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1.
Small ; 20(21): e2308594, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38152974

RESUMO

The development of catalysts for an economical and efficient oxygen evolution reaction (OER) is critical for clean and sustainable energy storage and conversion. Nickel-iron-based (NiFe) nanostructures are widely investigated as active OER catalysts and especially shape-controlled nanocrystals exhibit optimized surface structure and electronic properties. However, the structural control from amorphous to well-defined crystals is usually time-consuming and requires multiple stages. Here, a universal two-step precipitation-hydrothermal approach is reported to prepare a series of NiFe-based nanocrystals (e.g., hydroxides, sulfides, and molybdates) from amorphous precipitates. Their morphology and evolution of atomic and electronic structure during this process are studied using conclusive microscopy and spectroscopy techniques. The short-term, additive-free, and low-cost method allows for the control of the crystallinity of the materials and facilitates the generation of nanosheets, nanorods, or nano-octahedra with excellent water oxidation activity. The NiFe-based crystalline catalysts exhibit slightly compromised initial activity but more robust long-term stability than their amorphous counterparts during electrochemical operation. This facile, reliable, and universal synthesis method is promising in strategies for fabricating NiFe-based nanostructures as efficient and economically valuable OER electrocatalysts.

2.
Eur J Appl Physiol ; 123(5): 989-1001, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36617359

RESUMO

PURPOSE: The geometric patterns of ventricular remodeling are determined using indexed left ventricular mass (LVM), end-diastolic volume (LVEDV) and concentricity, most often measured using the mass-to-volume ratio (MVR). The aims of this study were to validate lean body mass (LBM)-based allometric coefficients for scaling and to determine an index of concentricity that is independent of both volume and LBM. METHODS: Participants from the UK Biobank who underwent both CMR and dual-energy X-ray absorptiometry (DXA) during 2014-2015 were considered (n = 5064). We excluded participants aged ≥ 70 years or those with cardiometabolic risk factors. We determined allometric coefficients for scaling using linear regression of the logarithmically transformed ventricular remodeling parameters. We further defined a multiplicative allometric relationship for LV concentricity (LVC) adjusting for both LVEDV and LBM. RESULTS: A total of 1638 individuals (1057 female) were included. In subjects with lower body fat percentage (< 25% in males, < 35% in females, n = 644), the LBM allometric coefficients for scaling LVM and LVEDV were 0.85 ± 0.06 and 0.85 ± 0.03 respectively (R2 = 0.61 and 0.57, P < 0.001), with no evidence of sex-allometry interaction. While the MVR was independent of LBM, it demonstrated a negative association with LVEDV in (females: r = - 0.44, P < 0.001; males: - 0.38, P < 0.001). In contrast, LVC was independent of both LVEDV and LBM [LVC = LVM/(LVEDV0.40 × LBM0.50)] leading to increased overlap between LV hypertrophy and higher concentricity. CONCLUSIONS: We validated allometric coefficients for LBM-based scaling for CMR indexed parameters relevant for classifying geometric patterns of ventricular remodeling.


Assuntos
Bancos de Espécimes Biológicos , Remodelação Ventricular , Masculino , Humanos , Feminino , Modelos Lineares , Reino Unido , Índice de Massa Corporal , Hipertrofia Ventricular Esquerda
3.
Clin Oral Investig ; 27(11): 6513-6521, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37725169

RESUMO

OBJECTIVES: To compare the prevalence of gingivitis estimated by the 2018 European Federation of Periodontology/American Academy of Periodontology (EFP/AAP) classification with the other case definitions and assess the ability of this classification system in discriminating sociodemographic and clinical factors associated with the presence of gingivitis in a cohort study. MATERIALS AND METHODS: A multistage random sample of 1134 12-year-old adolescents was submitted to a full-mouth examination according to the Community Periodontal Index. Socioeconomic and clinical variables were collected at baseline. Gingivitis was considered according to the following criteria: (a) ≥ 10% of bleeding sites (the 2018 EFP/AAP criteria); (b) ≥ 15% of bleeding sites; and (c) the mean full-mouth bleeding sites. Adjusted multilevel Poisson regression assessed the association between independent variables at baseline and each definition of gingivitis at 2-year follow-up. RESULTS: Seven hundred forty-two 14-year-old adolescents were re-revaluated at follow-up. The prevalence of gingivitis was 28.7% according to 10% of bleeding threshold. The 2018 EFP/AAP criteria and other definitions showed higher prevalence and mean of gingivitis for low-household income adolescents and for those with higher levels of dental plaque and untreated dental caries. Nonetheless, the highest strengths of association were observed for the threshold of ≥ 15% of bleeding sites. CONCLUSION: The 2018 EFP/AAP case definition of gingivitis showed a similar discriminant validity compared to the 15% threshold and the mean full-mouth bleeding sites. CLINICAL RELEVANCE: The 2018 EFP/AAP classification allows the discrimination of important risk factors and should be used for the establishment of priorities for large-scale therapeutic programs.


Assuntos
Cárie Dentária , Gengivite , Humanos , Adolescente , Estudos de Coortes , Periodontia , Índice Periodontal , Hemorragia Bucal
4.
Anal Chem ; 94(44): 15223-15230, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36302263

RESUMO

Combining spectroscopic techniques with electrochemistry is a promising strategy, as it allows the detailed investigation of the species that are consumed and produced by the reaction in real time. However, as with any in situ coupling technique, the junction between NMR and electrochemistry presents some challenges, notably the distortion of NMR signals due to the placement of electrodes close to or within the detection region. In this work, miniaturized electrodes made of carbon fiber paper were developed and later modified with platinum. Platinum decoration by cathodic deposition was chosen, as platinum is a prominent element in electrocatalysis, able to catalyze a large variety of reactions. To evaluate the efficiency of this electrochemical system, the oxidation of ascorbic acid was used as a model reaction. It was observed that the electrodes caused substantial signal distortion when placed within the detection region (full width at half-maximum equal to 1.46 Hz), whereas no distortion was observed when the electrodes were placed 1 mm above the detection region (full width at half-maximum equal to 0.95 Hz). With this system, it was also possible to monitor the magnetoelectrolysis effect, caused by the interaction of the magnetic field with the flowing ions, leading to a doubling of the ascorbic acid oxidation rate, compared to the reaction performed without a magnetic field. In addition to its low cost and simplicity in preparation, the developed electrode system allows the electrode surface to be easily modified with other suitable catalysts.


Assuntos
Ácido Ascórbico , Platina , Microeletrodos , Fibra de Carbono , Platina/química , Eletrodos , Eletroquímica , Oxirredução , Carbono/química
5.
N Engl J Med ; 388(26): 2456-2465, 2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37379136
6.
N Engl J Med ; 389(13): 1252, 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37754302
7.
Brain Behav Immun ; 92: 90-101, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33242651

RESUMO

The mitochondrial pyruvate carrier (MPC) is an inner-membrane transporter that facilitates pyruvate uptake from the cytoplasm into mitochondria. We previously reported that MPC1 protein levels increase in the hypothalamus of animals during fever induced by lipopolysaccharide (LPS), but how this increase contributes to the LPS responses remains to be studied. Therefore, we investigated the effect of UK 5099, a classical MPC inhibitor, in a rat model of fever, on hypothalamic mitochondrial function and neuroinflammation in LPS-stimulated preoptic area (POA) primary microcultures. Intracerebroventricular administration of UK 5099 reduced the LPS-induced fever. High-resolution respirometry revealed an increase in oxygen consumption and oxygen flux related to ATP synthesis in the hypothalamic homogenate from LPS-treated animals linked to mitochondrial complex I plus II. Preincubation with UK 5099 prevented the LPS-induced increase in oxygen consumption, ATP synthesis and spare capacity only in complex I-linked respiration and reduced mitochondrial H2O2 production. In addition, treatment of rat POA microcultures with UK 5099 reduced the secretion of the proinflammatory and pyrogenic cytokines TNFα and IL-6 as well as the immunoreactivity of inflammatory transcription factors NF-κB and NF-IL6 four hours after LPS stimulation. These results suggest that the regulation of mitochondrial pyruvate metabolism through MPC inhibition may be effective in reducing neuroinflammation and fever.


Assuntos
Peróxido de Hidrogênio , Transportadores de Ácidos Monocarboxílicos , Animais , Febre/induzido quimicamente , Lipopolissacarídeos , Mitocôndrias , Ácido Pirúvico , Ratos
8.
Mem Inst Oswaldo Cruz ; 115: e200328, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33111750

RESUMO

Scientists have increasingly recognised that low methodological and analytical rigour combined with publish-or-perish incentives can make the published scientific literature unreliable. As a response to this, large-scale systematic replications of the literature have emerged as a way to assess the problem empirically. The Brazilian Reproducibility Initiative is one such effort, aimed at estimating the reproducibility of Brazilian biomedical research. Its goal is to perform multicentre replications of a quasi-random sample of at least 60 experiments from Brazilian articles published over a 20-year period, using a set of common laboratory methods. In this article, we describe the challenges of managing a multicentre project with collaborating teams across the country, as well as its successes and failures over the first two years. We end with a brief discussion of the Initiative's current status and its possible future contributions after the project is concluded in 2021.


Assuntos
Pesquisa Biomédica/tendências , Projetos de Pesquisa , Brasil , Reprodutibilidade dos Testes
9.
J Food Sci Technol ; 57(3): 971-979, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32123418

RESUMO

The aim of study was evaluate the effect of using rice protein coating with different plasticizers types on the quality of eggs storaged at 20 °C for 6 weeks. Three hundred eggs were coated with rice protein at 8% solution combined with glycerol, propylene glycol or sorbitol. Uncoated eggs showed the highest weight loss (5.31%), while rice protein with glycerol (4.29%) propylene glycol (4.13%) and sorbitol (4.07%) solutions were effective in preventing weight lost. Uncoated eggs had the worst HU (58.40), albumen (9.52) and yolk (7.06) pH, and YI (0.33) after 6 weeks of storage. The eggs coated of rice protein with glycerol, propylene glycol and sorbitol presented results with similar intern quality between them during all the storage period. However, the use of sorbitol as a plasticizer in the coating is more efficient in maintaining control of the increase in albumen pH. Scanning electron microscopy demonstrated a lower surface porosity in coated eggshell, indicating that the use of the coating may provide a protective barrier against the transfer of gases and moisture. In conclusion, the best egg protection results in terms of egg quality are obtained in eggs coated with rice protein and sorbitol.

10.
Basic Res Cardiol ; 113(4): 27, 2018 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29881975

RESUMO

Understanding molecular mechanisms involved in atrial tissue remodeling and arrhythmogenesis in atrial fibrillation (AF) is essential for developing specific therapeutic approaches. Two-pore-domain potassium (K2P) channels modulate cellular excitability, and TASK-1 (K2P3.1) currents were recently shown to alter atrial action potential duration in AF and heart failure (HF). Finding animal models of AF that closely resemble pathophysiological alterations in human is a challenging task. This study aimed to analyze murine cardiac expression patterns of K2P channels and to assess modulation of K2P channel expression in murine models of AF and HF. Expression of cardiac K2P channels was quantified by real-time qPCR and immunoblot in mouse models of AF [cAMP-response element modulator (CREM)-IbΔC-X transgenic animals] or HF (cardiac dysfunction induced by transverse aortic constriction, TAC). Cloned murine, human, and porcine TASK-1 channels were heterologously expressed in Xenopus laevis oocytes. Two-electrode voltage clamp experiments were used for functional characterization. In murine models, among members of the K2P channel family, TASK-1 expression displayed highest levels in both atrial and ventricular tissue samples. Furthermore, K2P2.1, K2P5.1, and K2P6.1 showed significant expression levels. In CREM-transgenic mice, atrial expression of TASK-1 was significantly reduced in comparison with wild-type animals. In a murine model of TAC-induced pressure overload, ventricular TASK-1 expression remained unchanged, while atrial TASK-1 levels were significantly downregulated. When heterologously expressed in Xenopus oocytes, currents of murine, porcine, and human TASK-1 displayed similar characteristics. TASK-1 channels display robust cardiac expression in mice. Murine, porcine, and human TASK-1 channels share functional similarities. Dysregulation of atrial TASK-1 expression in murine AF and HF models suggests a mechanistic contribution to arrhythmogenesis.


Assuntos
Fibrilação Atrial/metabolismo , Remodelamento Atrial , Átrios do Coração/metabolismo , Insuficiência Cardíaca/metabolismo , Ventrículos do Coração/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Remodelação Ventricular , Potenciais de Ação , Animais , Fibrilação Atrial/genética , Fibrilação Atrial/patologia , Fibrilação Atrial/fisiopatologia , Clonagem Molecular , Modelos Animais de Doenças , Feminino , Átrios do Coração/patologia , Átrios do Coração/fisiopatologia , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Frequência Cardíaca , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas do Tecido Nervoso/genética , Oócitos , Canais de Potássio de Domínios Poros em Tandem/genética , Transdução de Sinais , Sus scrofa , Remodelação Ventricular/efeitos dos fármacos , Xenopus laevis
11.
J Exp Biol ; 221(Pt 8)2018 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-29530973

RESUMO

Tegu lizards (Salvator merianae) aestivate for up to 5 months during Brazil's winter, when they retreat to burrows and halt most activities. Dormant tegus reduce their gastrointestinal (GI) mass, which allows a substantial energy economy. This strategy, however, implies that the first post-dormancy digestion would be more costly than subsequent feeding episodes as a result of GI atrophy. To address this, we determined the postprandial metabolic response (SDA) of the first (M1), second (M2) and several (RM) feeding episodes after tegus' dormancy. Another group of tegus (PF) was subjected to an extra 50 day fasting period after arousal. Glucose, triglycerides and uric acid levels were checked before and after feeding. M1 digestion lasted twice as long and cost twofold more when compared with M2 or RM, in agreement with the idea that GI atrophy inflates digestion cost at the first post-dormancy meal. The SDA response was similar in M2 and RM, suggesting that the GI tract was fully reorganized after the first feeding. The SDA cost was equal in PF and RM, implying that the change in state per se (dormant to arousal) triggers the regrowth of GI, independently of feeding. Fasting tegus at M1 presented higher triglyceride and lower uric acid levels than fed tegus, indicating that fasting is mainly sustained by fat storage. Our results show that seasonal fasting imposes an extra digestion cost to tegus following their next feeding, which is fully paid during their first digestion. This surplus cost, however, is negligible compared with the overall energetic savings from GI tract atrophy during the dormancy period.


Assuntos
Jejum/fisiologia , Lagartos/metabolismo , Lagartos/fisiologia , Animais , Glicemia , Digestão/fisiologia , Trato Gastrointestinal/crescimento & desenvolvimento , Trato Gastrointestinal/fisiologia , Hibernação/fisiologia , Período Pós-Prandial/fisiologia , Estações do Ano , Triglicerídeos/sangue , Ácido Úrico/sangue
12.
J Interv Cardiol ; 31(6): 885-890, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30397939

RESUMO

BACKGROUND: To date, there are no guidelines recommending a specific prophylactic antibiotic treatment in transcatheter aortic valve replacement (TAVR). The aim of this study is to evaluate clinical data after TAVR with different periprocedural antibiotic regimens. METHODS: In May 2015 the institutional rules for periprocedural antibiotic prophylaxis were changed from 3 days to 1 day. Thus, a total of 450 consecutive TAVR patients between February 2014 and June 2016 were classified into two intention-to-treat groups: patients receiving a 1-day Cefuroxime prophylaxis (N = 225); patients receiving a 3-day Cefuroxime prophylaxis (N = 225). RESULTS: One-day Cefuroxime regimen was not associated with shorter hospitalization (3-day Cefuroxime 9 ± 4.7 vs 1-day Cefuroxime 8.9 ± 4.0; P = 0.87). Incidence of diarrhea (26.2% vs 18.2%; P = 0.04) and Clostridium difficile infections (4% vs 0.4%; P = 0.01) were significantly higher in the 3-day group. No endocarditis was registered after 1 year follow-up. There was no difference in 30-day overall mortality rate, major vascular complications, bleeding complications, pacemaker-implantation rate, paravalvular regurgitation, or acute kidney injury between patients groups. CONCLUSION: Three-day Cefuroxime prophylaxis does not seem to be advantageous compared to a shorter 1-day regimen, but even shows a significantly higher incidence of diarrhea and Clostridium difficile infection.


Assuntos
Antibacterianos/administração & dosagem , Antibioticoprofilaxia/métodos , Cefuroxima/administração & dosagem , Substituição da Valva Aórtica Transcateter/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/efeitos adversos , Antibioticoprofilaxia/efeitos adversos , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Cefuroxima/efeitos adversos , Feminino , Mortalidade Hospitalar , Humanos , Análise de Intenção de Tratamento , Tempo de Internação/estatística & dados numéricos , Masculino , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
13.
BMC Pulm Med ; 18(1): 106, 2018 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-29940945

RESUMO

BACKGROUND: Pulmonary arterial hypertension is a rare, progressive disease with poor prognosis. However, there is limited information available on the characteristics of PAH patients outside of North America and Europe. This is particularly important as researchers have described that there are potential geographical and regional differences which are vital to consider in the design of clinical trials as well as PAH treatment. The aim of this study was to describe the epidemiology of PAH (PH group 1) in Latin America. METHODS: A search of electronic databases for studies published in English, Spanish or Portuguese was conducted specifying publication dates from the 1st of January 1987 until 10th October 2016. Two authors independently assessed papers for inclusion and extracted data. A narrative synthesis of the findings was conducted. RESULTS: The search revealed 22 conference abstracts and articles, and on application of the inclusion criteria, six conference abstracts and articles were included in the final review. Studies/registries were based in Argentina, Brazil and Chile. In contrast to the available literature from developed countries, in Latin America, most patients were diagnosed at younger age; nevertheless, the higher prevalence of idiopathic PAH (IPAH) and the advanced stage of the disease at diagnosis were comparable to the existing literature, as the long term survival, despite the lower availability of targeted therapies. CONCLUSION: This study highlights the regional characteristics in the epidemiology of group 1 PH. The recognition of these differences should be considered when developing clinical guidelines and extrapolating diagnostic and treatment algorithms. Equitable access to health care and therapies are also issues that need to be addressed in Latin America. Information coming from a large prospective registry representing the different populations in Latin America is of critical importance to increase disease awareness in the region and improve diagnosis and management.


Assuntos
Hipertensão Pulmonar/epidemiologia , Humanos , América Latina/epidemiologia , Prevalência , Prognóstico
14.
Plant Physiol ; 170(3): 1732-44, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26739234

RESUMO

Our knowledge of the factors mediating ethylene-dependent ripening of climacteric fruit remains limited. The transcription of ethylene-regulated genes is mediated by ethylene response factors (ERFs), but mutants providing information on the specific role of the ERFs in fruit ripening are still lacking, likely due to functional redundancy among this large multigene family of transcription factors. We present here a comprehensive expression profiling of tomato (Solanum lycopersicum) ERFs in wild-type and tomato ripening-impaired tomato mutants (Never-ripe [Nr], ripening-inhibitor [rin], and non-ripening [nor]), indicating that out of the 77 ERFs present in the tomato genome, 27 show enhanced expression at the onset of ripening while 28 display a ripening-associated decrease in expression, suggesting that different ERFs may have contrasting roles in fruit ripening. Among the 19 ERFs exhibiting the most consistent up-regulation during ripening, the expression of 11 ERFs is strongly down-regulated in rin, nor, and Nr tomato ripening mutants, while only three are consistently up-regulated. Members of subclass E, SlERF.E1, SlERF.E2, and SlERF.E4, show dramatic down-regulation in the ripening mutants, suggesting that their expression might be instrumental in fruit ripening. This study illustrates the high complexity of the regulatory network connecting RIN and ERFs and identifies subclass E members as the most active ERFs in ethylene- and RIN/NOR-dependent ripening.


Assuntos
Etilenos/farmacologia , Frutas/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Elementos de Resposta/genética , Solanum lycopersicum/genética , Análise por Conglomerados , Frutas/fisiologia , Redes Reguladoras de Genes , Genes de Plantas/genética , Genes Reguladores/genética , Solanum lycopersicum/fisiologia , Mutação , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
J Interv Cardiol ; 30(1): 72-78, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27882613

RESUMO

OBJECTIVES: In this study, we compare procedural results of our first Evolut R (Medtronic, Minneapolis, MN, USA) implantations with the last CoreValve implantations. Main endpoints include paravalvular regurgitation, major vascular complications, stroke, and pacemaker implantation. BACKGROUND: The evolution of transcatheter aortic valve replacement (TAVR) was possible due to various technical improvements, leading to better periprocedural and long-term outcome. The newly designed Evolut R valve has the potential to further improve TAVR's performance. METHODS: We retrospectively analyzed our first 100 consecutive patients who received the Evolut R valve with the last 100 consecutive patients who received the CoreValve prosthesis between July 2013 and February 2016. Only patients treated with a 26 mm or 29 mm bioprosthesis were included. RESULTS: No significant differences in patient characteristics were noticed. Both angiography and echocardiography after TAVR showed significantly higher rates of "none or trace" regurgitation in the Evolut R group (angiography: 67% Evolut R vs. 29.3% CoreValve; P < 0.001; echocardiography: 68% Evolut R vs. 46.5% CoreValve; P < 0.05). No significant differences were seen in 30-day mortality (7% CoreValve vs. 1% Evolut R), stroke rates (3% CoreValve vs. 2% Evolut R), pacemaker implantation rates (24% CoreValve vs. 23% Evolut R), and major vascular complications (6% CoreValve vs. 1% Evolut R). Implantations were significantly higher with the Evolut R prosthesis. CONCLUSIONS: TAVR with the new Evolut R resulted in significantly lower paravalvular regurgitation. This may be due to redesigned cell geometry and higher precision during implantations, as well as the ability to resheath a malpositioned valve.


Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica , Bioprótese , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Idoso , Idoso de 80 Anos ou mais , Insuficiência da Valva Aórtica/etiologia , Estenose da Valva Aórtica/diagnóstico por imagem , Ecocardiografia , Feminino , Humanos , Masculino , Desenho de Prótese , Estudos Retrospectivos , Resultado do Tratamento
16.
Toxicol Ind Health ; 33(2): 147-158, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26655915

RESUMO

Titanium dioxide nanoparticles (TiO2 NP) are present in several daily use products, and the risks associated with their bioaccumulation must be stablished. Thus, an evaluation of several toxicological-related effects was conducted after intraperitoneal injection of TiO2 NPs in mice. Mice were divided into two groups, which received 2 mg kg-1 day-1 of TiO2 NPs or vehicle saline. Assessments of body and organ weight as well as biochemical, hematological, and histopathological analyses were performed in order to evaluate adverse effects. The results showed that treatment resulted in an increased visceral and abdominal fat deposition, as well as a mononuclear inflammatory infiltrates in the abdominal fat tissue. The TiO2 NPs induced significant decrease in the weight gain and splenomegaly. Additionally, TiO2 NP-treated mice showed altered hematological parameters and significant liver injuries, which were characterized by histopathological and biochemical changes. Our results also indicated that TiO2 NPs were absorbed and significantly accumulated in the spleen, liver, and kidney. These results showed the ability of TiO2 NPs to infiltrate different organs and to induce inflammation and liver and spleen damage with visceral fat accumulation. The data obtained are useful for the governmental authorities to legislate and implement regulations concerning the use and the production of this kind of material that might be hazardous to the living beings, as well as to the environment.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Inflamação/induzido quimicamente , Gordura Intra-Abdominal/efeitos dos fármacos , Nanopartículas Metálicas/efeitos adversos , Titânio/efeitos adversos , Animais , Injeções Intraperitoneais , Masculino , Camundongos , Titânio/administração & dosagem
17.
Nitric Oxide ; 61: 10-19, 2016 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-27693703

RESUMO

Nitric oxide (NO) is a signaling molecule involved in plant response to various abiotic stresses. However, the application of NO donors in agriculture is hampered by the instability of these compounds. Despite the successful uses of NO-releasing nanoparticles for biomedical purposes and the variety of nanomaterials developed as carrier systems of agrochemicals, the potential applications of nanocarriers for NO delivery in plants have not yet been tested. Herein, we report the synthesis and characterization of chitosan nanoparticles (CS NPs) containing the NO donor S-nitroso-mercaptosuccinic acid (S-nitroso-MSA). The efficiency of these NO-releasing NPs in mitigating the deleterious effects of salinity on maize plants was compared to that of the non-encapsulated NO donor. The NPs were synthesized through ionotropic gelation process, and mercaptosuccinic acid (MSA), the NO donor precursor, was encapsulated into CS NPs (91.07% encapsulation efficiency). Free thiol groups of MSA-CS NPs were nitrosated, leading to S-nitroso-MSA-CS NPs (NO-releasing NPs). The incorporation of S-nitroso-MSA into CS NPs allowed a sustained NO release. Treatments of salt-stressed maize plants with S-nitroso-MSA-CS NPs resulted in a higher leaf S-nitrosothiols content compared to that of free S-nitroso-MSA. Moreover, S-nitroso-MSA-CS NPs were more efficient than was the free NO donor in the amelioration of the deleterious effects of salinity in photosystem II activity, chlorophyll content and growth of maize plants because the protective action of the nanoencapsulated S-nitroso-MSA was achieved at lower dosages. Overall, these results demonstrate the positive impact of S-nitroso-MSA nanoencapsulation in increasing NO bioactivity in maize plants under salt stress.


Assuntos
Quitosana/química , Nanopartículas/química , Óxido Nítrico/química , Tolerância ao Sal/efeitos dos fármacos , Cloreto de Sódio/efeitos adversos , Zea mays/efeitos dos fármacos , Biotecnologia , Nanotecnologia , Óxido Nítrico/farmacocinética , Óxido Nítrico/farmacologia , Tiomalatos/química
18.
Anal Chem ; 86(19): 9391-3, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-25162751

RESUMO

Although the effect of magnetic field (B) on electrochemical reactions (magnetoelectrolysis phenomenon) has been long known, it has not been considered in electrochemical reactions analyzed in situ by magnetic resonance methods, such as nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and magnetic resonance imaging (MRI), which are intrinsically performed in the presence of B. In this report, the effect of B on the copper electrodeposition reaction, measured by a low-field (0.23 T) NMR spectrometer, was demonstrated. As expected, an enhancement in the reaction rate in comparison to the ex situ electrodeposition reaction was observed. Such enhancement was not dependent on electrodes/magnetic field orientations. Parallel and perpendicular orientations showed similar electrodeposition rates, which is explained by the cyclotron flows generated by distortions in electric and magnetic field lines near the electrode and the electrode edge. Therefore, NMR spectroscopy is not a passive analytical method, as assumed in preceding in situ spectroelectrochemical studies. Although the magnetoelectrolysis phenomenon demonstrated in this report used a paramagnetic ion, it can also be observed for diamagnetic species, since the magnetoelectrolysis phenomenon is independent of the nature of the species. Consequently, similar convection effects may occur in other electrochemical nuclear magnetic resonance (EC-NMR) experiments, such as the electrochemical reaction of organic molecules, as well as in electrocatalysis/fuel cells, lithium-ion batteries, and experiments that use electrochemical electron paramagnetic resonance (EC-EPR) and electrochemical magnetic resonance imaging (EC-MRI).

19.
Brain ; 136(Pt 12): 3738-52, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24136825

RESUMO

Alzheimer's disease is the commonest cause of dementia in the elderly, but its pathological determinants are still debated. Amyloid-ß plaques and neurofibrillary tangles have been implicated either directly as disruptors of neural function, or indirectly by precipitating neuronal death and thus causing a reduction in neuronal number. Alternatively, the initial cognitive decline has been attributed to subtle intracellular events caused by amyloid-ß oligomers, resulting in dementia after massive synaptic dysfunction followed by neuronal degeneration and death. To investigate whether Alzheimer's disease is associated with changes in the absolute cell numbers of ageing brains, we used the isotropic fractionator, a novel technique designed to determine the absolute cellular composition of brain regions. We investigated whether plaques and tangles are associated with neuronal loss, or whether it is dementia that relates to changes of absolute cell composition, by comparing cell numbers in brains of patients severely demented with those of asymptomatic individuals-both groups histopathologically diagnosed as Alzheimer's-and normal subjects with no pathological signs of the disease. We found a great reduction of neuronal numbers in the hippocampus and cerebral cortex of demented patients with Alzheimer's disease, but not in asymptomatic subjects with Alzheimer's disease. We concluded that neuronal loss is associated with dementia and not the presence of plaques and tangles, which may explain why subjects with histopathological features of Alzheimer's disease can be asymptomatic; and exclude amyloid-ß deposits as causes for the reduction of neuronal numbers in the brain. We found an increase of non-neuronal cell numbers in the cerebral cortex and subcortical white matter of demented patients with Alzheimer's disease when compared with asymptomatic subjects with Alzheimer's disease and control subjects, suggesting a reactive glial cell response in the former that may be related to the symptoms they present.


Assuntos
Doença de Alzheimer/patologia , Encéfalo/patologia , Neurônios/patologia , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Contagem de Células , Feminino , Humanos , Indóis , Masculino , Emaranhados Neurofibrilares/patologia , Fosfopiruvato Hidratase/metabolismo , Placa Amiloide/patologia
20.
Issues Ment Health Nurs ; 35(5): 356-63, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24766170

RESUMO

The study aimed to analyze the clinical aspects of the treatment of crack cocaine and excessive alcohol users who were seen in a Psychosocial Care Center of Alcohol and Other Drugs (CAPS AD) in Sobral, Ceará, during the years 2010 and 2011. This is an exploratory descriptive and documentary study, with a retrospective quantitative approach. The sample was composed of 567 medical records of drug users, from which 291 were crack cocaine users, and 276 were alcohol users. For data collection, a form was developed based on the Care Script Service, the data from which was then used to populate a database in an EPI INFO 7, a statistics software system. In both groups of users, males were predominant (85%, n = 482), and were between the ages of 20 and 29 years for crack users (50.9%, n = 148), and between 30 and 39 years for alcohol users (31.9%, n = 88). There were significant differences between crack cocaine users and alcohol users in liver disorders (p < 0.01) and withdrawal syndrome (p < 0.05), however, there were similar signs and symptoms between users. Crack users hospitalized less frequently (OR 0.33 [95% CI 0.23 to 0.47 p < 0.01]). Suicidal ideation and suicide attempts were similar in both crack cocaine and alcohol users. Thus, this research will lead to new proposals for health care professionals in order to enhance and improve the care provided to service customers in CAPS AD.


Assuntos
Alcoolismo/enfermagem , Alcoolismo/psicologia , Transtornos Relacionados ao Uso de Cocaína/enfermagem , Transtornos Relacionados ao Uso de Cocaína/psicologia , Centros de Tratamento de Abuso de Substâncias , Adulto , Brasil , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
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