutionary divergence in sterol biosynthesis between fungi, including Candida albicans, and trypanosomatids resulted in the synthesis of sterols with the ergostane skeleton, distinct from cholesterol. This study aims to assess the impact of exogenously added trans, trans-farnesol on the proliferative ability of Leishmania amazonensis and to identify its presence in the lipid secretome of the parasite. Methods: The study involved the addition of exogenous trans, trans-farnesol to evaluate its interference with the proliferation of L. amazonensis promastigotes. Proliferation, cell cycle, DNA fragmentation, and mitochondrial functionality were assessed as indicators of the effects of trans, trans-farnesol. Additionally, lipid secretome analysis was conducted, focusing on the detection of trans, trans-farnesol and related products derived from the precursor, farnesyl pyrophosphate. In silico analysis was employed to identify the sequence for the farnesene synthase gene responsible for producing these isoprenoids in the Leishmania genome. Results: Exogenously added trans, trans-farnesol was found to interfere with the proliferation of L. amazonensis promastigotes, inhibiting the cell cycle without causing DNA fragmentation or loss of mitochondrial functionality. Despite the absence of trans, trans-farnesol in the culture supernatant, other products derived from farnesyl pyrophosphate, specifically α-farnesene and ß-farnesene, were detected starting on the fourth day of culture, continuing to increase until the tenth day. Furthermore, the identification of the farnesene synthase gene in the Leishmania genome through in silico analysis provided insights into the enzymatic basis of isoprenoid production. Discussion: The findings collectively offer the first insights into the mechanism of action of farnesol on L. amazonensis. While trans, trans-farnesol was not detected in the lipid secretome, the presence of α-farnesene and ß-farnesene suggests alternative pathways or modifications in the isoprenoid metabolism of the parasite. The inhibitory effects on proliferation and cell cycle without inducing DNA fragmentation or mitochondrial dysfunction raise questions about the specific targets and pathways affected by exogenous trans, trans-farnesol. The identification of the farnesene synthase gene provides a molecular basis for understanding the synthesis of related isoprenoids in Leishmania. Further exploration of these mechanisms may contribute to the development of novel therapeutic strategies against Leishmania infections.

Social isolation leads to mild social recognition impairment and losses in brain cellularity.

Chronic social stress is a significant risk factor for several neuropsychiatric disorders, mainly major depressive disorder (MDD). In this way, patients with clinical depression may display many symptoms, including disrupted social behavior and anxiety. However, like many other psychiatric diseases, MDD has a very complex etiology and pathophysiology. Because social isolation is one of the multiple depression-inducing factors in humans, this study aims to understand better the link between social stress and MDD using an animal model based on social isolation after weaning, which is known to produce social stress in mice. We focused on cellular composition and white matter integrity to establish possible links with the abnormal social behavior that rodents isolated after weaning displayed in the three-chamber social approach and recognition tests. We used the isotropic fractionator method to assess brain cellularity, which allows us to robustly estimate the number of oligodendrocytes and neurons in dissected brain regions. In addition, diffusion tensor imaging (DTI) was employed to analyze white matter microstructure. Results have shown that post-weaning social isolation impairs social recognition and reduces the number of neurons and oligodendrocytes in important brain regions involved in social behavior, such as the anterior neocortex and the olfactory bulb. Despite the limitations of animal models of psychological traits, evidence suggests that behavioral impairments observed in patients might have similar biological underpinnings.

Brakemyia, a New Neotropical Jackal Fly Genus of Milichiidae (Insecta: Diptera) Associated with Carton Ant Nest.

Brakemyia metallica gen. et sp. nov. (Diptera, Milichiidae) is described and illustrated based on male and female specimens reared from carton nests of the ant Azteca aff. chartifex Forel (Formicidae: Dolichoderinae). The new genus is widely distributed in the Brazilian Amazon, and it can be readily distinguished from the other Neotropical genera by the broadened lunule, which extends well posterior of the antennae, and the hypandrial complex parallel to epandrium.

Correction: Concentration and temperature dependent interactions and state diagram of dispersions of copolymer microgels.

Correction for 'Concentration and temperature dependent interactions and state diagram of dispersions of copolymer microgels' by José Ruiz-Franco et al., Soft Matter, 2023, 19, 3614-3628, https://doi.org/10.1039/D3SM00120B.

Use of Botulinum Toxin as a Treatment of Hemiplegic Shoulder Pain Syndrome: A Randomized Trial.

OBJECTIVE: The primary objective of this paper is to assess whether the use of 200 units of abobotulinum in the pectoralis major and subscapularis muscles modifies the pain complaint assessed using the visual analog scale in subjects with shoulder pain after the onset of spastic hemiplegia due to cerebrovascular disease when compared to the application of a placebo to the same muscles. DESIGN: A prospective, double-blind, randomized, and placebo-controlled clinical trial study in two different rehabilitation centers. SETTING: Two distinct outpatient neurological rehabilitation services. PARTICIPANTS: Patients older than 18 years who were included presented upper limb spasticity resulting from ischemic or hemorrhagic stroke and a diagnosis of Painful Hemiplegic Shoulder Syndrome (PHSS) that was independent of motor dominance. INTERVENTIONS: Patients were divided into two groups, one of them underwent the application of botulinum toxin (TXB-A) in the pectoralis major and subscapularis muscles, at a total dose of 400 U. MAIN OUTCOME MEASURE: Patients were assessed for a change in pain using the Visual Analog Scale (VAS) for at least 13 mm. RESULTS: An improvement in pain and spasticity levels in both groups, more intense in the toxin group, but without statistical significance. The comparison between the groups showed a reduction in pain by VAS (p = 0.52). CONCLUSIONS: The use of botulinum toxin in the subscapularis and pectoralis major muscles resulted in a reduction in shoulder pain in spastic hemiplegic patients without statistical significance.

Concentration and temperature dependent interactions and state diagram of dispersions of copolymer microgels.

We investigate by means of small angle neutron scattering experiments and numerical simulations the interactions and inter-particle arrangements of concentrated dispersions of copolymer poly(N-isopropylacrylamide)-poly(ethylene glycol methyl ether methacrylate) (PNIPAM-PEGMA) microgels across the volume phase transition (VPT). The scattering data of moderately concentrated dispersions are accurately modeled at all temperatures by using a star polymer form factor and static structure factors calculated from the effective potential obtained from simulations. Interestingly, for temperatures below the VPT temperature (VPTT), the radius of gyration and blob size of the particles significantly decrease with increasing the effective packing fraction in the non-overlapping regime. This is attributed to the presence of charges in the system associated with the use of an ionic initiator in the synthesis. Simulations using the experimentally corroborated interaction potential are used to explore the state diagram in a wide range of effective packing fractions. Below and slightly above the VPTT, the system undergoes an arrest transition mainly driven by the soft repulsion between the particles. Only well above the VPTT the system is found to phase separate before arresting. Our results highlight the versatility and potential of copolymer PNIPAM-PEGMA microgels to explore different kinds of arrested states balancing attraction and repulsion by changing temperature and packing fraction.

Implementation of different strategies of the "ActTeens" intervention for adolescents: a process evaluation / Implementação das diferentes estratégias da intervenção "ActTeens" para adolescentes: uma avaliação do processo

Multicomponent programs to promote physical activity have shown promise to help adolescents to increase physical activity levels. Although evaluation of the intervention implementation process is important, information about this evaluation is rarely reported. This observational study aimed to evaluate the implementation of a 12-week physical activity intervention program for adolescents. The ActTeens program consists of three components: (1) structured physical activity sessions; (2) self-monitoring associated with daily goal setting; (3) healthy lifestyle messages (mHealth). The evaluation of the process was carried out through observations and self-reported information from the students. Fifty-one adolescents (37.5% girls) answered the questionnaire. Overall, the reach was 73.3%, retention rate 96.3%, and satisfaction with the intervention was high (score 5). The structured sessions presented high fidelity, and good acceptability among adolescents, with an average attend-ance rate of 93.7%. Participants rated the sessions as enjoyable and the teacher's role as excellent. Adherence to self-monitoring (goal setting with a pedometer) was moderate and 57.8% of adoles-cents reported using the device daily. In addition, adolescents reported that the use of a pedometer increased their motivation to practice physical activity (72.4%). Satisfaction with the messages was considered low, with only 37.8% agreeing that the messages promoted the adoption of a healthy lifestyle. In conclusion, the structured sessions and the self-monitoring showed good acceptability among adolescents, and these strategies were considered relevant to promote a more physically active lifestyle. However, the component mHealth, when used as a single strategy, did not aid the adoption of healthy behavior

Programas multicomponentes para promoção da atividade física têm se mostrado promissores para auxiliar os adolescentes a aumentar seus níveis de atividade física. Embora a avaliação do processo de implementação da intervenção seja importante, informações sobre esta avaliação raramente são relatadas. O presente estudo teve como objetivo avaliar a implementação de um programa de intervenção de atividade física de 12 sema-nas para adolescentes. O programa ActTeens consiste de três componentes principais: (1) sessões estruturadas de atividade física; (2) auto-monitoramento associado com estabelecimento de metas diárias; (3) orientações sobre um estilo de vida saudável (mHealth). A avalição do processo foi por meio de observações e informações autorreferidas dos alunos. Cinquenta e um adolescentes (37,5% meninas) responderam o questionário. No geral, o alcance foi de 73,3%, a taxa de retenção 96,3% e satisfação com a intervenção foi alta (escore 5). As sessões estruturadas tiveram alta fidelidade, boa aceitabilidade entre os adolescentes com a frequência média de participação de 93,7% por aula. Os participantes classificaram as sessões como prazerosas e o papel do pro-fessor como excelente. A aderência ao automonitoramento (estabelecimento de metas com pedômetro) foi mode-rada e 57,8% dos adolescentes relataram usar o dispositivo diariamente. Além disso, os adolescentes relataram que o uso do pedômetro aumentou a motivação para a prática de atividade física (72,4%). A satisfação com as mensagens por aplicativo foi considerada baixa, sendo que apenas 37,8% concordaram que as mensagens promoveram a adoção de um estilo de vida saudável. Em conclusão, as sessões estruturadas e o uso do pedô-metro para automonitoramento mostraram boa aceitabilidade entre os adolescentes, e estas estratégias foram consideradas relevantes para promover um estilo de vida fisicamente mais ativo. Entretanto, o componente mHealth, quando usado como uma estratégia única, não auxiliou na adoção de um comportamento saudável

Probing Temperature Responsivity of Microgels and Its Interplay with a Solid Surface by Super-Resolution Microscopy and Numerical Simulations.

Super-resolution microscopy has become a powerful tool to investigate the internal structure of complex colloidal and polymeric systems, such as microgels, at the nanometer scale. An interesting feature of this method is the possibility of monitoring microgel response to temperature changes in situ. However, when performing advanced microscopy experiments, interactions between the particle and the environment can be important. Often microgels are deposited on a substrate, since they have to remain still for several minutes during the experiment. This study uses direct stochastic optical reconstruction microscopy (dSTORM) and advanced coarse-grained molecular dynamics simulations to investigate how individual microgels anchored on hydrophilic and hydrophobic surfaces undergo their volume phase transition with temperature. We find that, in the presence of a hydrophilic substrate, the structure of the microgel is unperturbed and the resulting density profiles quantitatively agree with simulations performed under bulk conditions. Instead, when a hydrophobic surface is used, the microgel spreads at the interface and an interesting competition between the two hydrophobic strengths,monomer-monomer vs monomer-surface,comes into play at high temperatures. The robust agreement between experiments and simulations makes the present study a fundamental step to establish this high-resolution monitoring technique as a platform for investigating more complex systems, these being either macromolecules with peculiar internal structure or nanocomplexes where molecules of interest can be encapsulated in the microgel network and controllably released with temperature.

Treatment of pregnant and early postpartum women with severe and critical COVID-19: experience at a tertiary center.

BACKGROUND: The management of acute respiratory failure during pregnancy is a poorly defined issue in the literature, especially regarding the use of the prone position and the appropriate time for delivery. This study describes our experience in treating pregnant and postpartum women with severe or critical coronavirus disease 2019 (COVID-19). MATERIALS AND METHODS: This descriptive retrospective study included 25 pregnant and 4 postpartum women admitted to an ICU due to respiratory complications from COVID-19 from June 2020 to August 2021. RESULTS: The mean maternal age was 33.6 years, and the median gestational age (GA) at admission was 33 weeks. Obesity was the most common comorbidity. The median time between symptom onset and ICU admission was 10 days, while the median length of ICU stay was 14 days. Invasive mechanical ventilation (IMV) was required in 16 (55.2%) patients for a median time of 16.5 days. Prone positioning (PP) was performed in 68.7% of the patients on IMV, and resulted in an expressive increase in arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2 ratio). Eleven (44%) pregnant women delivered during their ICU stay for obstetric or fetal reasons: of these, 2 (18%) developed postpartum hemorrhagic shock and 1 (9%) developed abdominal wall infection. None of the 25 pregnant women underwent delivery due to acute respiratory failure or in an attempt to avoid intubation. There were 2 fetal deaths, but no maternal or neonatal deaths. CONCLUSION: We observed favorable outcomes in pregnant and postpartum women with severe and critical COVID-19 admitted to our institution. This finding reinforces the effectiveness of PP in the treatment of hypoxemic respiratory failure secondary to COVID-19 in pregnant women undergoing IMV, and suggests that gestation should only be interrupted in cases of obstetric and fetal complications, provided the patient is stable, or when hypoxemia is refractory to PP.

Flesh Flies (Diptera: Sarcophagidae) From the Brazilian Amazonian Savannas, a Poorly Sampled and Threatened Environment.

The Amazonian region is composed by many kinds of environments, including the Amazonian savannas, which comprise about 5% of the Amazon biome in Brazil. The biota of Amazonian savannas is poorly known, especially for insects. In this study, we performed a faunistic inventory of flesh flies (Diptera: Sarcophagidae) of four Brazilian Amazon savannas, where we recorded two subfamilies, 16 genera, and 40 species, two of which are described as new to science: Lepidodexia (Notochaeta) helenae sp. nov. and Lipoptilocnema augustoi sp. nov. Oxysarcodexia graminifoliaSouza, Pape & Thyssen, 2020 is recorded for the first time for Brazil. Dexosarcophaga paulistanaLopes (1982), Helicobia biplagiataDodge, 1966, Helicobia cearensisTibana, 1976, Oxysarcodexia simplicoides (Lopes, 1933), and Oxyvinia excisa (Lopes, 1950) are newly recorded for the Brazilian Amazon. Oxysarcodexia nitidaSoares & Mello-Patiu, 2010 is a new record for the state of Pará. The species D. paulistana is redescribed, and photographs and detailed illustrations of male terminalia are provided.

A new species of Neoscutops Malloch (Diptera: Periscelididae) reared from an ant nest.

A new species of Neoscutops Malloch (Diptera: Periscelididae), Neosctups rungae sp. nov., is described from the Brazilian Amazon based on three specimens (2 males and 1 female) reared from carton nests of the ant Azteca aff. chartifex Forel (Formicidae: Dolichoderinae). The new species belongs to the rotundipennis species-group, which is now composed of five valid species. The new species can be readily diagnosed by the following combination of characters: face fully dark brown and surstylus with a basal rounded projection on inner margin.

Improving physical activity behaviors, physical fitness, cardiometabolic and mental health in adolescents - ActTeens Program: A protocol for a randomized controlled trial.

This trial aims to investigate the effects of the ActTeens physical activity program, on adolescents' physical activity level, health-related fitness, cardiometabolic and mental health. The trial will aim to recruit ~140 adolescents (aged 13-14 years). Participants will be randomized into either intervention or control groups. The intervention will be guided by social cognitive theory and self-determination theory and implemented over one school term (24-weeks). The ActTeens Program will include: (1) structured physical activity sessions delivered within physical education, including movement-based games and dynamic stretching warm-ups; resistance training skill development; high-intensity training workouts; and cool-downs; (2) self-monitoring plus goal setting for physical activity by pedometer-smart wearable; and (3) healthy lifestyle guidance (social support) by WhatsApp® messages about healthy eating and regular physical activity for the intervention and parents groups. Study outcomes will be assessed at baseline, 24-weeks from baseline, and 12-months from baseline. Physical activity (accelerometer) is the primary outcome. Secondary outcomes include muscular and cardiorespiratory fitness, cardiometabolic profile, and mental health. A process evaluation will be conducted (i.e., recruitment, retention, attendance, and program satisfaction). This project will have the potential to address many questions and debates regarding the implementation of physical activity interventions in low-and- middle-income countries. Trial registration: ClinicalTrials.gov NCT05070377. Registered on 7 October 2021.

Assessment of the Oral Health Impact Profile (OHIP-14) improvement of different treatments for dentin hypersensitivity in noncarious cervical lesions-a randomized clinical study.

OBJECTIVES: To assess the improvement on oral health-related quality of life (OHRQoL) of individuals with cervical dentin hypersensitivity (CDH) with the noncarious cervical lesion (NCCLs) subjected to different treatments. MATERIAL AND METHODS: A single-blind randomized clinical trial was conducted with patients (n = 74) randomly allocated into three groups according to the treatment performed: PO, potassium oxalate (Oxa-Gel BF); LL, low-power laser irradiation; and POLL, potassium oxalate (Oxa-Gel BF) associated with low-power laser irradiation. The treatments were applied in four steps, weekly. The questionnaire Oral Health Impact Profile (OHIP-14) was applied before initiating and immediately after the fourth session. The greater the sum of the score, the smaller the measurement of OHRQoL. RESULTS: The total mean values of the variables at the final moment were significantly lower than the initial one for all dimensions (p value ranging from < 0.001 to 0.006). Furthermore, the OHIP-14 scores final analysis between the groups indicated that the POLL group compared to LL had a significantly lower final score for the functional limitation (p = 0.009), physical pain (p = 0.049), and psychological discomfort (p = 0.035) dimensions and that group PO compared to group LL had a significantly lower final score for the functional limitation dimension (p = 0.024). CONCLUSIONS: There was a reduction in the OHIP-14 score for all dimensions, indicating an improvement in patients' quality of life after the use of desensitizing therapies. Patients in group LL had a higher functional limitation, physical pain, and psychological discomfort. CLINICAL RELEVANCE: This study indicated improvement of desensitizing therapies for CDH to improve patients' OHRQoL. TRIAL REGISTRATION: This trial was registered in the Brazilian Clinical Trials Registry Platform (REBEC protocol number RBR-4ybjmt).

Link between Morphology, Structure, and Interactions of Composite Microgels.

We combine small-angle scattering experiments and simulations to investigate the internal structure and interactions of composite poly(N-isopropylacrylamide)-poly(ethylene glycol) (PNIPAM-PEG) microgels. At low temperatures the experimentally determined form factors and the simulated density profiles indicate a loose internal particle structure with an extended corona that can be modeled as a starlike object. With increasing temperature across the volumetric phase transition, the form factor develops an inflection that, using simulations, is interpreted as arising from a conformation in which PEG chains are incorporated in the interior of the PNIPAM network. This gives rise to a peculiar density profile characterized by two dense, separated regions, at odds with configurations in which the PEG chains reside on the surface of the PNIPAM core. The conformation of the PEG chains also have profound effects on the interparticle interactions: Although chains on the surface reduce the solvophobic attraction typically experienced by PNIPAM particles at high temperatures, PEG chains inside the PNIPAM network shift the onset of attractive interaction at even lower temperatures. Our results show that by tuning the morphology of the composite microgels, we can qualitatively change both their structure and their mutual interactions, opening the way to explore new collective behaviors of these objects.

Biological and economic responses to increasing nitrogen rates in Mombaça guinea grass pastures.

Nitrogen fertilization has been recognized as an essential tool towards the establishment of sustainable intensification of pasture-based livestock systems using tropical perennial grasses if, for a given ecosystem it is capable of increasing forage growth, stocking rates and animal performance. This study assessed pasture growth traits, nutritive value, animal and economic responses of Panicum maximum cv. Mombaça guinea grass pastures subjected to different levels of N fertilization (100 (N100), 200 (N200), and 300 (N300) kg N ha-1 yr-1). Pastures were managed under rotational stocking to maintain similar pre (80-90 cm) and post-grazing (45 cm) canopy heights. A partial budget and a Benefit-Cost Analysis were used to assess the economic returns on increasing N fertilization. N300 resulted in greater post-grazing herbage mass. A slightly higher neutral fiber and acid lignin detergent was observed at N100 (P < 0.05); crude protein increased linearly, and in vitro digestible organic matter reached maximum value at 265.4 kg N ha-1 yr-1. Annual averages of animal weight gain were 515, 590 and 660 g d-1, respectively, for N100, N200 and N300. There was a decrease from 3.7 to 1.9 kg of body weight gain per kg of additional N applied when increasing N rates from 100 to 200 and from 100 to 300 kg ha-1. The net profit improved with increasing N levels, but at reducing rates, reaching its maximum at the N300 level. The change from 100 to 200 kg N ha-1 presented the best return, with USD 3.73 for each additional dollar invested, while the change from 200 kg N ha-1 to 300 kg N ha-1 was economically less than optimal, recouping only USD 1.60 for each dollar. The N300 rate presented the highest net profit per hectare (accounting profit), even in a pessimist scenario (25% reduction in production). Despite being profitable, the N300 rate was less than optimal from an economic standpoint, since an additional 100 kg of Nitrogen ha-1 to change from N200 to N300 level reduced both the net returns and the Benefit-Cost ratio. Our results suggest that the economically optimal level of N fertilization for Mombaça guinea grass pasture should be between 200 and 300 kg ha-1.

Remoção Percutânea de Eletrodos de Estimulação Cardíaca Artificial em um Único Centro Sul-Americano / Percutaneous Removal of Cardiac Leads in a Single Center in South America

Resumo Fundamento: Nas últimas décadas, o número de dispositivos eletrônicos cardíacos implantáveis (DCEI) aumentou consideravelmente, assim como a necessidade de remoção destes. Neste contexto, a remoção percutânea apresenta-se como uma técnica segura e capaz de evitar uma cirurgia cardíaca convencional. Objetivos: Primário: descrever a taxa de sucesso e complicações da remoção percutânea de DCEI em um hospital público brasileiro. Secundário: estabelecer preditores de sucesso e complicações. Métodos: Serie de casos retrospectiva de todos os pacientes submetidos à remoção de DCEI em um hospital público brasileiro no período de janeiro de 2013 a junho de 2018. Remoção, explante e extração de eletrodos, complicações e desfechos foram definidos conforme a diretriz norte-americana de 2017. Variáveis categóricas foram comparadas pelos testes Qui-quadrado ou Fisher, enquanto variáveis contínuas, por testes não pareados. O nível de significância adotado nas análises estatísticas foi de 5%. Resultados: 61 pacientes foram submetidos à remoção de DCEI, sendo 51 extrações e 10 explantes. No total, 128 eletrodos foram removidos. Taxa de sucesso clínico foi 100% no grupo do explante e 90,2% no da extração (p=0,58). Complicações maiores foram encontradas em 6,6% dos pacientes. Falha do procedimento foi associada a eletrodos de ventrículo (p=0,05) e átrio (p=0,04) direito implantados há mais tempo. Duração do procedimento (p=0,003) e necessidade de transfusão sanguínea (p<0,001) foram associadas a maior índice de complicação. Conclusão: As taxas de complicação e sucesso clínico observadas foram de 11,5% e 91,8%, respectivamente. Remoções de eletrodos atriais e ventriculares mais antigos estiveram associados a menores taxa de sucesso. Procedimentos mais longos e necessidade de transfusão sanguínea foram associados a complicações.

Abstract Background: In the last decade, the number of cardiac electronic devices has risen considerably and consequently the occasional need for their removal. Concurrently, the transvenous lead removal became a safe procedure that could prevent open-heart surgery. Objective: The primary objective of this study was to describe the successful performance and the complication rates of pacemaker removals in a Brazilian public hospital. Our secondary aim was to describe the variables associated to successes and complications. Methods: A retrospective case series was conducted in patients submitted to pacemaker removal in a Brazilian public hospital from January 2013 to June 2018. Removal, explant, extraction, success and complication rates were defined by the 2017 Heart Rhythm Society Guideline. Categorical variables were compared using x2 or Fisher's tests, while continuous variables were compared by unpaired tests. A p-value of 0.05 was considered statistically significant. Results: Cardiac device removals were performed in 61 patients, of which 51 were submitted to lead extractions and 10 to lead explants. In total, 128 leads were removed. Our clinical success rate was 100% in the explant group and 90.2% in the extraction one (p=0.58). Major complications were observed in 6.6% patients. Procedure failure was associated to older right ventricle (p=0.05) and atrial leads (p=0,04). Procedure duration (p=0.003) and need for blood transfusion (p<0,001) were associated to more complications. Conclusion: Complications and clinical success were observed in 11.5% and 91.8% of the population, respectively. Removal of older atrial and ventricular leads were associated with lower success rates. Longer procedures and blood transfusions were associated with complications.

Sterol profile of Neobenedenia melleni, a marine ectoparasite fish.

Neobenedenia melleni, a marine fish ectoparasite, is responsible for considerable losses in the mariculture industry. In maintaining the parasite's homeostasis, sterols are structural and functional lipids that perform vital functions. Thus, understanding the mechanisms of biosynthesis and the uptake of sterols can reveal potential pharmacological targets. The objective of this work was thereby to characterize the N. melleni sterols. The most abundant sterol found was cholesterol in either its free (47.48 ± 15.93 %) or esterified form. However, its precursors, squalene (3.53 ± 0.92 %) and desmosterol (0.25 ± 0.03 %), were also found, suggesting the uptake of these intermediates from hosts or an unusual active pathway of sterol biosynthesis, which can be further explored as pharmacological targets.

Myelination of Callosal Axons Is Hampered by Early and Late Forelimb Amputation in Rats.

Deafferentation is an important determinant of plastic changes in the CNS, which consists of a loss of inputs from the body periphery or from the CNS itself. Although cortical reorganization has been well documented, white matter plasticity was less explored. Our goal was to investigate microstructural interhemispheric connectivity changes in early and late amputated rats. For that purpose, we employed diffusion-weighted magnetic resonance imaging, as well as Western blotting, immunohistochemistry, and electron microscopy of sections of the white matter tracts to analyze the microstructural changes in the corticospinal tract and in the corpus callosum (CC) sector that contains somatosensory fibers integrating cortical areas representing the forelimbs and compare differences in rats undergoing forelimb amputation as neonates, with those amputated as adults. Results showed that early amputation induced decreased fractional anisotropy values and reduction of total myelin amount in the cerebral peduncle contralateral to the amputation. Both early and late forelimb amputations induced decreased myelination of callosal fibers. While early amputation affected myelination of thinner axons, late amputation disrupted axons of all calibers. Since the CC provides a modulation of inhibition and excitation between the hemispheres, we suggest that the demyelination observed among callosal fibers may misbalance this modulation.