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Effects of mechanical processing (MP) of corn silage and its inclusion in feedlot diets on carcass and meat quality traits of Nellore (Bos indicus) were analyzed. Seventy-two bulls aged approximately 18 months and with an initial average body weight of 392.8 ± 22.3 kg were used. The experimental design was a 2 × 2 factorial arrangement, considering the concentrate-roughage (C:R) ratio (40:60 or 20:80), MP of silage and their interactions. After slaughter, hot carcass weight (HCW), pH, temperature, backfat thickness (BFT), and ribeye area (REA), yields of meat cuts (tenderloin, striploin, ribeye steak, neck steak, and sirloin cap), meat quality traits and economic analysis were evaluated. A lower final pH was found in the carcasses of animals consuming diets containing MP versus unprocessed silage (pH = 5.81 versus 5.93). Carcass variables (HCW, BFT, and REA) and meat cut yields were not affected by treatments. The C:R 20:80 increased the intramuscular fat (IMF) content by approximately 1%, without affecting moisture, ash, and protein contents. Meat/fat color (L*, a* and b*) and Warner-Bratzler shear force (WBSF) were similar among treatments. The results indicated that the MP of corn silage in finishing diets can provide better carcass pH results in Nellore bulls, without negatively influencing carcass weight, fatness, and meat tenderness (WBSF). The IMF content of meat was slightly improved using a C:R 20:80 and lower total costs per arroba produced (3.5%), daily costs per animal/day (4.2%), and cost per ton of feeds (5.15%) were found with MP silage.
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Silagem , Zea mays , Bovinos , Animais , Masculino , Silagem/análise , Zea mays/química , Ração Animal/análise , Composição Corporal , Dieta/veterinária , CarneRESUMO
INTRODUCTION: Patients with relapsed/refractory Hodgkin lymphoma (R/R HL) experience high response rates upon anti-PD1 therapy. In these patients, the optimal duration of treatment and the risk of relapse after anti-PD1 discontinuation are unknown. METHODS: We retrospectively analyzed patients with R/R HL who responded to anti-PD1 monotherapy and discontinued the treatment either because of unacceptable toxicity or prolonged remission. A machine learning algorithm based on 17 candidate variables was trained and validated to predict progression-free survival (PFS) landmarked at the time of discontinuation of anti-PD1 therapy. RESULTS: Forty patients from 14 centers were randomly assigned to training (n = 25) and validation (n = 15) sets. At the time of anti-PD1 discontinuation, patients had received treatment for a median duration of 11.2 (range, 0-time to best response was not statistically significant in discriminating patients with PFS lesser or greater than 12 months). Considering PFS status as a binary variable (alive or dead) at a specific time point (12 months) is convenient, intuitive and allows for comparing the value of potential predicting variables in these two groups of patients. Nonetheless, this approach has two drawbacks: first, it binarizes outcome; second, it excludes patients alive with a time to last follow up lesser 12 months. Therefore, it is less powerful to demonstrate statistically significant association with PFS even if it exists 5 months. Patients discontinued anti-PD1 treatment either because of prolonged remission (N = 27, 67.5%) or unacceptable toxicity (N = 13, 32.5%). Most patients were in CR (N = 35, 87.5%) at the time of anti-PD1 discontinuation. In the training set, the machine learning algorithm identified that the most important variables to predict PFS were patients' age, time to best response, and presence or absence of CR. The performance observed in the training set was validated in the validation set. CONCLUSION: In this pilot, proof of concept study using a machine learning algorithm, we identified biomarkers capable of predicting the risk of relapse after anti-PD1 discontinuation (age, time to best response, quality of response). Once confirmed, these simple biomarkers will represent useful tools to guide the management of these patients.
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Doença de Hodgkin , Doença Crônica , Doença de Hodgkin/tratamento farmacológico , Humanos , Recidiva Local de Neoplasia/tratamento farmacológico , Intervalo Livre de Progressão , Estudos RetrospectivosRESUMO
BACKGROUND: Adult acquired flat foot deformity (AAFD) is a spectrum of conditions which can be progressive if untreated. Surgical correction and restoration of anatomical relationship are often required in the treatment of symptomatic Grade II AAFD after a failed course of conservative treatment. There is a paucity of literature recommending best practice-especially in the adult population. The authors aim to compare radiological and clinical outcomes of two widely employed surgical techniques in the treatment of symptomatic AAFD. METHODS: A retrospective study of 76 patients with Grade IIB AAFD and had undergone either lateral column lengthening (LCL) or subtalar arthroereisis (STA) surgical correction of their symptomatic AAFD. Each technique was augmented with both bony osteotomy and soft tissue transfer as determined by on table assessment. Clinical and radiological outcomes were reviewed 24 months after surgery. RESULTS: LCL and STA groups had comparable radiological outcomes at 24 months after surgery. However, LCL group demonstrated superior American Orthopaedic Foot and Ankle Society (AOFAS) midfoot (90.3 ± 12.6 vs 81.1 ± 20.6, p < 0.001) as well as Visual Analogue Scale (VAS) midfoot scores (0.5 ± 1.6 vs 1.3 ± 2.4, p < 0.001) at 24 months compared to the STA group. STA had a higher complication rate (20.6% vs 4.4%), with all cases complaining of sinus tarsi pain requiring subsequent removal of implant. CONCLUSION: There is a role for either techniques in the treatment of symptomatic AAFD. LCL whilst more invasive has demonstrated superior outcome scores and lower complication rates at 24 months compared to STA. Patients need to be counselled appropriately to appreciate the benefits of each technique.
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Pé Chato/diagnóstico por imagem , Pé Chato/cirurgia , Osteotomia/efeitos adversos , Osteotomia/métodos , Complicações Pós-Operatórias/etiologia , Próteses e Implantes/efeitos adversos , Adulto , Remoção de Dispositivo , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Dor , Complicações Pós-Operatórias/cirurgia , Estudos Prospectivos , Radiografia/métodos , Estudos Retrospectivos , Resultado do Tratamento , Escala Visual AnalógicaRESUMO
OBJECTIVE: The objective of this study is to evaluate apoptosis in hair follicles of patients with female pattern hair loss (FPHL) and its association with follicular microinflammation. METHOD: Cross-sectional study involving 17 women with FPHL and five controls. Scalp skin samples were processed for HE and TUNEL assays. The variables were compared according to the categories of follicles (terminal versus miniaturized) and groups of patients (FPHL vs. controls). RESULTS: There was a higher apoptosis index among miniaturized follicles and among the test cases (P < 0.01). Microinflammation was prominent among miniaturized follicles, especially from FPHL (P = 0.02). In addition, a positive correlation between inflammatory infiltrate and apoptosis in miniaturized follicles (rS = 0.68; P < 0.01) was found. CONCLUSIONS: Apoptosis was prominent in hair follicles from the FPHL group, as well as in miniaturized ones. Moreover, it was also correlated with the inflammatory infiltrate, which suggests that inflammation can lead to apoptosis and play a role in the pathogenesis of follicle miniaturization.
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Alopecia/patologia , Apoptose , Folículo Piloso/patologia , Inflamação/patologia , Estudos de Casos e Controles , Estudos Transversais , Feminino , Humanos , Marcação In Situ das Extremidades CortadasRESUMO
OBJECTIVE: Compare gene and protein expression for oestrogen receptor-ß (ER-ß) and progesterone receptor (PR) in facial melasma and adjacent healthy skin. METHODS: A cross-sectional study including 42 women with facial melasma, conducted at the Dermatology Service of Botucatu Medical School of São Paulo State University, Brazil. Biopsies of the melasma skin were performed, together with healthy surrounding skin. The gene expression (real-time PCR) of the hormone receptors in the tissue was evaluated. Subsequently, skin fragments were immunostained for nuclear ER-ß and PR, evaluated according to their HSCORE (epidermis) and percentage of staining per microscopic field (dermis). RESULTS: Messenger RNA tissue expression for ER-ß and PR showed no difference between melasma-affected skin fragments and the healthy perilesional areas (P > 0.2). Median nuclear epithelial expression for ER-ß and PR was higher in lesioned skin (HSCORE 157 and 58) than in the healthy perilesional skin (HSCORE 97 and 19; P < 0.01), with no difference in dermal immunostaining. Nuclear histological expression for ER-ß was associated to sun-induced melasma and negative familiar background; PR expression was associated to sun-induced melasma and darker phototypes. CONCLUSION: No difference was observed in gene expression for oestrogen-ß and progesterone receptors in melasma-affected skin compared with adjacent healthy skin. However, the higher protein expression of these receptors in melasma-affected epithelia suggests hormonal participation in the pathogenesis of this disease.
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Receptor beta de Estrogênio/metabolismo , Face , Melanose/metabolismo , Receptores de Progesterona/metabolismo , Pele/metabolismo , Adulto , Estudos Transversais , Receptor beta de Estrogênio/genética , Feminino , Humanos , Receptores de Progesterona/genéticaRESUMO
AIM: To evaluate the antibacterial, physicochemical and mechanical properties of two endodontic sealers incorporating quaternary ammonium polyethylenimine (QPEI) nanoparticles at concentrations of 1% and 2% (w/w). METHODOLOGY: The sealers tested were AH Plus and Pulp Canal Sealer EWT in the commercial unmodified form or containing 1% or 2% QPEI. Antibacterial activity was evaluated using a direct contact test (DCT) against Enterococcus faecalis ATCC 29212 and two endodontic isolates (RW35 and RN44). Sealers freshly mixed or set for 7 days were exposed to bacterial suspensions for 10, 30 and 60 min. Setting time, flow test, solubility, apparent porosity, dimensional change following setting, wettability, zeta potential and compressive strength were assessed according to the International Standard Organization 6876:2001 (ISO 6876). RESULTS: DCT results revealed that both freshly prepared sealers had antibacterial effects unaffected by QPEI incorporation. Both unmodified sealers had lost much of their antibacterial effects after 7 days. However, for Pulp Canal Sealer EWT incorporated with 1% and 2% QPEI nanoparticles, the antibacterial effects against all test E. faecalis strains within 30 and 60 min of contact were significantly greater than the unmodified formula. Addition of QPEI resulted in no significant increase in the antibacterial effects of AH Plus after ageing. As for physicochemical and mechanical tests, setting time, wettability and zeta potential were influenced by the presence of QPEI nanoparticles. CONCLUSION: Incorporation of QPEI nanoparticles can improve the long-term antibacterial activity of Pulp Canal Sealer EWT without relevant changes in physicochemical and mechanical properties.
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Antibacterianos/farmacologia , Teste de Materiais , Nanopartículas , Polietilenoimina/química , Compostos de Amônio Quaternário/química , Materiais Restauradores do Canal Radicular/química , Materiais Restauradores do Canal Radicular/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Testes de Sensibilidade MicrobianaRESUMO
This study aimed to assess the correlation between covariates of the vaginal microbiota and local levels of proinflammatory cytokines in women of reproductive age presenting four molecularly defined bacterial community-state types (CSTs). We enrolled 133 non-pregnant women who attended primary care health clinics for routine Pap-testing. Molecular profiling of vaginal microbiota was performed by V3-V4 16S rRNA sequencing. The covariates of vaginal microbiota included were: vaginal pH, total bacterial cell count, diversity (Shannon index), -richness and dominant taxa abundances. Levels of interleukin (IL)-1ß, IL-6, IL-8, and tumour necrosis factor (TNF-α) were measured by enzyme-linked immunosorbent assays in supernatants of cervicovaginal fluids. Nonparametric Kruskal-Wallis test was used to compare microbiota covariates and cytokines among different CSTs. Spearman's tests were performed to assess correlations across the measured parameters. A total of 96 (72.2%) participants had CSTs dominated by Lactobacillus spp. (Lactobacillus crispatus CST I, n=38; Lactobacillus gasseri CST II, n=20; and Lactobacillus iners CST III, n=38). A total of 37 (27.8%) presented the Lactobacillus-depleted CST IV. Total bacterial count was higher in CST II (1.29E+05, 3.40E+04-6.69E+05) compared to other Lactobacillus-dominated CSTs (p=0.0003). The highest values of microbiota diversity (1.85; 0.23-2.68) and richness (27.0; 5.0-37.0) were observed in CST IV (P<0.0001). Lower levels of IL-1ß were observed in CST I (5.4; 0.0-3,256) when compared to CST III (51.7; 0.0-2,616) and to CST IV (56.2; 0.0-3,407) (P=0.008). Levels of IL-6 were higher in CST II (4.13; 0-131.4) than in CST IV (0.0-58.27) (P=0.02). Correlation tests showed an overall distinct profile of CST II when compared to other Lactobacillusdominated CSTs, particularly regarding the correlation between total bacterial load and cytokines (r>0.39). In conclusion, this study provides evidence of a single pro-inflammatory signature of L. gasseri-dominated microbiota in response to bacterial load. Further studies evaluating a broader range of inflammation markers are warranted.
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Citocinas , Lactobacillus , Microbiota , Vagina , Vagina/imunologia , Vagina/microbiologia , Humanos , Feminino , Lactobacillus/classificação , Lactobacillus/isolamento & purificação , Adolescente , Adulto , Citocinas/análise , Citometria de Fluxo , Fatores SociodemográficosRESUMO
Extracellular matrix (ECM) proteins in the mammary gland provide structure and regulate its development and homeostasis. Alterations in its structure can regulate and support pathogenesis, like breast tumors. Aiming to identify the health and tumoral canine mammary ECM scaffold protein profile by immunohistochemistry, the decellularization process was carried out to remove the cellular content. Additionally, it was verified the influence of health and tumoral ECM on the attachment of health and tumoral cells. The types I, III, IV, and V structural collagens were scarce in the mammary tumor, and ECM fibers were disorganized. Vimentin and CD44 were more common in mammary tumor stroma, suggesting a role in cell migration that results in tumor progression. Elastin, fibronectin, laminin, vitronectin, and osteopontin were similarly detected under healthy and tumor conditions, providing the attachment of normal cells in healthy ECM, while tumoral cells were able to attach in tumoral ECM. The protein pattern demonstrates ECM alteration in canine mammary tumorigenesis, presenting new knowledge on mammary tumor ECM microenvironment.
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Proteínas da Matriz Extracelular , Neoplasias , Animais , Cães , Proteínas da Matriz Extracelular/metabolismo , Matriz Extracelular/metabolismo , Laminina , Tecido Conjuntivo , Neoplasias/patologia , Microambiente TumoralRESUMO
Non-Hodgkin lymphoma (NHL) has been associated with immunological defects, chronic inflammatory and autoimmune conditions. Given the link between immune dysfunction and NHL, genetic variants in toll-like receptors (TLRs) have been regarded as potential predictive factors of susceptibility to NHL. Adequate anti-tumoral responses are known to depend on TLR9 function, such that the use of its synthetic ligand is being targeted as a therapeutic strategy. We investigated the association between the functional rs5743836 polymorphism in the TLR9 promoter and risk for B-cell NHL and its major subtypes in three independent case-control association studies from Portugal (1160 controls, 797 patients), Italy (468 controls, 494 patients) and the US (972 controls, 868 patients). We found that the rs5743836 polymorphism was significantly overtransmitted in both Portuguese (odds ratio (OR), 1.85; P=7.3E-9) and Italian (OR, 1.84; P=6.0E-5) and not in the US cohort of NHL patients. Moreover, the increased transcriptional activity of TLR9 in mononuclear cells from patients harboring rs5743836 further supports a functional effect of this polymorphism on NHL susceptibility in a population-dependent manner.
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Linfoma não Hodgkin/genética , Polimorfismo Genético , Receptor Toll-Like 9/genética , Feminino , Genética Populacional , Humanos , Linfoma não Hodgkin/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
AIMS: To compare three decontamination methods applied to paucibacillary samples for primary isolation of Mycobacterium bovis from suspect lesions. Tuberculosis caused by Myco. bovis is an important infectious disease of cattle in Brazil and also has zoonotic potential. Although a national campaign based on testing and slaughtering cattle has achieved good results, there is a strong need to develop better diagnostic methods to identify cattle with recent infections harbouring few bacilli. METHODS AND RESULTS: A dairy herd (274 adult crossbred cows) located in the state of Rio de Janeiro was tested for tuberculosis with both single intradermal tuberculin test and comparative intradermal tuberculin test. Reactive cows (n=27, 9.8%) were slaughtered and suspect lesions were collected (one sample per cow). Samples considered paucibacillary (based on microscopy) were decontaminated with 0.75% hexadecylpyridinium chloride (HPC), 4% sodium hydroxide (Petroff) or 6% sulphuric acid. Using these methods, 10, five and six, respectively, of the 27 samples yielded positive cultures. Overall, Myco.bovis was isolated from 14 of 24 cows. Although the HPC method resulted in isolation of more Myco.bovis strains than either Petroff or sulphuric acid methods (P=0.015), it did not result in the recovery of Myco.bovis from all samples. However, using both HPC and 6% sulphuric acid methods for decontamination was possible to identify 13 of 14 (92·9%) of infected cows. CONCLUSIONS: At least two methods should be used concurrently for primary isolation of Myco. bovis from bovine tissues, particularly for paucibacillary samples. SIGNIFICANCE AND IMPACT OF THE STUDY: Detection of low numbers of Myco.bovis in tissue is an important goal in optimizing the detection of bovine tuberculosis and should assist in identification of infected cattle, in particular, those with few Myco.bovis bacilli. This was apparently the first study comparing three decontamination methods for the detection of Myco.bovis in paucibacillary samples from naturally infected cattle.
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Descontaminação/métodos , Mycobacterium bovis/isolamento & purificação , Tuberculose Bovina/diagnóstico , Animais , Bovinos , Cetilpiridínio/química , Feminino , Pulmão/microbiologia , Pulmão/patologia , Mycobacterium bovis/genética , Teste Tuberculínico , Tuberculose Bovina/microbiologiaRESUMO
BACKGROUND: The COVID-19 pandemic has created enormous challenges for the clinical management of patients with hematological malignancies (HMs), raising questions about the optimal care of this patient group. METHODS: This consensus manuscript aims at discussing clinical evidence and providing expert advice on statements related to the management of HMs in the COVID-19 pandemic. For this purpose, an international consortium was established including a steering committee, which prepared six working packages addressing significant clinical questions from the COVID-19 diagnosis, treatment, and mitigation strategies to specific HMs management in the pandemic. During a virtual consensus meeting, including global experts and lead by the European Society for Medical Oncology and the European Hematology Association, statements were discussed and voted upon. When a consensus could not be reached, the panel revised statements to develop consensual clinical guidance. RESULTS AND CONCLUSION: The expert panel agreed on 33 statements, reflecting a consensus, which will guide clinical decision making for patients with hematological neoplasms during the COVID-19 pandemic.
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COVID-19 , Neoplasias Hematológicas , Humanos , Consenso , Teste para COVID-19 , Neoplasias Hematológicas/epidemiologia , Neoplasias Hematológicas/terapia , PandemiasRESUMO
The main obstacle in the treatment of cancer patients has been resistance to multiple drugs, leading to the need to develop molecules with a higher specificity target. The liposomal formulation DODAC/2-AEH2P has antitumor potential, inducing apoptosis in several tumor types. Human chronic myeloid leukemia K-562 and K-562 Lucena (MDR+) cells were treated with the DODAC carrier and the liposomal formulation 2-AEH2P. Viability, cell cycle phases, apoptosis, marker expression and mitochondrial potential were analyzed. Significant reduction in viability was observed for all treatments. Changes in the distribution of the cell cycle phases and expression of markers involved in the apoptosis pathways were observed. Reduction of the mitochondrial electrical potential mediated by Bcl-2, being regulated by the reduction of the MTCH2 protein linked to the progression of myeloid leukemia and an increase in the pro-apoptotic proteins Bad and Bax, dependent on p53. This study demonstrated a significant therapeutic potential through apoptotic effects in leukemic cells, regardless of the molecular resistance profile (MDR+).
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Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Organofosfatos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Lipossomos/química , Lipossomos/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Ácidos Oleicos/química , Ácidos Oleicos/farmacologia , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/farmacologiaRESUMO
Food handlers, an important factor in food quality, may contain bacteria that are able to cause foodborne disease. The present study aimed to research coagulase-negative (CNS) and -positive staphylococci (CPS) in 82 food handlers, analyzing nasal and hand swabs, with identification of 62 CNS (75.6%) and 20 CPS strains (24.4%). Staphylococcal enterotoxins genes were investigated by PCR. In 20 CPS strains, 19 were positive for one or more genes. The percentage of CNS presenting genes for enterotoxins was high (46.8%). Despite of the staphylococcal species, the most common gene was sea (35.4%), followed by seh and sej (29.2%). The detection of new staphylococcal enterotoxins (SEs) genes showed a higher pathogenic potential in this genus. The presence of these gene points out the importance of CNS not only as contaminant bacteria but also as a pathogen.
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Selaginella convoluta (Arn.) Spring is a species popularly known as "jericó", and used in folk medicine as analgesic and anti-inflammatory. This study aimed to investigate in mice the antinociceptive and anti-inflammatory activities of the hexane (Sc-Hex) and chloroform (Sc-CHCl3) fractions (100, 200 and 400 mg/kg) obtained by partition of crude ethanol extract from S. convoluta. The preliminary phytochemical analysis of the fractions was performed. Antinociceptive activity was evaluated by writhing, formalin and hot-plate tests. Anti-inflammatory activity was evaluated using carrageenan-induced pleurisy. The rota-rod test was used to evaluate motor coordination. Preliminary phytochemical screening showed that the Sc-Hex and the Sc-CHCl3 were positive for the presence of flavonoids, anthracene derivatives, quinones, triterpenes and steroids. Inhibition of writhing was observed for fractions tested. The Sc-Hex at all doses tested was effective in reducing the nociceptive behavior produced by formalin only in the second phase. However, the Sc-CHCl3 decreased the paw licking time in the first and second phases. In the hot plate no significant effect was observed for any fraction. In the rota-rod test, treated mice did not demonstrate any significant motor performance changes. In the carrageenan-induced pleurisy, Sc-CHCl3 (200 mg/kg) reduced cell migration to the pleural cavity. These results reveal the antinociceptive properties of S. convoluta , which support, in part, its traditional use, since the fractions did not presented significant activity in the inflammatory response profile. We further verify that this antinociceptive effect could be by activation of nociceptive peripheral pathway.
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Selaginellaceae , Analgésicos , Animais , Anti-Inflamatórios , Carragenina , Camundongos , Dor , Extratos VegetaisRESUMO
Monthly data of abiotic variables (sea surface temperature; minimum and maximum air temperature; minimum, mean and maximum air humidity; minimum, mean and maximum atmospheric pressure; minimum, mean and maximum dew point; sea surface salinity; wind speed and direction; minimum and maximum tidal level and photosynthetically available radiation) were collected from different online repositories, all regarding the period between January 2013 and December 2017, from localities near Mar Casado Beach rocky shore, in São Paulo State southern coast, Brazil. Principal Component Analysis was performed to verify data variance and correlations among variables. Linear regression decomposition methods were applied to identify trend and seasonal patterns within the time indexed data. Deseasonalized time series were analyzed to identify structural breaks in trend patterns. Spectral analysis was applied to detrended time series.
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Chromium(VI) is present in several industrial wastewaters and it can cause health and environmental hazards above certain concentrations. Equilibrium studies have shown the feasibility of using Sargassum sp. algae for chromium removal from aqueous solutions by biosorption. However, for the design and operation of chromium biosorption processes, dynamic flow studies are required. The objective of the study was to examine chromium(VI) removal from an aqueous solution using a packed-bed column with Sargassum sp. algae as a biosorbent. The dynamic behavior of the biosorption column was investigated through experiments and the influence of operating conditions, such as initial chromium concentration, flow rate and amount of biosorbent, on the column removal capacity have been analyzed using the factorial design methodology. The capacity of removal obtained at optimum conditions was 19.06 mg of metal/g biosorbent.
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Adsorção , Cromo/isolamento & purificação , Sargassum , Brasil , Cromo/metabolismo , Análise Fatorial , Cinética , Metais Pesados/isolamento & purificação , Metais Pesados/metabolismo , Sargassum/isolamento & purificação , Sargassum/metabolismo , SoluçõesRESUMO
Casearia sylvestris Sw., popularly known in Brazil as 'guaçatonga', has been used as antitumor, antiseptic, antiulcer, local anaesthetic and healer in folk medicine. Snakebite envenomation by Bothrops jararacussu (Bjssu) constitutes a relevant public health hazard capable of inducing serious local damage in victims. This study examined the pharmacological action of apolar and polar C. sylvestris leaf extracts in reverting the neuromuscular blockade and myonecrosis, which is induced by Bjssu venom and its major toxin bothropstoxin-I on the mouse phrenic nerve-diaphragm preparations. The polar methanol extract (ME) was by far the most efficacious. ME not only prevented myonecrosis and abolished the blockade, but also increased ACh release. Such facilitation in neuromuscular transmission was observed with ME alone, but was accentuated in preparations incubated with ME plus venom or toxin. This established synergy opens an interesting point of investigation because the venom or toxin in contact with ME changes from a blocking to a facilitating effect. It is suggested that rutin, known to have potent antioxidant properties, and one of the components present in the ME, could have a role in the observed effects. Since commercial rutin did not reproduce the ME effects, it is likely that a rutin-containing phytocomplex is neutralizing the bothropic envenoming effects.
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Casearia/química , Contração Muscular/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Brasil , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Diafragma/efeitos dos fármacos , Diafragma/inervação , Diafragma/fisiologia , Técnicas In Vitro , Masculino , Metanol/química , Camundongos , Junção Neuromuscular/efeitos dos fármacos , Junção Neuromuscular/fisiologia , Extratos Vegetais/químicaRESUMO
Removal of chromium ions from aqueous solutions by using natural and crosslinked chitosan membranes was achieved using batch adsorption experiments. The effect of pH (6.0 and 2.0), concentration of chromium ions and crosslinking agents (glutaraldehyde: GLA and epichlorohydrin: ECH) on the adsorption properties of chitosan membranes was analyzed. The experimental equilibrium data was fitted to Langmuir and Freundlich models. Through the model curves, it was possible to observe that the amount of chromium ions adsorbed was significantly higher for crosslinked membranes compared to non-crosslinked chitosan. The maximum adsorbed amount was about 1400 mg g(-1) for ECH-crosslinked chitosan at pH 6.0. The adsorption rates for crosslinked chitosan membranes with glutaraldehyde and epichlorohydrin were similar for natural chitosan. Desorption study using NaCl (1 mol L(-1)) solution was performed on chitosan membranes, in order to recover chromium ions and to determine the suitable number of cycles for repeated use of these membranes without considerable decrease in their adsorption capacity. The desorption results showed that chromium ions could be more effectively removed at pH 2.0 than pH 6.0, mainly for ECH-crosslinked chitosan.