A LC-MS/MS method for the simultaneous determination of 6-cyanodopamine, 6-nitrodopamine, 6-nitrodopa, 6-nitroadrenaline and 6-bromodopamine in human plasma and its clinical application in patients with chronic kidney disease.

The aim of this study was to develop a high-performance liquid chromatography-tandem mass spectrometry method for the determination of 6-cyanodopamine, 6-nitrodopamine, 6-nitrodopa, 6-nitroadrenaline and 6-bromodopamine in human plasma samples. Strata-X 33 µm solid-phase extraction cartridges were used for the extraction of the catecholamines from human plasma samples. The catecholamines were separated in a 150 × 3 mm Shim-pack GIST C18-AQ column with 3 µm particle size, placed in an oven at 40°C and perfused with 82% mobile phase A (acetonitrile-H2O; 90:10, v/v) + 0.4% acetic acid and 18% mobile phase B (deionized H2O) + 0.2% formic acid at a flow rate of 340 µl/min in isocratic mode. The injected volume was 4 µl and the run lasted 4 min. The method was linear from 0.1 to 20 ng/ml and the lower limit of quantification was 0.1 ng/ml for all analytes. The method was applied to evaluate the plasma levels of catecholamines in plasma of patients with chronic kidney disease and allowed the detection for the first time of circulating levels of the novel catecholamines 6-bromodopamine and 6-cyanodopamine.

Adenanthin Is an Efficient Inhibitor of Peroxiredoxins from Pathogens, Inhibits Bacterial Growth, and Potentiates Antibiotic Activities.

The emergence and re-emergence of bacterial strains resistant to multiple drugs represent a global health threat, and the search for novel biological targets is a worldwide concern. AhpC are enzymes involved in bacterial redox homeostasis by metabolizing diverse kinds of hydroperoxides. In pathogenic bacteria, AhpC are related to several functions, as some isoforms are characterized as virulence factors. However, no inhibitor has been systematically evaluated to date. Here we show that the natural ent-kaurane Adenanthin (Adn) efficiently inhibits AhpC and molecular interactions were explored by computer assisted simulations. Additionally, Adn interferes with growth and potentializes the effect of antibiotics (kanamycin and PMBN), positioning Adn as a promising compound to treat infections caused by multiresistant bacterial strains.

Recent stationary phase-based fractionation strategies in proteomic analysis.

In this article, we review stationary phase-assisted sample prefractionation in proteomic analysis in 2019-2022 period. Applications are grouped according to the mode of retention used in the prefractionation step prior to the final analysis by low-pH reversed-phase liquid chromatography-tandem mass spectrometry. Online or offline instrumental configurations are also commented on, with a highlight on novel online platforms. From the articles reviewed in this period, the order of popularity of chromatographic modes for sample fractionation is affinity chromatography > size exclusion chromatography > hydrophilic interaction chromatography > high-pH reversed-phase liquid chromatography > ion exchange chromatography.

Oncoplastic mammaplasty with geometric compensation: Evolution of the technique, outcomes and follow-up in a multicentre retrospective cohort.

BACKGROUND AND OBJECTIVES: To report on the outcomes and evolution of an oncoplastic mammaplasty referred to as geometric compensation mammaplasty. METHODS: Seventy-three patients with malignant tumours were operated on and followed up in five centres in two countries. Preoperative markings were performed using a Wise pattern. The resection of affected skin was geometrically compensated using another area of preserved skin. RESULTS: Mean pathological tumour size was 30.42 ± 21.98 mm. Twenty tumours (30.77%) were locally advanced and 15 (20.55%) were multicentric. Twenty-two patients (34.38%) were submitted to neoadjuvant chemotherapy. Cosmetic results were considered good or excellent in 59 cases (80.82%). Margins were positive in two cases (2.74%). Complications were partial wound dehiscence (n = 11; 15.07%), fat necrosis (n = 9; 12.33%), skin necrosis (n = 5; 6.85%), seromas (n = 5; 6.85%), enlarged scars (n = 7; 9.59%) and infection (n = 2; 2.74%). There were three cases of local recurrence (4.29%), two of bone metastasis (2.86%) and three of metachronous contralateral breast cancer (4.35%). No deaths were recorded within a mean follow-up of 35.33 ± 28.21 months. CONCLUSIONS: The technique allowed breast conservation in situations requiring a large resection of skin in difficult positions, with a high rate of free margins, correction of ptosis, satisfactory symmetry and few complications.

Selenylated-oxadiazoles as promising DNA intercalators: Synthesis, electronic structure, DNA interaction and cleavage.

A series of selenylated-oxadiazoles were prepared and their interaction with DNA was investigated. The photophysical studies showed that all the selenylated compounds presented absorption between 270 and 329 nm, assigned to combined n→π* and π→π* transitions, and an intense blue emission (325-380 nm) with quantum yield in the range of Φ F = 0.1-0.4. DFT and TD-DFT calculations were also performed to study the likely geometry and the excited state of these compounds. Electrochemical studies revealed the ionization potential energies (-5.13 to -6.01 eV) and electron affinity energies (-2.25 to -2.83 eV), depending directly on the electronic effect (electron-donating or electron-withdrawing) of the substituent attached to the product. Finally, the UV-Vis DNA interaction experiments indicated that the compounds can interact with the DNA molecule due to intercalation, except for 3g (which interacted via electrostatic interaction). Plasmid cleavage assay presented positive results only for 3f that presented the strongest interaction results. These results made the tested selenylated-oxadiazoles as suitable structures for the development of drugs and the design of structurally-related therapeutics.

Controlling selectivity of polymer-based monolithic stationary phases.

In this work, we aimed to prepare a monolithic capillary column that allowed an isocratic separation of ten dopamine precursors and metabolites in a single run. Segments of five zwitterion sulfobetaine polymer monoliths have been modified by zwitterion phoshorylcholine by using an ultraviolet-initiated two-step photografting. Columns with 0, 33, 50, 66, and 100% of modified length were prepared. Effect of length of the modified segment and mobile phase composition has been tested. All columns provided dual-retention mechanism with reversed-phase retention in highly aqueous mobile phase and hydrophilic interaction mechanism in highly organic mobile phase. The retention mechanism was controlled by the composition of the mobile phase and has been described by a three-parameter model. We have used regression parameters to characterize the retention of analyzed compounds and to study individual pathways of dopamine metabolism. Comprehensive optimization of mobile phase composition allowed to find an optimal composition of the mobile phase and stationary phase surface chemistry arrangement to achieve desired separation. Optimized columns provided an isocratic separation of all tested compounds in less than nine min.

Mindfulness training in medical education as a means to improve resilience, empathy, and mental health in the medical profession.

The high rates of depression, burnout, and increased risk of suicide among medical students, residents, and physicians in comparison with other careers signal a mental health crisis within our profession. We contend that this crisis coupled with the inadequate acquisition of interpersonal skills during medical education results from the interaction between a challenging environment and the mental capital of individuals. Additionally, we posit that mindfulness-based practices are instrumental for the development of major components of mental capital, such as resilience, flexibility of mind, and learning skills, while also serving as a pathway to enhance empathy, compassion, self-awareness, conflict resolution, and relational abilities. Importantly, the evidence base supporting the effectiveness of mindfulness-based interventions has been increasing over the years, and a growing number of medical schools have already integrated mindfulness into their curricula. While we acknowledge that mindfulness is not a panacea for all educational and mental health problems in this field, we argue that there is currently an unprecedented opportunity to gather momentum, spread and study mindfulness-based programs in medical schools around the world as a way to address some longstanding shortcomings of the medical profession and the health and educational systems upon which it is rooted.

Epithelium-derived 6-nitrodopamine modulates noradrenaline-induced contractions in human seminal vesicles.

AIMS: To evaluate the basal release of 6-nitrodopamine (6-ND) from human isolated seminal vesicles (HISV) and to characterize its action and origin. MAIN METHODS: Left HISV obtained from patients undergoing prostatectomy surgery was suspended in a 3-mL organ bath containing warmed (37 °C) and gassed (95%O2:5%CO2) Krebs-Henseleit's solution (KHS) with ascorbic acid. An aliquot of 2 mL of the supernatant was used to quantify catecholamines by LC-MS/MS. For functional studies, concentration-responses curves to catecholamines were obtained, and pEC50 and Emax values were calculated. Detection of tyrosine hydroxylase and S100 protein were also carried out by both immunohistochemistry and fluorescence in-situ hybridization assays (FISH). KEY FINDINGS: Basal release of 6-ND was higher than the other catecholamines (14.76 ± 14.54, 4.99 ± 6.92, 3.72 ± 4.35 and 5.13 ± 5.76 nM for 6-ND, noradrenaline, adrenaline, and dopamine, respectively). In contrast to the other catecholamines, the basal release of 6-ND was not affected by the sodium current (Nav) channel inhibitor tetrodotoxin (1 µM; 10.4 ± 8.9 and 10.4 ± 7.9 nM, before and after tetrodotoxin, respectively). All the catecholamines produced concentration-dependent HISV contractions (pEC50 4.1 ± 0.2, 4.9 ± 0.3, 5.0 ± 0.3, and 3.9 ± 0.8 for 6-ND, noradrenaline, adrenaline, and dopamine, respectively), but 6-ND was 10-times less potent than noradrenaline and adrenaline. However, preincubation with very low concentration of 6-ND (10-8 M, 30 min) produced significant leftward shifts of the concentration-response curves to noradrenaline. Immunohistochemical and FISH assays identified tyrosine hydroxylase in tissue epithelium of HISV strips. SIGNIFICANCE: Epithelium-derived 6-ND is the major catecholamine released from human isolated seminal vesicles and that modulates smooth muscle contractility by potentiating noradrenaline-induced contractions.

Aesthetic results were more satisfactory after oncoplastic surgery than after total breast reconstruction according to patients and surgeons.

INTRODUCTION: Patient satisfaction after breast cancer surgery has an impact on body image, sexual function, self-esteem, and quality of life and may differ from the perception of the attending physician. This study aimed to compare the aesthetic outcomes and satisfaction with conservative oncoplastic surgeries, mastectomies, and total breast reconstruction. METHODS: We included 760 women diagnosed with invasive breast carcinoma or phyllodes tumors who returned at least 6 months after surgery or radiotherapy at two public hospitals and a private clinic between 2014 and 2022. Data was collected prospectively from patients and retrospectively from their medical records using a specific form after obtaining their informed consent. Aesthetic outcomes and quality of life were assessed using the BREAST-Q©, Harris Scale, and BCCT.core software. Data were evaluated using the SPSS statistical software. Statistical significance was set at p < 0.05. This study was approved by the hospital ethics committees. RESULTS: A total of 405 (53.29%) partial and 355 (46.71%) total reconstructions were included. Patients who underwent partial reconstruction were older and had higher body mass index. Patients who underwent total reconstruction had larger tumors with advanced clinical and pathological stages. Clinical and surgical complications occurred more frequently in the total reconstruction group. A greater number of reparative surgeries and lipofilling procedures were required for total reconstruction. According to the BREAST-Q, the partial reconstruction group showed significantly higher levels of women's satisfaction with their breasts, the surgical outcomes, psychosocial and sexual well-being, provision of information, and the reconstructive surgeon. Only physical well-being was slightly higher in the total reconstruction group. In most cases, the results were rated good or excellent. Physicians considered partial reconstructions to have better results than total reconstructions, although this difference was not perceived by the BCCT.core software. CONCLUSION: Women who underwent partial breast reconstruction had higher levels of satisfaction in several domains, lower frequency of complications, and required fewer surgeries to complete their reconstruction than women who underwent total reconstruction. Physicians were also more satisfied with the results of partial reconstructions.

Distribution of Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae) and incidence of maize rayado fino virus and Candidatus Phytoplasma asteris in corn succession planting systems.

BACKGROUND: Corn is one of the main crops grown globally to produce food for human consumption and animal feed, including raw materials for bioenergy. Effective pest management is critical for the economic viability of corn production. The leafhopper Dalbulus maidis and the diseases transmitted by it have become relevant to corn production. Our study aimed to determine environmental parameters that affect D. maidis populations and the impacts of pathogen dispersion on corn productivity under different rotation systems and sowing seasons. RESULTS: The population density of leafhoppers found in the studied crops was low but capable of establishing the diseases and spreading them widely in the crops. The leafhopper's highest occurrence was in the corn vegetative development stage, and its population peaks were earlier in the corn off-season. The incidence of maize rayado fino virus and maize bushy stunt phytoplasma were higher in corn off-season than in the growing season. The incidence of diseases was higher in the final stages of the cultivation cycle. Yield losses were significantly higher for maize bushy stunt phytoplasma and not significant for maize rayado fino virus. CONCLUSION: Our study observed that corn's physiological stage was the main factor influencing D. maidis dynamics. The occurrence of D. maidis at low densities was sufficient to ensure the efficient transmission and dissemination of maize rayado fino virus and maize bushy stunt phytoplasma, which had a higher incidence in the reproductive stage and the corn sowed off-season. © 2023 Society of Chemical Industry.

Effects of swimming training on tissue glycogen content in experimental thyrotoxic rats.

Thyrotoxicosis, a condition in which there is an excessive amount of circulating thyroid hormones, leads to reduced glycogen content in different tissues. In this study we analyzed the effects of aerobic swimming training on liver, heart, and skeletal muscle glycogen content in experimentally induced thyrotoxicosis. Wistar male rats were divided into euthyroid sedentary (ES, n = 12), euthyroid trained (ET, n = 11), thyrotoxic sedentary (TS, n = 12), and thyrotoxic trained (TT, n = 10) groups. Thyrotoxic groups received daily i.p. doses of T4 (sodium levothyroxine, 25 µg/100 g body mass) through the experimental period, and trained groups swam for 1 h at 80% of the aerobic-anaerobic transition intensity, 5 days/week for 4 weeks. Heart and liver glycogen stores were ∼30% lower in T4 treated compared with nontreated groups, but were not changed by training status. On the other hand, glycogen content in mixed fiber type gastrocnemius of TT was 1.5- to 2.3-fold greater than those in other groups, whereas no significant differences were found for the slow soleus muscle. Increased gastrocnemius but not soleus, liver, or heart glycogen indicates that in mild long-term thyrotoxicosis chronic swimming affects glycogen stores in a tissue-specific manner.

Combination of ifosfamide and etoposide as a salvage regimen for previously treated soft tissue sarcomas: a retrospective single centre study.

Introduction: Systemic treatment for metastatic soft tissue sarcoma (STS) results in modest activity in second and further lines. The aim of this study was to evaluate the efficacy of ifosfamide and etoposide (IE) as a salvage regimen for patients with metastatic STS. Methods: A retrospective, single centre study included patients with STS treated with IE from 2010 to 2018. The primary endpoint was progression-free survival (PFS). Secondary endpoints were toxicity, response rate (RR) and overall survival (OS). Survival was estimated by the Kaplan-Meier method and log-rank test used to compare the groups. Results: A total of 33 patients were identified, median age was 43 years, 60% were female, 12 had leiomyosarcoma. IE was used in second line in 51.5% and in >third line in 30.3% of patients. Median number of cycles was four and treatment discontinuation due to grade 3/4 toxicity occurred in 30.3%. The objective RR was 9% and the disease control rate was 60.6%. Median PFS was 4 months (95% CI, 2.1-5.9) and the median OS was 15 months (95% CI, 7.1-22.9). In the univariate analysis, smoking history, line of therapy and prior response to previous chemotherapy were prognostic factors for PFS. Conclusion: IE showed activity in previously treated STS, but with a non-negligible toxicity profile, worse than that with other available therapies. The use of the IE combination is not supported by our findings outside a clinical trial for soft part sarcomas.

Exercise Duration Affects Session Ratings of Perceived Exertion as a Function of Exercise Intensity.

Session ratings of perceived exertion (sRPE) are considered a practical marker of whole session exercise intensity, but its relationship to exercise volume has remained unclear. We analyzed the effects of exercise duration at different intensities on overall and differentiated sRPE. Sixteen males (Mage = 22.6, SD = 2.2 years; Mheight = 176.4, SD = 5.8 cm; Mweight = 74.0, SD = 5.9 kg; and Mbody fat = 9.4, SD = 2.2%) performed 15 and 30 minute runs at speeds associated with RPE levels of two (weak), three (moderate) and five (strong) on Borg's CR-10 scale during a previous graded exercise test. We used Foster's scale to access sRPE 30 minutes after each trial. Significant increases in sRPE were found with increases in running speed (p < 0.01, ηG2 = 0.48) and duration (p < 0.01, ηG2 = 0.16), with a significant speed X duration interaction (p < 0.01, ηG2 = 0.10). In addition, there was a significant effect for sRPE type (p = 0.01, ηG2 = 0.05) in that overall sRPE was slightly lower than sRPE differentiated to legs and higher than sRPE differentiated to breathing through the trials. Changes in sRPE from 15 to 30-minute trials were minimal for the slow speed and weak sRPE (Cohen´s dz = 0.04 - 0.25) but got higher at the moderate (Cohen´s dz = 0.88 - 1.06) and strong (Cohen´s dz = 1.94 - 2.50) speeds and sRPEs. Thus, exercise duration affects sRPE in an intensity dependent manner. This finding has practical relevance for prescribing exercise, suggesting a need to target specific training loads or aims to optimize trainees' retrospective perceptions of the exercise experience.

An estimate of the area of occupancy and population size of Brachycephalus tridactylus (Anura: Brachycephalidae) to reassess its conservation status, with a proposal for conservation measures.

BACKGROUND: We are experiencing a global crisis in conservation, which has led to the prioritization of targets, such as nations, regions, and animal groups, which are necessary while resources are disputed. Brazil is a priority not only because of its megadiversity, high rates of endemism, and frequent descriptions of new species but also because of its high levels of deforestation. Among the species groups prioritized for conservation is the anurans (Amphibia: Anura), the population of which is severely declining. One group of anurans is the genus Brachycephalus, which includes 37 endemic species in the Brazilian Atlantic Rainforest. Some of these species have highly restricted distributions (<100 ha). Thirty new species have been described since 2000, and 55.3% of all species are threatened with extinction. Brachycephalus tridactylus was only recently described and remains restricted to its type locality. Because of its reduced geographical distribution (0.41 km2), it has been proposed to be considered as Vulnerable. The objective of this study is to reevaluate the conservation status of Brachycephalus tridactylus and propose conservation measures. METHODS: We searched for new populations during 2016-2020, evaluated in loco impacts and potential impacts on the species' population, and performed an analysis of the density of this population and estimated its size. International Union for Conservation of Nature (IUCN) criteria were used to assess the conservation status of the species. RESULTS: We recorded the species in seven new localities (from 715-1,140 m above sea level) in the state of São Paulo up to 33 km from the type locality of the species (in state of Paraná). We estimated the area of occupancy as 148.44 km2, densities as one calling male per 4.05 m2 and 130.00 m2, and a total population size of 4,429,722 adult individuals. Based on our finding, we proposed three lines of management: (1) formation of fire brigades, (2) management of residents' mules in the conservation unit and surrounding areas, and (3) management of degraded areas. We recommend changing the species' conservation status from Vulnerable to Endangered because of its fragmented distribution and decline in the area of occupancy and in the quality of its habitat. Our results have expanded the species previous geographic distribution and delimited areas without previous records. Our estimates of population density and size are in accordance with those verified for congeners. The conservation of this species benefits the environments and other species that inhabit them, being, therefore, strategic for receiving conservation actions that will spread throughout the ecosystem.

A review of the diagnosis and geographical distribution of the recently described flea toad Brachycephalus sulfuratus in relation to B. hermogenesi (Anura: Brachycephalidae).

BACKGROUND: The flea toad Brachycephalus sulfuratus was recently described from southeastern and southern Brazil. In its description, the authors overlooked previous records of flea toads that had been identified as "Brachycephalus sp. nov." and B. hermogenesi occurring in the same regions, which could suggest the possibility of up to three flea toads coexisting in southern Brazil. In addition, B. sulfuratus is characterized by substantial phenotypic variability, to an extent that compromises its current diagnosis with respect to its congener B. hermogenesi. Therefore, the current state-of-affairs regarding the geographical distribution of these two species and the identification of previously known populations is hitherto uncertain. Our goals are to reassess previous records of flea toads attributable to B. hermogenesi, B. sulfuratus and "Brachycephalus sp. nov.", considering the description of B. sulfuratus, and to review the diagnosis of B. sulfuratus. METHODS: A critical analysis of the species identity of flea toad specimens attributable to B. hermogenesi, B. sulfuratus, or to a potentially undescribed species from southeastern and southern Brazil was based either on the analysis of morphology or on their advertisement calls. These analyses include our independent examinations of specimens and, when not possible, examinations of published descriptions. To allow for a consistent comparison of advertisement calls between B. hermogenesi and B. sulfuratus, we made recordings of both species, including in the type locality of the former. RESULTS: We found that morphological and call characters originally proposed as diagnostic for B. sulfuratus in relation to B. hermogenesi vary intraspecifically. Live individuals with ventral yellow spots correspond to B. sulfuratus; individuals without yellow spots can be either B. sulfuratus or B. hermogenesi. In preservative, they are indistinguishable. Previous records of Brachycephalus sp. nov. correspond to B. sulfuratus. We propose that the reduced number of notes per call and the presence of only isolated notes in the call of B. sulfuratus, as opposed to a high number of notes per call with isolated notes and note groups in the call of B. hermogenesi, as the only diagnostic characters between them. Regarding their distributions and based in our assessment, only B. sulfuratus occurs in southern Brazil, without any overlap with B. hermogenesi. There is a narrow gap between the distributions of these species around the southeast of the city of São Paulo. Our revision also revealed that some records previously attributed to B. hermogenesi in Rio de Janeiro and north São Paulo represent a distinct, unidentified flea toad that is not B. sulfuratus. Both species occur side by side in Corcovado, São Paulo, a locality from where five paratypes of B. hermogenesi were obtained. Biogeographic events that might have led to vicariance between B. hermogenesi and B. sulfuratus are discussed.

Oncoplastic Mammoplasty with disguised geometric compensation.

OBJECTIVE: To evaluate the results of a cohort of patients submitted to a new technique of oncoplastic mammoplasty, referred to as Disguised Geometric Compensation Mammoplasty (GCM), which is suitable for tumours involving the glandular tissue in the pillars of the mammoplasty. MATERIALS AND METHODS: Twenty-five breast tumours involving the pillars of the mammoplasty were included, 20 (80.0%) invasive ductal carcinomas, 3 (12.0%) phyllodes tumours, 1 (4.0%) invasive lobular carcinoma, and 1 (4.0%) in situ ductal carcinoma. Preoperative markings followed the "Wise-pattern" technique. The resection of the tumour in the pillar, preserving the overlying skin, was geometrically compensated with a corresponding area coming from the lower poles, which folded over itself and maintained the skin vascularity in the pillar. One patient was converted to classic GCM due to a positive skin margin in the frozen section. Another patient combined a Classic GCM for the inner quadrants and a Disguised GCM for the outer quadrants on the same breast. One patient decided to undergo a bilateral mastectomy after some months because of a BRCA 1 mutation. Immediate fat grafting was done in one case. Approval from the ethics committee: n. 2.322.212. RESULTS: Mean age was 47.0 ± 9.5 years. Mean clinical tumour size was 47.2 ± 22.2mm before chemotherapy and 36.7 ± 22.5mm, after. There were 11 (44.0%) locally advanced and 1 (4.00%) multicentric tumours. Nine (36.0%) were submitted to neoadjuvant chemotherapy. Adjuvant treatment was indicated according to the necessity. Ptosis was corrected in all cases. The aesthetic results were rated as excellent or good in 21 (95.5%) cases, by the Harris scale and the BCCT.core. The BREAST-Q scores for the satisfaction with the breasts and satisfaction with outcomes were 81.5 (±15.0) and 90.4 (±11.7), respectively. Intraoperative frozen sections were done in 12 (48%) cases. There was 1 (4.0%) focus of DCIS in the skin margin treated with radiotherapy. Minor complications occurred in 6 (24.0%) patients. There was 1 (4.0%) local recurrence treated with radical mastectomy, and 1 (4.0%) metastasis after 3 months. No deaths were observed within a mean follow-up time of 16.3 ± 11.4 months. CONCLUSIONS: The disguised geometric compensation mammoplasty allowed breast conservation in situations requiring large resection in the pillars of the mammoplasty, with a high rate of free margins, correction of ptosis, satisfactory symmetry, and few complications.

Influence of recovery manipulation after hyperlactemia induction on the lactate minimum intensity.

This study analyzed the influence of recovery phase manipulation after hyperlactemia induction on the lactate minimum intensity during treadmill running. Twelve male runners (24.6 +/- 6.3 years; 172 +/- 8.0 cm and 62.6 +/- 6.1 kg) performed three lactate minimum tests involving passive (LMT(P)) and active recoveries at 30%vVO(2max) (LMT(A30)) and 50%vVO(2max) (LMT(A50)) in the 8-min period following initial sprints. During subsequent graded exercise, lactate minimum speed and VO(2) in LMT(A50) (12.8 +/- 1.5 km h(-1) and 40.3 +/- 5.1 ml kg(-1) min(-1)) were significantly lower (P < 0.05) than those in LMT(A30) (13.3 +/- 1.6 km h(-1) and 42.9 +/- 5.3 ml kg(-1) min(-1)) and LMT(P) (13.8 +/- 1.6 km h(-1) and 43.6 +/- 6.1 ml kg(-1) min(-1)). In addition, lactate minimum speed in LMT(A30) was significantly lower (P < 0.05) than that in LMT(P). These results suggest that lactate minimum intensity is lowered by active recovery after hyperlactemia induction in an intensity-dependent manner compared to passive recovery.

Complexing porous polymer monoliths for online solid-phase extraction of metals in sequential injection analysis with electrochemical detection.

A monolithic column affording complexing groups was synthesized for automated solid-phase extraction of potentially toxic metal ions in a low-pressure sequential injection analyzer. Poly(glycidyl methacrylate-co-ethylene dimethacrylate) monoliths were synthesized by free-radical polymerization in the coffins of fused silica-lined stainless-steel tubes (2.10 mm i.d. × 5-6 cm length). High permeability (4.33 × 10-13 m2) was achieved for monoliths polymerized for 24 h at 60 °C from a mixture of 30 wt% glycidyl methacrylate, 10 wt% ethylene glycol dimethacrylate, 35 wt% n-propanol, 20 wt% 1,4 butanediol and 5 wt% water. Azobisisobutyronitrile (1 wt% with respect to the monomers) initiated the free-radical polymerization. These generic columns were modified with iminodiacetate to create complexing functionalities on the polymer surface, being further used for online solid-phase extraction of Cu2+, Pb2+ and Cd2+ from natural, tap and drinking waters prior to their determination by stripping chronopotentiometry. The high permeability of the column allowed the loading, washing, eluting and reconditioning steps to be made at flow rate of 10 µL s-1. The limits of detection and quantification achieved by processing 1500 µL of sample were 0.51 and 1.7 µg L-1 for Cu2+, 1.4 and 4.7 µg L-1 for Pb2+, and 1.2 and 3.8 µg L-1 for Cd2+, respectively. Recoveries were between 75.5% and 117%, obtained by quantification via external calibration curves, thus eliminating the need for the laborious standard addition strategies.

Advertisement call of Brachycephalus albolineatus (Anura: Brachycephalidae).

BACKGROUND: Brachycephalus are among the smallest terrestrial vertebrates in the world. The genus encompasses 34 species endemic to the Brazilian Atlantic Rainforest, occurring mostly in montane forests, with many species showing microendemic distributions to single mountaintops. It includes diurnal species living in the leaf litter and calling during the day, mainly during the warmer months of the year. The natural history of the vast majority of the species is unknown, such as their advertisement call, which has been described only for seven species of the genus. In the present study, we describe the advertisement call of Brachycephalus albolineatus, a recently described microendemic species from Santa Catarina, southern Brazil. METHODS: We analyzed 34 advertisement calls from 20 individuals of B. albolineatus, recorded between 5 and 6 February 2016 in the type locality of the species, Morro Boa Vista, on the border between the municipalities of Jaraguá do Sul and Massaranduba, Santa Catarina, southern Brazil. We collected five individuals as vouchers (they are from the type series of the species). We used the note-centered approach to describe the advertisement calls of the species. RESULTS: B. albolineatus have a long advertisement call of 40-191 s (mean of 88 s) composed of 8-29 notes (mean of 17 notes) emitted at a rate of 6-18 notes per minute (mean of 11 notes per minute) and at a note dominant frequency of five to seven kHz (mean of six kHz). Advertisement calls are composed of isolated notes and note groups (two notes involved in each particular note group); the former is composed by one to three pulses (mean of 2.0) and the note groups by two or three pulses in each note (mean of 2.7). Most advertisement calls present both isolated notes and note groups, with a few cases showing only the former. Note groups are emitted invariably in the last third of the advertisement call. Most isolated notes escalate their number of pulses along the advertisement call (1-2, 1-3 or 2-3). Note duration of isolated notes varies from 0.002 to 0.037 s (mean of 0.020 s) and duration of note group vary from 0.360 to 0.578 s (mean of 0.465 s). DISCUSSION: Individuals increase the complexity of their calls as they proceed, incorporating note groups and pulses per note. Intra-individual variation analysis also demonstrated that less structured advertisement calls (i.e., with notes with fewer pulses) are not stereotyped. It is possible that isolated notes and note groups could have distinct functions, perhaps territorial defense and mating, respectively. We argue that using a note-centered approach facilitates comparisons with calls of congeners, as well as underscores the considerable differences in call structure between species in a single group and among species groups.

Saddle Height and Cadence Effects on the Physiological, Perceptual, and Affective Responses of Recreational Cyclists.

Saddle height influences cycling performance and would be expected to influence cyclists physically, perceptually, and emotionally. We investigated how different saddle positions and cadences might affect cyclists' torque, heart rate, rate of perceived exertion (RPE), and affective responses (Feeling scale). Nine male recreational cyclists underwent cycling sessions on different days under different conditions with a constant load. On Day 1, the saddle was at the reference position (109% of the distance from the pubic symphysis to the ground), and on Days 2 and 3, the saddle was in the "upward position" (reference + 2.5%) and "downward position" (reference - 2.5%) in random order. Each session lasted 30 minutes and was divided into three cadence-varied 10-minute stages without interruption: (a) freely chosen cadence (FCC), (b) FCC - 20%, and (c) FCC + 20%. We assessed all dependent measures at the end of each 10 minute stage. While there was no significant interaction (Saddle × Cadence) for any of the analyzed variables, torque values were higher at lower cadences in all saddle configurations, and the FCC + 20% cadence was associated with faster heart rate, higher RPE, and lower affect compared with FCC and FCC - 20% in all saddle positions. At all cadences, the saddle at "downward position" generated a higher RPE compared with "reference position" and "upward position." The affective response was lower in the "downward position" compared with the "reference position." Thus, while cyclists perceived the downward (versus reference) saddle position as greater exercise effort, they also associated it with unpleasant affect.