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The aim of this study was to assess the spatiotemporal variation in water quality in the Grande River and the Ondas River, in the city of Barreiras, Bahia, Brazil. Water samples were collected at 11 points along the rivers, and eight physical-chemical parameters (electrical conductivity, pH, alkalinity, apparent and true color, turbidity, dissolved oxygen, and biochemical oxygen demand) and three microbiological indicators (heterotrophic bacteria, total and thermotolerant coliforms) were analyzed. Spatiotemporal variation was assessed using the multivariate techniques of principal component analysis/factorial analysis (PCA/FA) and hierarchical cluster analysis (HCA). The results of the PCA/FA highlighted eight of the eleven parameters as the main ones responsible for the variations in water quality, with the greatest increase in these parameters being observed in the rainy season, especially among the points influenced by sewage discharges and by the influence of the urban area. The CA grouped the results from 11 points into three main groups: group 1 corresponded to points influenced by sewage discharges; group 2 grouped points with mainly urban influences; and group 3 grouped points in rural areas. These groupings showed the negative influence of urbanization and also statistically significant variations between the groups and periods. The most degraded conditions were in group 1, and the least degraded conditions were in group 3. Assessment of the variations between the monitoring periods showed that rainfall had a significant impact on the increase or decrease in the parameters assessed, as a result of surface runoff linked to urbanization and increased river flow., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The effects of the initial C/N ratio on the composting of sewage sludge and cotton residues are not reported in the literature. Understanding the main composting control parameters is essential for the good stabilization of these wastes. Therefore, this study sought to evaluate different initial C/N ratios for the composting of sewage sludge and cotton waste, aiming to find the ranges with the best performance for the process and quality of the final organic compost. In this sense, five mixtures of sewage sludge (S) and cotton residues (C) were prepared and composted with three replications for each treatment in a completely randomized design. Physicochemical parameters were evaluated during composting and in the final organic compounds. A Multivariate Principal Component Analysis (PCA) was applied to evaluate the agronomic quality of organic compounds. The thermal behaviour of the mixtures presented differences. The treatments 90C10S, 80C20S and 67C33S showed the highest EXI² index (3566.64, 3448.39 and 2738.89), longer duration of thermophilic phase (12 and 13 days) and better potential for maximum degradation (A) of organic matter (67.5, 61.2 and 65.6%C). The final compounds of 90C10S and 80C20S showed higher pH values (7.9 and 7.5) and higher CEC (123.6 and 114.0 meq/100 g OM). PCA showed similarity in the agronomic quality of organic compounds for 90C10S, 80C20S and 67C33S. The treatment 28C72S (initial C/N ratio of 16.6) presented final pH of 5.3 and did not meet the minimum limit required by Brazilian regulations. Initial C/N relations between 24.9 and 35.2 showed better stabilization of waste and final organic compound with better agronomic quality.

"Among the most common occupations, schooteachers are the ones who experience the most changes throughout their career. Considering this, the present study aims to verify whether dysphonia in three different degrees may compromise the speech intelligibility of schoolteachers in the classroom., Method: Overall, 39 students, average age 10 years, randomly selected from a public school in the Federal District, Brazil (Distrito Federal, Brasil) performed a transcription task of 20 sentences spoken by four distinct female voices in a classroom, one with a control voice (normal), another with mild dysphonia, 1 with moderate dysphonia and another with severe dysphonia. None of the voices in the study presented changes, neither in fluency nor articulation nor neurological changes. The sentences were previously recorded in an acoustically treated booth, with a microphone on a pedestal 5 cm away from the speaker's mouth. For each sentence to be recorded, the speech model was provided by the speech therapist and then repeated by the speaker according to the model. Each voice recorded 5 different sentences, phonetically balanced and with equivalent number of words. The students included in the study underwent auditory, auditory processing, sequential memory for verbal sounds and sound source location tests, fulfilling the normality criteria. They also did not have neurological or motor disorders or learning, speech or language disorders. Academic success was also taken into account. For the experiment, a speaker was placed in front of the classroom, 1 m from the wall and 1 m from the floor, and students were randomly assigned to the classroom seats. After listening to each sentence, some time was assigned for its transcription by each student., Results: The occurrence of errors was higher in voices with moderate and severe dysphonia, in which a significant difference was found (P ≤0.003) showing that voices with moderate and severe dysphonia were less intelligible than the normal voice (control voice). No difference was found between the normal voice and the mild dysphonic voice. Binary logistic regression analysis also showed that students had a 2.55 times higher chance of making mistakes with moderate dysphonic voice (P ≤0.011), and that this chance was 3.06 times greater for severe dysphonic voice (P ≤0.002) when compared to the normal voice (control voice)., Conclusion: Moderate and severe dysphonia in the voices of schoolteachers interferes with the intelligibility of students, and the greater the degree of dysphonia of the teacher, the greater the chance that the student will make intelligibility errors.", (Copyright © 2021 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Regulation of inflammation is a critical process for maintaining physiological homeostasis. The λ-carrageenan (λ-CGN) is a mucopolysaccharide extracted from the cell wall of red algae ( Chondrus crispus ) capable of inducing acute intestinal inflammation, which is translated into the production of acute phase reactants secreted into the blood circulation. However, the associated mechanisms in vertebrates are not well understood. Here, we investigated the crucial factors behind the inflammatory milieu of λ-CGN-mediated inflammation administered at 0, 1.75, and 3.5% (v/w) by i.p. injection into the peritoneal cavity of adult zebrafish (ZF) ( Danio rerio ). We found that polymorphonuclear leukocytes (neutrophils) and lymphocytes infiltrating the ZF peritoneal cavity had short-term persistence. Nevertheless, they generate a strong pattern of inflammation that affects systemically and is enough to produce edema in the cavity. Consistent with these findings, cell infiltration, which causes notable tissue changes, resulted in the overexpression of several acute inflammatory markers at the protein level. Using reversed-phase high-performance liquid chromatography followed by a hybrid linear ion-trap mass spectrometry shotgun proteomic approach, we identified 2938 plasma proteins among the animals injected with PBS and 3.5% λ-CGN. First, the bioinformatic analysis revealed the composition of the plasma proteome. Interestingly, 72 commonly expressed proteins were recorded among the treated and control groups, but, surprisingly, 2830 novel proteins were differentially expressed exclusively in the λ-CGN-induced group. Furthermore, from the commonly expressed proteins, compared to the control group 62 proteins got a significant ( p < 0.05) upregulation in the λ-CGN-treated group, while the remaining ten proteins were downregulated. Next, we obtained the major protein-protein interaction networks between hub protein clusters in the blood plasma of the λ-CGN induced group. Moreover, to understand the molecular underpinnings of these effects based on the unveiled protein sets, we performed a bioinformatic structural similarity analysis and generated overlapping 3D reconstructions between ZF and humans during acute inflammation. Biological pathway analysis pointed to the activation and abundance of diverse classical immune and acute phase reactants, several catalytic enzymes, and varied proteins supporting the immune response. Together, this information can be used for testing and finding novel pharmacological targets to treat human intestinal inflammatory diseases., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Charlie-Silva, Feitosa, Pontes, Fernandes, Nóbrega, Gomes, Prata, Ferraris, Melo, Conde, Rodrigues, Aracati, Corrêa-Junior, Manrique, Superio, Garcez, Conceição, Yoshimura, Núñez, Eto, Fernandes, Freitas, Ribeiro, Nedoluzhko, Lopes-Ferreira, Borra, Barcellos, Perez, Malafaia, Cunha, Belo and Galindo-Villegas.)

We aimed to estimate the household secondary infection attack rate (hSAR) of SARS-CoV-2 in investigations aligned with the WHO Unity Studies Household Transmission Investigations (HHTI) protocol. We conducted a systematic review and meta-analysis according to PRISMA 2020 guidelines. We searched Medline, Embase, Web of Science, Scopus and medRxiv/bioRxiv for "Unity-aligned" First Few X cases (FFX) and HHTIs published 1 December 2019 to 26 July 2021. Standardised early results were shared by WHO Unity Studies collaborators (to 1 October 2021). We used a bespoke tool to assess investigation methodological quality. Values for hSAR and 95% confidence intervals (CIs) were extracted or calculated from crude data. Heterogeneity was assessed by visually inspecting overlap of CIs on forest plots and quantified in meta-analyses. Of 9988 records retrieved, 80 articles (64 from databases; 16 provided by Unity Studies collaborators) were retained in the systematic review; 62 were included in the primary meta-analysis. hSAR point estimates ranged from 2% to 90% (95% prediction interval: 3%-71%; I 2  = 99.7%); I 2 values remained >99% in subgroup analyses, indicating high, unexplained heterogeneity and leading to a decision not to report pooled hSAR estimates. FFX and HHTI remain critical epidemiological tools for early and ongoing characterisation of novel infectious pathogens. The large, unexplained variance in hSAR estimates emphasises the need to further support standardisation in planning, conduct and analysis, and for clear and comprehensive reporting of FFX and HHTIs in time and place, to guide evidence-based pandemic preparedness and response efforts for SARS-CoV-2, influenza and future novel respiratory viruses., (© 2022 World Health Organization; licensed by John Wiley & Sons Ltd. Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.)

This study aims to demonstrate the applicability and importance of zebrafish (Danio rerio) model to study acute and chronic inflammatory responses induced by different stimuli: carrageenan phlogogen (nonimmune); acute infection by bacteria (immune); foreign body reaction (chronic inflammation by round glass coverslip implantation); reaction induced by xenotransplantation. In addition to the advantages of presenting low breeding cost, high prolificity, transparent embryos, high number of individuals belonging to the same spawning and high genetic similarity that favor translational responses to vertebrate organisms like humans, zebrafish proved to be an excellent tool, allowing the evaluation of edema formation, accumulation of inflammatory cells in the exudate, mediators, signaling pathways, gene expression and production of specific proteins. Our studies demonstrated the versatility of fish models to investigate the inflammatory response and its pathophysiology, essential for the successful development of studies to discover innovative pharmacological strategies., (Copyright © 2021. Published by Elsevier Masson SAS.)

Objective: To analyze association between social position and access to health services., Methods: This was a cross-sectional study carried out in primary health care centers in Salvador, Bahia, Brazil, where a project for improving accessibility was implemented. Pearson's chi-square test and logistic regression were used., Results: 467 users took part in the study, 75.6% had not finished high school; 78.7% had <2 minimum wages; 51.8% had intermediate/qualified occupations. Low income was associated with starting to queue at the health care center the night before or before 8 a.m. (odds ratio = 2.09 - 95%CI 1.13;3.87) and spending more time scheduling an appointment (odds ratio = 2.13 - 95%CI 1.05;4.31). Having an elementary occupation was associated with face-to-face appointment scheduling (odds ratio = 1.68 - 95%CI 1.14;2.45). Education and social trajectory showed no significant association with use of health services., Conclusion: Social inequalities in access to health services remained after the intervention to improve accessibility.

Estuaries are used by waterbirds as foraging, resting and nesting sites, serving also as shelter for migratory birds. The dynamics of this avifauna in an aquatic environment may be associated with the differences of time of day, tide height, temperature, wind speed and use of the site by different species. This study had the objective of evaluating behavioral aspects of aquatic birds, relating the influence of environmental variables with their activities. Bird counts were performed at the mouth of two important rivers of the state of Santa Catarina, Brazil, during two-hour intervals throughout the day in monthly samplings between June (2015) and May (2016). A total of 44 species were recorded, ten of which were migratory. The most recorded behaviors were foraging and resting. The Kruskal-Wallis analysis indicated no significant difference in behavior between the sampling intervals. The Bray-Curtis similarity test resulted in three groups: 1) - species that foraged most of the time; 2) - species that rested most of the time; and 3) - same time in both activities. The Indicator Species Analysis showed that 17 species were associated with only one microhabitat and 15 species with more than one. The Canonical Correlation Analysis indicated that only tide height, temperature and rainfall variables were correlated with the behaviors performed and only the resting activity was positively correlated with all variables. This may be associated with thermoregulation and the ability of some species to stay in midlitoral at high tide. The results demonstrate that different waterbird species used the studied areas in different ways. Thus, the heterogeneity of microhabitats in an aquatic environment of extreme importance for the coexistence and maintenance of the diversity of waterbirds.

The COVID-19 pandemic poses difficulties for long-term care institutions for the elderly, with increased mortality rates for the residents. This study aims to estimate the impact of COVID-19 on mortality of institutionalized elderly in Brazil. Estimates of the percentage of elderly deaths occurring in care homes were calculated for Brazil, States and Regions using estimates for the total number of deaths. The estimation was based upon information available for other countries. The weighted percentage was 44.7% and 107,538 COVID-19 deaths were estimated for the elderly in these institutions in Brazil in 2020. Higher numbers of deaths were expected in the Southeast Region (48,779 deaths), followed by the Northeast Region (28,451 deaths); São Paulo was the most affected State (24,500 deaths). The strong impact of COVID-19 on the elderly population living in long-term care facilities is clear. Estimates for the country exceeded 100,000 elderly people, potentially the most fragile and vulnerable, and are based upon a conservative number of total deaths, in view of other estimates and the alarming situation of death growth in Brazil from COVID-19.

Establishing new animal models for the study of inflammation is very important in the process of discovering new drugs, since the inflammatory event is the basis of many pathological processes. Whereas rodent models have been the primary focus of inflammation research, we defend the zebrafish (Danio rerio) test as a feasible alternative for preclinical studies. Moreover, despite all the technological development already achieved by humanity, nature can still be considered a relevant source of new medicines. In this context, the aim of this work was to evaluate the anti-inflammatory effect of a substance isolated from the medicinal plant Annona crassilfora Mart, the peltatoside, in an inflammatory model of zebrafish. It was determined: (i) total leukocyte count in the coelomate exudate; (ii) N-acetyl-β-d-glucuronidase (NAG); (iii) myeloperoxidase (MPO); (iv) and the histology of liver, intestine and mesentery. Peltotoside (25, 50 and 100 μg) and dexamethasone (25 μg) were administered intracelomatically (i.c.) 30 min before carrageenan (i.c.). Pretreatment with peltatoside at three doses significantly inhibited leukocyte recruitment in the coelomic cavity, and inhibited NAG and MPO activity against the action of Cg, in a similar manner as dexamethasone. However, some microlesions in the evaluated organs were detected. The dose of 25 μg showed an anti-inflammatory effect with lower undesirable effects in the tissues. Our results suggest that the zebrafish test was satisfactory in performing our analyzes and that the peltotoside has a modulatory action in reducing leukocyte migration., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest in relation to this study., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Excess iron (Fe) is commonly observed in wetland rice (Oryza sativa L.) plants, impairing crop growth and productivity. Some information suggests that silicon (Si) can reduce Fe content in leaves and roots of rice (vegetative phase), but nothing is known if Si could mitigate the effects of Fe toxicity on rice production and photosynthesis. Here, we assessed the role of Si in alleviating the well-known effects of Fe toxicity on nutritional imbalances, biomass accumulation, photosynthesis and grain yield using two rice cultivars having differential abilities to tolerate excess Fe. Plants were hydroponically grown under two Fe levels (25 μM or 5 mM) and the nutrient solutions were amended with Si (0 or 2 mM). Under excess Fe were detected (i) nutritional deficiencies, especially of calcium and magnesium in leaves; (ii) negligible changes in grain nutritional composition, independently of Si application; (iii) decreases in net photosynthetic rates, stomatal conductance and electron transport rate, in parallel to decreased grain yield components (total grain biomass, 1000-grain mass, percentage of filled grains, number of grains per plant and harvest index), especially in the Fe-sensitive cultivar. These impairments were partially reversed by the application of Si. Results also suggest that Si alleviated the negative impacts of Fe on spikelet sterility. In summary, we conclude that the use of Si can be recommended as an effective management strategy to reduce the negative impacts of Fe toxicity on rice photosynthetic performance and crop yield., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Iron (Fe) toxicity is often observed in lowland rice (Oryza sativa L.) plants, disrupting cell homeostasis and impairing growth and crop yields. Silicon (Si) can mitigate the effects of Fe excess on rice by decreasing tissue Fe concentrations, but no information exists whether Si could prevent the harmful effects of Fe toxicity on the photosynthesis and carbon metabolism. Two rice cultivars with contrasting abilities to tolerate Fe excess were hydroponically grown under two Fe levels (25 μM or 5 mM) and amended or not with Si (0 or 2 mM). Fe toxicity caused decreases in net photosynthetic rate (A), particularly in the sensitive cultivar. These decreases were correlated with reductions in stomatal (g s ) and mesophyll (g m ) conductances, as well as with increasing photorespiration. Photochemical (e.g. electron transport rate) and biochemical (e.g., maximum RuBisCO carboxylation capacity and RuBisCO activity) parameters of photosynthesis, and activities of a range of carbon metabolism enzymes, were minimally, if at all, affected by the treatments. Si attenuated the decreases in A by presumably reducing the Fe content. In fact, A as well as g s and g m , correlated significantly with leaf Fe contents. In summary, our data suggest a remarkable metabolic homeostasis under Fe toxicity, and that Si attenuated the impairments of Fe excess on the photosynthetic apparatus by affecting the leaf diffusive conductance with minimal impacts on carbon metabolism., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

We investigate the chemical composition and the in vitro antileishmanial and cytotoxic activities of the essential oils extracted from the leaves of Ocotea dispersa (Nees) Mez (OD-EO) and Ocotea odorifera (Vell) Rohwer (OO-EO). On the basis of GC-FID and GC-MS, α-eudesmol (20.9%), valencene (10.2%), δ-elemene (9.3%) and isospathulenol (7.3%) are the major constituents of OD-EO, whereas safrole (36.3%), γ-cadinene (6.6%), camphor (6.5%) and α-copaene (6.0%) are the main constituents of OO-EO. Both OD-EO and OO-EO display significant activity against the promastigote forms of Leishmania amazonensis , with IC 50 values of 4.67 ± 0.95 and 11.67 ± 2.16 μg/mL, respectively. The 50% cytotoxic concentration (CC 50 ) of OD-EO and OO-EO to mouse peritoneal macrophages is 26.77 ± 4.06 and 49.52 ± 1.04 μg/mL, respectively. This is the first report on the chemical composition of the essential oil extracted from the leaves of O. dispersa . Our results suggest that OD-EO and OO-EO are a promising source of new antileishmanial agents.

Recently, chitosan-based nanoparticles with mucoadhesive properties emerged as a strategy for mucosal drug release. This study aimed to characterize the interaction of mucoadhesive system chitosancoated PLGA nanoparticles (NPMA) with fish external mucus. NP suspensions with fluorescent probe were prepared and characterized by size, polydispersity, zeta potential and pH measures. In post-exposure fish were observed an increase in fluorescence imaging over time and it was significantly influenced by NPMA concentration. We also observed the main predominance the fluorescence in the spleen, followed by liver, gill and other tissues. The use of mucoadhesive nanocarriers becomes an alternative for administration of drugs and immunomodulators in immersion systems since the nanosystem can adhere to the mucosal surface of the fish with little residual effect in the water., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Leishmaniasis is an endemic disease caused by protozoa of the genus Leishmania, which affects around two million people worldwide. One major drawback in the treatment of leishmaniasis is the emergence of resistance to current chemotherapeutics. Medicinal and aromatic plants constitute a major source of natural organic compounds. In this study, the leaf essential oil of Cryptocarya aschersoniana was obtained by hydrodistillation in a Clevenger-type apparatus, and the chemical composition was analyzed by GC-MS and GC-FID. The essential oil of these species was predominantly constituted by monoterpene hydrocarbons (48.8%). Limonene (42.3%), linalool (9.7%) and nerolidol (8.6%) were the main constituents in the oil of C. aschersoniana. The in vitro activity of the oil was evaluated against the promastigote forms of Leishmania amazonensis, the causative agent of cutaneous leishmaniasis in humans. The essential oil of C. aschersoniana showed high activity against L. amazonensis promastigote forms (IC50 = 4.46 µg/mL), however, it also demonstrated a relatively high cytotoxicity on mouse peritoneal macrophages (CC50 = 7.71 µg/mL). This is the first report of the chemical composition and the leishmanicidal and cytotoxic activities of the leaf essential oil of C. aschersoniana.

The natural ligand 17β-estradiol (E2) is so far believed to induce a unique agonist-bound active conformation in the ligand binding domain (LBD) of the estrogen receptors (ERs). Both subtypes, ERα and ERβ, are transcriptionally activated in the presence of E2 with ERβ being somewhat less active than ERα under similar conditions. The molecular bases for this intriguing behavior are mainly attributed to subtype differences in the amino-terminal domain of these receptors. However, structural details that confer differences in the molecular response of ER LBDs to E2 still remain elusive. In this study, we present a new crystallographic structure of the ERβ LBD bound to E2 in which H12 assumes an alternative conformation that resembles antagonist ERs structures. Structural observations and molecular dynamics simulations jointly provide evidence that alternative ERβ H12 position could correspond to a stable conformation of the receptor under physiological pH conditions. Our findings shed light on the unexpected role of LBD in the lower functional response of ERβ subtype.

Purpose:: To evaluate the efficacy and tolerance of mycophenolate mofetil (MMF) for the treatment of noninfectious uveitis using the methods advocated by the Standardization of Uveitis Nomenclature (SUN) Working Group and to compare this with other studies of immunosuppression in ocular inflammation., Methods:: Retrospective case series. Patients with noninfectious uveitis, followed at a tertiary Uveitis Service in São Paulo, Brazil, from 2007 to 2014 and receiving oral MMF for a minimum of 6 months, were retrospectively reviewed. After reaching an optimal dose of MMF, patients were evaluated after 6 (T6), 12 (T12), and 24 months (T24). The optimal dose varied for each patient (medium 2.2 g/day, range 1.0-3.0 g/day). The main outcome measures were: 1) success on achieving complete control of inflammation in both eyes and/or oral prednisone dosage reduction to ≤10 mg per day, and 2) the length of time required to reduce oral prednisone to ≤10 mg/day, partial control of ocular inflammation, and side effects., Results:: In a cohort of 16 patients with refractory noninfectious uveitis, 67% reached the ideal prednisone dose after 1 year of MMF treatment and 83% after 2 years of MMF treatment. Complete or partial inflammation control was achieved in 43.7% at T12. Two patients (14%) had disease remission after 4.7 years of MMF treatment. Adverse effects were gastrointestinal disturbances, infection, insomnia, and liver function abnormalities at a rate of 0.03 patient-year each., Conclusions:: This small retrospective case series is consistent with the literature concerning the high efficacy and moderate tolerability of MMF in noninfectious uveitis. Observation of patients should be continued for at least 1 year to clearly determine MMF efficacy.

In this paper, we demonstrate for the first time the use of silver nanoparticles (AgNPs) for colorimetric ascorbic acid (AA) quantification in a paper-based sensor. This device is constituted by spot tests modified with AgNPs and silver ions bordered by a hydrophobic barrier which provides quantitative and fast analysis of AA. In addition, this device is employed as point-of-care monitoring using a unique drop of the sample. AgNPs paper-based sensor changed from light yellow to gray color after the addition of AA due to nanoparticle growth and clusters formation. The color intensities were altered as a function of AA concentration which were measured by either a scanner or a homemade portable transmittance colorimeter. Under the selected measurement conditions, results presented limit of detection which was comparable to analytical laboratory-based methodologies. In addition, the sensitivity of our sensor was comparable to the standard titration method when real samples were investigated., (Copyright © 2015 Elsevier B.V. All rights reserved.)

In aquaculture, activities with anesthetic compounds are usually used in order to ensure the welfare of farmed fish, allowing handling out of water with decreased trauma by stress. Presently, there is no information about anesthetic action of eugenol in early life stages of Nile tilapia (Oreochromis niloticus). The objective of this study was to evaluate different concentrations of eugenol for larvae and juveniles of Nile tilapia. Sixty animals were used for each group of weight, group I = 0.02 g; group II = 0.08 g; group III = 0.22 g; group IV = 2.62 g; and group V = 11.64 g. The eugenol concentrations tested were 50, 75, 100, 125, 150 and 175 mg L-1. No mortality was reported during the tests with eugenol. Tilapia larvae with 0.02 g and juveniles around 11.64 g can be anesthetized with eugenol concentrations between 150 and 175 mg L-1, since they determine the shortest sedation time (23 and 72 seconds, for the group of lowest and highest weights, respectively).

The presence of metals in aquatic environments has increased worldwide. Environmental assessments of metals in freshwater ecosystems presume that toxicity is mainly caused by aqueous exposure, but dietborne exposure (contaminated food) in zooplankton may occur because microalgae carry metal ions through adsorption/absorption of dissolved metal species, resulting in toxic effects once ingested by the animals. However, official regulations for ecotoxicological assays in most countries do not consider the toxic effects caused by dietborne exposure. Here, we provide life history parameters and secondary production of Simocephalus serrulatus (Koch 1841) (Cladocera: Daphniidae) fed with cadmium (Cd) contaminated algae during a 21-day bioassay. The microalgae Chlorophyceae Scenedesmus quadricauda was exposed for 96 h to dissolved Cd concentrations of 0.03; 5.87; 12.27 and 22.27 µg Cd l(-1) (equivalent to 1.6 × 10(-10); 3.2 × 10(-8); 6.7 × 10(-8); 1.2 × 10(-7) mol l(-1)) that resulted in algae internal Cd burdens of 0.004; 0.032; 0.270 and 0.280 pg Cd cell(-1), respectively. Significant toxic effects on life history parameters of S. serrulatus were observed. Time of embryonic development, generation time and age at first reproduction (primipara) showed significant delay. Length at first reproduction, number of eggs and clutches produced per female, hatching percentage, body length, survival and feeding rates were significantly reduced. Secondary production, that is, accumulated biomass for growth and reproduction, decreased significantly with dietborne Cd concentrations. Our results emphasize that food can be an important source of metals to zooplankton in aquatic ecosystems. Environmental regulations should consider the diet in ecotoxicological assessments. Furthermore, secondary production may be considered as a suitable endpoint in ecotoxicity tests.

This review article summarizes recent applications of electrochemical techniques to redox-active drug development and mechanistic studies. It includes a general introduction to the use of electrochemistry in biology, with a focus on how electrochemistry can uniquely provide both kinetic and thermodynamic information. A number of studies are reported from the literature and the authors' laboratories, including the investigation of reactive oxygen species, biooxidative/bioreductive activation of pro-drugs, and DNA alkylation, with a particular emphasis on quinones and related compounds. Data from techniques ranging from traditional cyclic voltammetry to sophisticated single cell studies are presented. The examples herein presented illustrate how electrochemical, biochemical and medical knowledge can be integrated to develop strategies for the design and development of redox-selective therapeutics.