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1.
Langmuir ; 39(14): 5002-5011, 2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-36989403

RESUMO

We report on a new iron (iii)-cyamelurate-based coordination polymer. The new material based on a heptazine derivative was prepared in aqueous medium and characterized by a variety of techniques including TGA, FTIR, XRD, HRTEM, and STEM. Due to the high structural stability of the complex in aqueous media, its heterogeneous Fenton-like catalytic activity was evaluated using a model molecule. The results obtained showed a high catalytic activity in both in basic and acid media. The pseudo-first-order rate constants normalized by iron(III) concentrations was approximately 1000 times higher than the result obtained for traditional heterogeneous catalysts based on iron(III) oxyhydroxides. The best observed catalytic activities were attributed to the increase in the binding sites of Fe3+ ions, in parallel with the increased exposure of the catalytic sites, leading to a higher atomic efficiency of the reaction.

2.
Int Urogynecol J ; 34(12): 3051-3058, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37851092

RESUMO

INTRODUCTION AND HYPOTHESIS: Dysuria is a common symptom present in several urological and gynecological conditions. Management relies on the underlying disease but may require additional symptomatic treatment. This study evaluated the combination of methenamine 250 mg and methylthioninium chloride 20 mg in the treatment of dysuria versus phenazopyridine. METHODS: This was a multicenter, single-blind, randomized, superiority clinical trial, including individuals over 18 with dysuria and a score ≥ 5 points on the pre-treatment categorical scale for pain. The primary outcome was the proportion of participants presenting excellent clinical response within 24 h after treatment. Improvement up to 72 h, time to reach improvement, sustained healing, investigators' opinion, and safety were also evaluated. RESULTS: Three hundred and fifteen participants were evaluated. Demographic characteristics and symptoms of dysuria were comparable between groups at baseline. The difference in the excellent response rate between treatments within 24 h was 12.7% (95% CI 6.16, 19.21) for pain, 9.4% (95% CI 3.32, 15.39) for burning, and 12.7% (95% CI 6.37, 18.99) for burning on urination, all in favor of the test drug, which was also superior from 36 to 48 h. Treatments were similar concerning time to reach the absence of symptoms and in the percentage of participants with sustained healing after 72 h. CONCLUSIONS: The association of methenamine with methylthioninium is superior to phenazopyridine in the treatment of dysuria.


Assuntos
Disuria , Metenamina , Humanos , Disuria/tratamento farmacológico , Disuria/etiologia , Azul de Metileno , Dor , Fenazopiridina/uso terapêutico , Método Simples-Cego , Adulto
3.
J Plant Res ; 136(5): 665-678, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37219754

RESUMO

Precipitation is an important climatic element that defines the hydrological regime, and its seasonal variation produces annual dry and wet periods in some areas. This seasonality changes wetland environments and leverages the growth dynamics of macrophytes present, including Typha domingensis Pers. This study aimed to evaluate the influence of seasonal variation on the growth, anatomy and ecophysiology of T. domingensis in a natural wetland. Biometric, anatomical and ecophysiological traits of T. domingensis were evaluated over one year at four-month intervals. Reductions in photosynthesis were evidenced at the end of the wet periods and during the dry periods, and these reductions were associated with thinner palisade parenchymas. Increased stomatal indexes and densities as well as thinner epidermis observed at the beginning dry periods can be associated with higher transpiration rates during this period. The plants maintained their water contents during the dry periods, which may be related to the storage of water in leaf trabecular parenchyma, as this is the first time that results indicate the function of this tissue as a seasonal aquiferous parenchyma. In addition, increasing proportions of aerenchymas were evident during the wet periods, which may be related to a compensation mechanism for soil waterlogging. Therefore, the growth, anatomy and ecophysiology of T. domingensis plants change throughout the year to adjust to both the dry and wet periods, providing conditions for the survival of the plants and modulating population growth.


Assuntos
Typhaceae , Estações do Ano , Crescimento Demográfico , Áreas Alagadas , Fotossíntese
4.
Molecules ; 28(4)2023 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-36838514

RESUMO

The world scenario regarding consumption and demand for products based on fossil fuels has demonstrated the imperative need to develop new technologies capable of using renewable resources. In this context, the use of biomass to obtain chemical intermediates and fuels has emerged as an important area of research in recent years, since it is a renewable source of carbon in great abundance. It has the benefit of not contributing to the additional emission of greenhouse gases since the CO2 released during the energy conversion process is consumed by it through photosynthesis. In the presented review, the authors provide an update of the literature in the field of biomass transformation with the use of niobium-containing catalysts, emphasizing the versatility of niobium compounds for the conversion of different types of biomass.


Assuntos
Combustíveis Fósseis , Nióbio , Biomassa , Fotossíntese
5.
Chem Biodivers ; 18(6): e2100094, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33860612

RESUMO

Magonia pubescens A. St.-Hil. is a Brazilian species often used in ethnopharmacology for wound and pain healing and seborrhea treatment. For the first time, essential oils (EOs) obtained from M. pubescens inflorescences were studied. The plant materials (Montes Claros, Brazil, 2018) were submitted to different gamma-radiation doses and their chemical compositions were analyzed by GC/MS and GC-FID. The cytotoxic activity of the EOs was evaluated against K562 and MDA-MB-231 cancer cell lines. A total of 30 components were identified, being 24 compounds detected for the first time in M. pubescens. The main obtained components were hotrienol (35.9 %), cis-linalool oxide (17.0 %) and trans-linalool oxide (10.2 %). The chemical composition of the EO was slightly affected by the applied radiation doses. Irradiated and non-irradiated EOs showed cytotoxic activity against both cell lines and the non-irradiated EO sample was the most active against the K562 cell lines (IC50 =22.10±1.98).


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Sapindaceae/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação
6.
J Geriatr Psychiatry Neurol ; 33(1): 22-27, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31213118

RESUMO

BACKGROUND: Insomnia complaints are frequent in Parkinson disease (PD), affecting up to 55% of patients. Factors related to insomnia in PD are multifactorial and may be associated with the degenerative process of the disease, comorbidities related to aging, and medication use. The aim of this study is to determine the factors associated with the presence of chronic insomnia in patients with PD. METHOD: A cross-sectional study was performed involving 63 consecutive patients with PD from an outpatient clinic. Participants underwent clinical interviews with neurologists and a psychiatrist and were assessed with standardized scales (Epworth Sleepiness Scale, Parkinson's Disease Questionnaire, Pittsburgh Sleep Quality Index and, for individuals with a diagnosis of restless legs syndrome(RLS)/Willis-Ekbom disease (WED), the International RLS/WED grading scale) and video-polysomnography. RESULTS: The main factors associated with chronic insomnia in PD were the habit of staying in bed without sleeping, large rapid eye movement (REM) sleep latency, high Pittsburgh Sleep Quality Index scores, and absence of obstructive sleep apnea (OSA). CONCLUSION: Insomnia in PD is related to specific factors including inadequate sleep habits, REM sleep latency, absence of OSA, and quality of sleep.


Assuntos
Doença de Parkinson/complicações , Polissonografia/métodos , Distúrbios do Início e da Manutenção do Sono/etiologia , Doença Crônica , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
7.
Ecotoxicol Environ Saf ; 193: 110336, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32092581

RESUMO

Aquatic environments contaminated by lead (Pb) are a problem in many regions of world. Since Pb has high toxicity, the identification of species for phytoremediation is important for the recovery of these areas. Thus, the phytoremediation potential of Panicum aquaticum Poir. (Poaceae) was evaluated. The anatomical and physiological responses of P. aquaticum were assessed under different concentrations of Pb [0.0, 0.5, 1.0, 2.0, 4.0, and 8.0 mM of Pb(NO3)2]. Plant growth, anatomy of roots and leaves, root uptake, root to shoot translocation, and the concentration and accumulation of Pb in organs were analyzed. Regarding leaf anatomy, Pb treatment led to changes in epidermis thickness, stomatal density, stomatal diameter, and sclerenchymal area. Endoderm thickness was increased at the highest concentrations of Pb, which may be related to reduced translocation and shoot accumulation. The roots of P. aquaticum presented increased absorption (2279 µg g-1 DW-1 of Pb). In conclusion, P. aquaticum was found to have potential for the phytoremediation of areas contaminated with Pb.


Assuntos
Chumbo/farmacocinética , Panicum/metabolismo , Poluentes Químicos da Água/farmacocinética , Biodegradação Ambiental , Chumbo/toxicidade , Panicum/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Poluentes Químicos da Água/toxicidade
8.
An Acad Bras Cienc ; 92 Suppl 1: e20190209, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32638865

RESUMO

New approaches based on image analysis can assist in phenotyping of biological characteristics, serving as support for decision-making in modern agribusiness. The aim of this study was to propose a method of high-throughput phenotyping of free access for processing of 2D X-ray images of brachiaria grass (Brachiaria ruziziensis cv. Ruziziensis) seeds, as well as correlate the parameters linked to the physiological potential of the seeds. The study was carried out by means of automated analysis of X-ray images of seeds in which a macro, called PhenoXray, was developed, responsible for digital image processing, for which a series of descriptors were obtained. After the X-ray analysis, a germination test was performed on the seeds and, from this, variables related to the physiological quality of the seeds were obtained. The use of the macro PhenoXray allowed large-scale phenotyping of seed X-rays in a simple, rapid, robust, and totally free manner. This study confirmed that the methodology is efficient for obtaining morphometric data and tissue integrity data in Brachiaria ruziziensis seeds and that parameters such as relative density, integrated density, and seed filling are closely related to the physiological attributes of seed quality.


Assuntos
Brachiaria , Germinação , Sementes , Raios X
9.
Psychiatry Clin Neurosci ; 73(5): 248-253, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30636105

RESUMO

AIM: Sleep disorders can be associated with an increased risk for cognitive decline in patients with Parkinson's disease (PD). The aim of this study was to examine the association between cognitive status and presence of sleep symptoms and sleep disorders in PD patients. METHODS: We evaluated excessive sleepiness, other sleep symptoms, and performed polysomnography and neuropsychological evaluation in 79 patients. They were classified as having normal cognition (PDNC), mild cognitive impairment (PDMCI), or dementia (PDD). RESULTS: There were 29 PDNC, 39 PDMCI, and 11 PDD patients. PDD patients were older, had higher scores on the Unified Parkinson's Disease Rating Scale, and lower Schwab and England Activities of Daily Living scores than PDNC patients. After analysis of the polysomnographic variables, it was also found that PDD patients had a lower sleep efficiency, lower total sleep time, and lower number of sleep state changes than PDNC patients. In a stepwise analysis, defining Mattis Dementia Rating Scale scores as the dependent variable, the results were a model that selected three variables that accounted for 59% of the variation in the Mattis Dementia Rating Scale score: wake time after sleep onset, number of state changes, and schooling. CONCLUSION: We found a significant association between global cognitive performance and wake time after sleep onset and the number of state changes during sleep measured in the polysomnography of PD patients. However, we did not find any other association between sleep disorders or symptoms and cognitive status or cognitive performance of PD patients.


Assuntos
Disfunção Cognitiva/etiologia , Demência/etiologia , Doença de Parkinson/complicações , Transtornos do Sono-Vigília/etiologia , Idoso , Disfunção Cognitiva/epidemiologia , Comorbidade , Estudos Transversais , Demência/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/epidemiologia , Polissonografia , Transtornos do Sono-Vigília/diagnóstico , Transtornos do Sono-Vigília/epidemiologia
10.
Neurobiol Learn Mem ; 155: 92-103, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29964163

RESUMO

Although the functional role for newborn neurons in neural circuits is still matter of investigation, there is no doubt that neurogenesis modulates learning and memory in rodents. In general, boosting neurogenesis before learning, using genetic-target tools or drugs, improves hippocampus-dependent memories. However, inhibiting neurogenesis may yield contradictory results depending on the type of memory evaluated. Here we tested the hypothesis that inhibiting constitutive neurogenesis would compromise social recognition memory (SRM). Male Swiss mice were submitted to three distinct procedures to inhibit neurogenesis: (1) intra-cerebral infusion of Cystosine-ß-D-Arabinofuranoside (AraC); (2) intra-peritoneal injection of temozolomide (TMZ) and (3) cranial gamma irradiation. All three methods decreased cell proliferation and neurogenesis in the dentate gyrus of the dorsal (dDG) and ventral hippocampus (vDG), and the olfactory bulb (OB). However, the percentage inhibition diverged between methods and brain regions. Ara-C, TMZ and gamma irradiation impaired SRM, though only gamma irradiation did not cause side effects on weight gain, locomotor activity and anxiety. Finally, we examined the contribution of cell proliferation in vDG, dDG and OB to SRM. The percent of inhibition in the dDG correlates with SRM, independently of the method utilized. This correlation was observed for granular cell layer of OB and vDG, only when the inhibition was induced by gamma irradiation. Animal's performance was restrained by the inhibition of dDG cell proliferation, suggesting that cell proliferation in the dDG has a greater contribution to SRM. Altogether, our results demonstrate that SRM, similarly to other hippocampus-dependent memories, has its formation impaired by reducing constitutive neurogenesis.


Assuntos
Proliferação de Células/fisiologia , Hipocampo/fisiologia , Memória de Longo Prazo/fisiologia , Neurogênese/fisiologia , Bulbo Olfatório/fisiologia , Reconhecimento Psicológico/fisiologia , Percepção Social , Animais , Antineoplásicos Alquilantes/farmacologia , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Comportamento Animal/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Glicosídeo Hidrolases/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/efeitos da radiação , Masculino , Memória de Longo Prazo/efeitos dos fármacos , Memória de Longo Prazo/efeitos da radiação , Camundongos , Neurogênese/efeitos dos fármacos , Neurogênese/efeitos da radiação , Bulbo Olfatório/efeitos dos fármacos , Bulbo Olfatório/efeitos da radiação , Lesões Experimentais por Radiação , Reconhecimento Psicológico/efeitos dos fármacos , Reconhecimento Psicológico/efeitos da radiação , Temozolomida/farmacologia
11.
Environ Monit Assess ; 190(8): 473, 2018 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-30022338

RESUMO

An analytical liquid-liquid extraction-gas chromatography-mass spectrometry (LLE-GC-MS) method was developed and validated for the determination of trihalomethanes (THMs) in environmental samples. The compounds studied were trichloromethane (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and tribromomethane (TBM). The calibration curves for the THMs showed high linearity in the range of 1-1000 µg L-1. Studies of intra-day and inter-day precision, limit of detection (LOD), limit of quantification (LOQ), accuracy, and recovery were performed with low (10 µg L-1), medium (40 µg L-1), and high (200 µg L-1) concentrations of THMs. The intra-day and inter-day precision RSD varied in the ranges of 0.17-6.95% and 0.26-15.70%, respectively. No statistical differences were observed between the analysis of the concentration of certified reference materials (CRM 4M8140-U) and the values reported by CRM, indicating the good accuracy of the proposed method. The recovery was 88.75-119.21%. The LOD and LOQ were smaller than 0.13 and 0.40 µg L-1. Compared with reported LLE-GC-MS methods, the validated method had similar LOD and enhanced LOQ, precision, accuracy, and recovery. Also, the method is robust, selective to THMs, and the total time for the extraction and GC separation of THMs is about 18 min. The method was useful for detecting and quantifying low concentrations of TCM (40-80 µg L-1) formed by water chlorination in the presence of Microcystis aeruginosa cyanobacteria, thus demonstrating its applicability for monitoring THMs in real samples.


Assuntos
Monitoramento Ambiental/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Extração Líquido-Líquido/métodos , Trialometanos/análise , Poluentes Químicos da Água/análise , Clorofórmio/análise , Halogenação , Microcystis/metabolismo , Água/química
12.
Eur Neurol ; 78(5-6): 330-337, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29084403

RESUMO

OBJECTIVES: To determine the frequency of major sleep disorders in patients with Parkinson's disease (PD), diagnosed according to the third international classification of sleep disorders, and assess the relationship of those disorders with the quality of life. METHODS: A cross-sectional study was performed involving 88 consecutive patients with PD from outpatient clinic. Participants were subjected to clinical interviews, assessment using standardized scales (Epworth Sleepiness Scale, PD Questionnaire, Pittsburgh sleep quality index (PSQI) and, for individuals with a diagnosis of RLS/WED, International RLS/WED grading scale), and video-polysomnography. RESULTS: We observed sleep disorders in 96.5% of the participants, with REM-sleep behavior disorder found in 62.5%, obstructive sleep apnea in 62.5%, insomnia in 55.7%, and restless legs syndrome in 28.4%. We observed a correlation between health-related quality of life with the PSQI and the Epworth sleepiness scale. CONCLUSION: Patients with PD have a high prevalence of sleep disorders. The quality of sleep and excessive daytime sleepiness significantly affect the quality of life in these individuals.


Assuntos
Doença de Parkinson/complicações , Qualidade de Vida , Transtornos do Sono-Vigília/epidemiologia , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Prevalência , Transtornos do Sono-Vigília/etiologia , Inquéritos e Questionários
13.
J Phys Chem A ; 119(21): 5241-9, 2015 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-25629880

RESUMO

Glyphosate (N-(phosphonomethyl)glycine) (Gph) is a herbicide that is broadly used in several countries. Its application to eliminate weeds may have the undesired effect of diminishing the metallic cations found in the soil (e.g., Ni(2+) and Zn(2+)), due to a complexation reaction that depends on the soil's pH. To better understand the molecular structures of glyphosate that are involved in such a complexation reaction, we have studied all possible glyphosate conformations in aqueous solution that may be involved in deprotonation reactions in the pH range from 2 to 11 using the polarizable continuum method (PCM). We have also compared direct (or absolute) methods to calculate pKa values, the cluster-continuum model and the proton-exchange scheme, using different thermodynamic cycles. The best result was achieved when using a proton-exchange scheme, which was able to properly reproduce three glyphosate experimental pKa values predicted for the glyphosate structures and conformations previously determined.


Assuntos
Glicina/análogos & derivados , Prótons , Água/química , Cátions/química , Gases/química , Glicina/química , Herbicidas/química , Concentração de Íons de Hidrogênio , Modelos Químicos , Estrutura Molecular , Solo/química , Soluções , Eletricidade Estática , Termodinâmica , Glifosato
14.
Sleep Breath ; 19(3): 997-1002, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25566939

RESUMO

OBJECTIVE AND BACKGROUND: Excessive fragmentary myoclonus (EFM) is characterized by subtle arrhythmic and excessive jerks that are usually asymmetric and asynchronous. EFM occurs in different areas of the body, mainly the face and distal parts of the arms and legs, and is detected by surface electromyography during sleep. The present study aimed to determine the prevalence of EFM in Parkinson's disease (PD) patients at a tertiary level outpatient clinic as well as to describe the clinical and polysomnographic profiles of these patients. METHODS: A total of 62 consecutive PD patients were included in the study. Patients were evaluated using the Brazilian version of the PD Sleep Scale, Portuguese Language version of Epworth's Daytime Sleepiness Scale validated for Brazilian population, Brazilian Portuguese version of PD Quality of Life Scale, and Global Deterioration Scale. Evaluation of the sleep disorders was performed by clinical interview and polysomnography. RESULTS: EFM was found in 62.7% of PD patients. EFM was found to be associated with obstructive sleep apnea syndrome and advanced age. CONCLUSIONS: EFM occurs in a significantly high proportion of PD patients and is related to obstructive sleep apnea syndrome (OSAS) and advanced age, so EFM should be systematically investigated by polysomnography (PSG) in PD patients.


Assuntos
Síndrome da Mioclonia Noturna/diagnóstico , Síndrome da Mioclonia Noturna/epidemiologia , Doença de Parkinson/diagnóstico , Doença de Parkinson/epidemiologia , Polissonografia , Fatores Etários , Idoso , Instituições de Assistência Ambulatorial , Brasil , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/epidemiologia
15.
An Acad Bras Cienc ; 86(3): 1423-33, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25211112

RESUMO

This study aimed at verifying the lead tolerance of water hyacinth and at looking at consequent anatomical and physiological modifications. Water hyacinth plants were grown on nutrient solutions with five different lead concentrations: 0.00, 0.50, 1.00, 2.00 and 4.00 mg L-1 by 20 days. Photosynthesis, transpiration, stomatal conductance and the Ci/Ca rate were measured at the end of 15 days of experiment. At the end of the experiment, the anatomical modifications in the roots and leaves, and the activity of antioxidant system enzymes, were evaluated. Photosynthetic and Ci/Ca rates were both increased under all lead treatments. Leaf anatomy did not exhibit any evidence of toxicity effects, but showed modifications of the stomata and in the thickness of the palisade and spongy parenchyma in the presence of lead. Likewise, root anatomy did not exhibit any toxicity effects, but the xylem and phloem exhibited favorable modifications as well as increased apoplastic barriers. All antioxidant system enzymes exhibited increased activity in the leaves, and some modifications in roots, in the presence of lead. It is likely, therefore, that water hyacinth tolerance to lead is related to anatomical and physiological modifications such as increased photosynthesis and enhanced anatomical capacity for CO2 assimilation and water conductance.


Assuntos
Eichhornia/efeitos dos fármacos , Chumbo/farmacologia , Fotossíntese/efeitos dos fármacos , Eichhornia/anatomia & histologia , Eichhornia/classificação , Eichhornia/fisiologia , Folhas de Planta/citologia , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos
16.
Environ Sci Pollut Res Int ; 31(28): 41059-41068, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38842777

RESUMO

Lead (Pb) can be deposited in aquatic environments that are especially subject to pollution due to wastewater and sewage disposal. This study aimed to evaluate the tolerance of Echinodorus grandiflorus (Cham. & Schltr.) Micheli to Pb and changes in growth, gas exchange, and leaf anatomy. Experiments were conducted with E. grandiflorus plants exposed to the following Pb concentrations in nutrient solution: [0; 0.75; 1.5; 3.0 and 9.0 µM Pb (NO 3)2] in a greenhouse for 60 days. At the end of the experiment, the lead concentration, growth, leaf gas exchange, and changes in leaf anatomy were evaluated. There was no mortality of E. grandiflorus plants, and they accumulated higher concentrations of Pb proportional to the concentration of the pollutant in the solution. Pb did not cause significant changes in growth, stomatal conductance, transpiration, and Ci/Ca rate but reduced the photosynthesis in E. grandiflorus. The leaf anatomy showed significant changes in the presence of Pb, reducing the epidermis and chlorophyll parenchyma. E. grandiflorus demonstrated tolerance to Pb, surviving and growing under contamination; however, it negatively modified its leaf anatomy and photosynthesis in the presence of the metal.


Assuntos
Chumbo , Folhas de Planta , Folhas de Planta/anatomia & histologia , Folhas de Planta/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Alismataceae/anatomia & histologia
17.
Org Biomol Chem ; 11(2): 299-308, 2013 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-23172415

RESUMO

The origin of the anomeric effect has remained an open question. After Mo demonstrated that hyperconjugation is not responsible for the anomeric effect [Y. Mo, Nature Chem., 2010, 2, 666.], electrostatic interactions and Pauli repulsions have been at the center of this debate. In this work, the total energies of the most stable rotamers of the equatorial and axial anomers of fluoro, hydroxyl, cyano and amino groups in cyclohexane and 2-substituted tetrahydropyran rings are decomposed into their fundamental kinetic, electrostatic and exchange components. In this partitioning scheme, the differences in the total energies among the most stable rotamers of each anomer correlate very well with the differences in the exchange components, revealing that the anomeric effect has no electrostatic origin. Indeed, the anomeric effect is dominated by the exchange energy. This proposal for the origin of the anomeric effect brings new insights that, once incorporated, may improve qualitative chemical models. Implications of this new proposal for the origin of the anomeric effect on geometric parameters and solvation are also discussed.


Assuntos
Cicloexanos/química , Piranos/química , Elétrons , Isomerismo , Conformação Molecular , Soluções , Solventes/química , Eletricidade Estática , Termodinâmica
18.
Environ Sci Pollut Res Int ; 29(13): 19878-19889, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35080729

RESUMO

Typha domingensis Pers. is a plant that grows in marshy environments, where cadmium (Cd) accumulates. The root is the first organ that comes into contact with the metal. The aim of this study was to evaluate the effect of Cd on the roots of T. domingensis. The experiment was conducted in a greenhouse using different Cd concentrations: (1) 0 µM (control), (2) 10 µM, and (3) 50 µM, with 10 replicates for 90 days. The plants were placed in plastic containers containing 5 L of nutrient solution modified with the different Cd concentrations. At the end of the experiment, the roots were measured, sampled, fixed, and subjected to usual plant microtechniques. The slides were observed and photographed under light microscopy and analyzed in ImageJ software. To measure Cd absorption, atomic-absorption spectrometry was used. The data were subjected to analysis of variance and comparison of means by the Scott-Knott test at P < 0.05. When exposed to 50 µM of Cd, the roots accumulated 99.35% of the Cd. At this concentration, there was a reduction in the exodermis but there was an increase in the diameter of the cortical cells and in the proportion of aerenchyma in the cortex. There was an increase in the root cap, which guaranteed the protection of the primary meristems. Therefore, T. domingensis adjusts its root anatomy improving the Cd tolerance and shows potential for phytoremediation purposes.


Assuntos
Typhaceae , Biodegradação Ambiental , Cádmio/análise , Raízes de Plantas/química , Plantas , Áreas Alagadas
19.
Protoplasma ; 258(4): 765-777, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33404920

RESUMO

Radial oxygen loss is a physical phenomenon that occurs naturally in aquatic plants. Typha domingensis was chosen as a model plant because it possesses basic morphological characteristics, such as a stem (rhizome) that produces leaves and adventitious roots, which are present in many aquatic plants. This study aimed to evaluate the following: the relevance of the anatomy of T. domingensis on gas diffusion among organs; the influence of plant parts on radial oxygen loss; the role of catalase in radial oxygen loss; and the proposition of a novel explanation for the downward diffusion of oxygen through the organs of this aquatic macrophyte and into the environment. Typha domingensis plants were cultivated in a greenhouse under different conditions: plants with intact leaves, plants with leaves cut in half, and plants without leaves. Furthermore, we evaluated the percentage of aerenchyma in different vegetative organs, the minimum pressure required for radial oxygen loss, the daily variations of dissolved oxygen, and the roots' catalase activity. The results demonstrated that certain cellular features contributed to decreased oxygen diffusion among the organs, specifically, those found in the leaf-rhizome and root-rhizome interfaces as well as the suberin and lignin layers in these regions. Additionally, our experiments with a catalase activator and inhibitor validated that a significant amount of the oxygen released in radial oxygen loss could not, in fact, be exclusively supplied by the atmosphere. Thus, a complementary model is proposed in which catalase activity is an important component of radial oxygen loss.


Assuntos
Typhaceae , Catalase , Oxigênio , Folhas de Planta , Raízes de Plantas
20.
Front Plant Sci ; 12: 631768, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33719306

RESUMO

Soybean is one of the most valuable commercial crops because of its high protein, carbohydrate, and oil content. The land area cultivated with soybean in subtropical regions, such as Brazil, is continuously expanding, in some instances at the expense of carbon storing natural habitats. Strategies to decrease yield/seed losses and increase production efficiency are urgently required to meet global demand for soybean in a sustainable manner. Here, we evaluated the effectiveness of an Ascophyllum nodosum extract (ANE), SealicitTM, in increasing yields of different soybean varieties, in two geographical regions (Canada and Brazil). In addition, we investigated the potential of SealicitTM to reduce pod shattering at the trials in Brazil. Three different concentrations of SealicitTM were applied to pod shatter-susceptible (SS) UFUS 6901 and shatter-resistant (SR) UFUS 7415 varieties to assess their impact on pod firmness. SS variety demonstrated a significant decrease in pod shattering, which coincided with deregulation of GmPDH1.1 and GmSHAT1-5 expression, genes that determine pod dehiscence, and higher seed weight per pod. SealicitTM application to the SR variety did not significantly alter its inherent pod shatter resistance, but provided higher increases in seed yield at harvest. This yield increase maybe associated with to other yield components stimulated by the biostimulant. This work demonstrates that SealicitTM, which has previously been shown to improve pod firmness in Arabidopsis and selected commercial oilseed rape varieties through IND gene down-regulation, also has the potential to improve pod resistance and seed productivity in soybean, a member of the legume family sharing a similar strategy for seed dispersal.

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