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1.
Anal Bioanal Chem ; 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32025768

RESUMO

This manuscript describes the development of the restricted access carbon nanotube (RACNT) as a selective stationary phase for microextraction by packed sorbent (MEPS) to determine antipsychotics (chlorpromazine, clozapine, olanzapine, and quetiapine) in untreated plasma samples from schizophrenic patients by ultra-high liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The synthesis was achieved by chemically covering commercial multi-walled carbon nanotubes with bovine serum albumin (BSA) to subsequently pack the material in a polyethylene conical tube (1000 µL). The RACNTs' sorbents were able to exclude about 97% of the plasma proteins, maintaining the same performance for about 100 assays. The MEPS variables (sample pH, draw-eject cycles, desorption and phase cleanup) were evaluated to improve sensibility and selectivity. The MEPS/UHPLC-MS/MS method was linear at concentrations ranging from the lower limit of quantification (10.0 ng mL-1) to the upper limit of quantification (200-700 ng mL-1) with coefficients of determinations higher than 0.99. The precision assays presented relative standard deviation (RSD) values lower than 13%, and the accuracy assays presented relative error (RE) values that ranged from - 8.01 to 11.53%. Neither significant matrix effects nor carryover was observed. The developed method was successfully applied to determine antipsychotics drugs for therapeutic drug monitoring of schizophrenic patients.

2.
Anal Chim Acta ; 1102: 11-23, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32043990

RESUMO

Magnetic restricted-access carbon nanotubes (M-RACNTs) were synthesised and used for dispersive solid phase extraction of organophosphates (chlorpyriphos, malathion, disulfoton, pirimiphos) from commercial bovine raw milk samples. Due to their magnetic susceptibility, M-RACNTs were easily separated from the samples/solvents using a neodymium magnet, and the extracted organophosphates were analysed by gas chromatography-mass spectrometry. The protein exclusion capacity was about 100%. Kinetic and isotherm data (for M-RACNTs - malathion interaction) were adequately adjusted to the pseudo-second order and Sips models, respectively, and the maximum adsorption capacity was about 0.55 mg g-1. The method presented linear ranges from 5.0 to 40.0 µg L-1 for all analytes, with determination coefficients from 0.9902 to 0.9963. The intra-assay precisions (as relative standard deviation) and accuracies (as relative error) ranged from 10.47 to 19.85% and from -0.18 to -18.80%, respectively, whereas the inter-assay precisions ranged from 6.48 to 18.76% and from -0.22 to 19.49%, respectively for 5.0, 20.0 and 40.0 µg L-1 organophosphates levels. The organophosphates were not stable at 4 and 24 h (relative errors ranged from -39.30 to 72.07% and -69.64 to 75.95%, respectively). Limits of detection ranged from 0.36 to 0.95 µg L-1, and 5 µg L-1 was defined as the limit of quantification for all the analytes. The proposed method was applied in the determination of organophosphates in five commercial milk samples, and no pesticides were detected.

3.
Arq Bras Cir Dig ; 32(3): e1456, 2019.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31826083

RESUMO

BACKGROUND: Diversion colitis is still very common in our country, since the stoma creation is a common practice especially in situations of trauma. needing treatment for this condition. AIM: To evaluate the therapeutic effect of rectal infusion of Curcuma longa (turmeric) in the excluded intestinal segment of rats. METHOD: Eighteen Wistar rats were used and submitted to colostomy: control group (n=8) under rectal saline infusion and group CL, receiving intra-rectal infusion of Curcuma longa extract (n=10). After 21 days of treatment they were submitted to euthanasia; the intestinal segment excluded from intestinal transit was resected and sent to histopathological evaluation, classifying the degree of inflammation and of vascular congestion. RESULTS: The average of inflammation was 2.7 in the control group vs. 2.6 in the CL group (p=0.3125), while the mean vascular congestion was 2.3 and 2.1, respectively, in the control and CL groups (p=0.1642). CONCLUSION: Intra-rectal infusion of Curcuma longa extract was not able to minimize the inflammatory process or vascular congestion in the diversion colitis of rats subjected to colostomy.

4.
Lasers Med Sci ; 2019 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-31811497

RESUMO

The aim of the study was to compare the effect of Ibuprofen and the application of photobiomodulation therapy protocol on the reduction of postoperative pain in endodontically treated teeth using a randomized clinical trial design. Seventy patients, diagnosed with symptomatic irreversible pulpitis, were selected. Treatment was performed by a single operator; a reciprocal system was used to prepare the canals; they were obturated using the Tagger's hybrid technique and coronally sealed with glass-ionomer cement. After treatment, patients were randomly divided into 2 groups. In the active control group, two Ibuprofen 600 mg tablets were administered within a 12-h interval. In the photobiomodulation therapy group, the irradiation was applied after treatment. The evaluation of postoperative pain was performed by another researcher blinded to the groups at 6, 12, 24, and 72 h intervals after treatment. To measure the outcome, two pain scales were used: numerical rate scale (NRS) and verbal rate scale (VRS). Data were analyzed using the chi-square, Mann-Whitney, and Wilcoxon paired tests. Outcome was superior with photobiomodulation therapy at 6 h (p < 0.001), 12 h (p = 0.005), and 24 h (p < 0.001) intervals compared with Ibuprofen. The results for the 72 h (p = 0.317) interval were similar, both in the VRS and NRS scales. It may be concluded that the use of photobiomodulation therapy was effective in reducing pain within the first 24 h when compared with the administration of Ibuprofen 600 mg.

5.
Arq Bras Cardiol ; 113(4): 787-891, 2019 Nov 04.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31691761
6.
Arq Bras Cardiol ; 113(3): 374-380, 2019.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31482989

RESUMO

BACKGROUND: Stress is a state of threat to the balance of the organism, which can cause biological and psychological changes. In hypertensive patients, stress can interfere with blood pressure levels, influence on food choices and neglect of the diet. OBJECTIVE: This study aims to describe the relationship between stress and dietary intake of hypertensive patients. METHODS: A transversal study was carried out at the Arterial Hypertension Clinic of the Cardiology Institute of Rio Grande do Sul, Brazil. The participants were aged ≥ 18 years and hypertensive. Blood pressure, food consumption and anthropometric measurements were collected. The variables related to stress were evaluated by the Lipp's Stress Symptoms Inventory (LSSI) for adults. Significance level of 5% has been considered for all analyzed data. RESULTS: The number of participants was 100. There was a higher prevalence of the female sex (67%), the mean age of the study population was 55.87 ± 12.55 years. Among the participants, 86% were classified in some of the stress phases, on which 57% were in the resistance phase. It was observed that there was no correlation between the presence of stress (as well as their actions), pressure levels and food consumption. The consumption of foods rich in lipids and individuals with a prevalence of psychological symptoms of stress displayed a significant association. CONCLUSIONS: Rich in fat dietary has been the first choice in patients with psychological symptoms of stress. Further studies regarding remodeled dietary intake and blood pressure levels in relation to the stress phases are suggested. These findings are important to contribute to the development of prevention and treatment strategies for cardiovascular diseases.

7.
Arq. bras. cardiol ; 113(3): 374-380, Sept. 2019. tab, graf
Artigo em Inglês | LILACS-Express | ID: biblio-1038553

RESUMO

Abstract Background: Stress is a state of threat to the balance of the organism, which can cause biological and psychological changes. In hypertensive patients, stress can interfere with blood pressure levels, influence on food choices and neglect of the diet. Objective: This study aims to describe the relationship between stress and dietary intake of hypertensive patients. Methods: A transversal study was carried out at the Arterial Hypertension Clinic of the Cardiology Institute of Rio Grande do Sul, Brazil. The participants were aged ≥ 18 years and hypertensive. Blood pressure, food consumption and anthropometric measurements were collected. The variables related to stress were evaluated by the Lipp's Stress Symptoms Inventory (LSSI) for adults. Significance level of 5% has been considered for all analyzed data. Results: The number of participants was 100. There was a higher prevalence of the female sex (67%), the mean age of the study population was 55.87 ± 12.55 years. Among the participants, 86% were classified in some of the stress phases, on which 57% were in the resistance phase. It was observed that there was no correlation between the presence of stress (as well as their actions), pressure levels and food consumption. The consumption of foods rich in lipids and individuals with a prevalence of psychological symptoms of stress displayed a significant association. Conclusions: Rich in fat dietary has been the first choice in patients with psychological symptoms of stress. Further studies regarding remodeled dietary intake and blood pressure levels in relation to the stress phases are suggested. These findings are important to contribute to the development of prevention and treatment strategies for cardiovascular diseases.


Resumo Fundamento: O estresse é um estado de ameaça ao equilíbrio do organismo, podendo causar alterações biológicas e psicológicas. No paciente hipertenso o estresse pode interferir nos níveis pressóricos e gerar influência nas escolhas alimentares e negligência da dieta. Objetivo: Este estudo tem como objetivo descrever a relação entre o estresse e consumo alimentar de pacientes hipertensos. Métodos: Estudo transversal, desenvolvido no Ambulatório de Hipertensão Arterial do Instituto de Cardiologia do Rio Grande do Sul. Participaram da pesquisa indivíduos hipertensos com idade > 18 anos. Foram coletados dados de pressão arterial, consumo alimentar e medidas antropométricas. As variáveis relacionadas ao estresse foram avaliadas pelo inventário de sintomas de stress para adultos de Lipp (ISSL). Em todas as análises foi considerando um nível de significância 5% (p < 0,05). Resultados: O número de participantes foi de 100. Houve maior prevalência no sexo feminino (67%), a idade média da população estudada foi 55,87 ± 12,55 anos. Dos participantes, 86% se classificaram em alguma das fases do estresse, sendo que destes, 57% estavam na fase de resistência. Observou-se que não houve correlação entre a presença de estresse (bem como suas fases), níveis pressóricos e consumo alimentar. O consumo de alimentos ricos em lipídios em hipertensos com sintomas de estresse apresentou significância estatística. Conclusão: Os alimentos ricos em gordura prevaleceram entre as escolhas alimentares nos pacientes com sintomas psicológicos de estresse. Sugere-se mais estudos em relação a alteração do consumo alimentar e níveis pressóricos em relação às fases do estresse.

8.
Mikrochim Acta ; 186(9): 647, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31456048

RESUMO

Restricted-access nanoparticles (RANPs) were prepared from bovine serum albumin by coacervation. They have an average sized of 311 nm. They were characterized and used to capture the ß-blockers atenolol, metoprolol and propranolol from untreated biological samples. It is shown that both high protein affinity drugs (propranolol) and low protein affinity drugs (atenolol) could be rapidly extracted from plasma. This is revealed by kinetic and isothermal adsorption studies. On the other hand, almost all proteins from the sample were excluded. This demonstrates the efficiency of RANPs as restricted-access material. Sample preparation was carried out by solid phase microextraction using a probe obtained by the fixation of the RANPs at the end of a glass capillary. Atenolol (in concentrations from 100 to 1200 µg L-1), metoprolol (from 80 to 1000 µg L-1) and propranolol (from 15 to 200 µg L-1) were extracted from spiked plasma samples and analyzed by LC MS/MS without using a separation column. Correlation coefficients >0.99, good precision, accuracy, robustness, and lack of memory effects were observed for all of the analytes. The detection limits (at an S/N of 3) are 25.6, 14.6, and 3.8 µg L-1 for atenolol, metoprolol and propranolol, respectively. Ten samples can be simultaneously extracted within ∼15 min. Plasma samples of patients undergoing medical treatment were successfully analyzed with the method. Graphical abstract Schematic representation of a bovine serum albumin-based restricted access nanoparticle that exclude proteins from a human plasma sample but capture the small analytes.

9.
Arq Bras Cardiol ; 113(5): 970-975, 2019 Nov.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31432980

RESUMO

BACKGROUND: The diagnosis of arterial hypertension based on measurements of blood pressure in the office has low accuracy. OBJECTIVE: To evaluate the prevalence of masked hypertension (MH) and white-coat hypertension through home blood pressure monitoring (HBPM) in pre-hypertensive and stage 1 hypertensive patients. METHOD: Retrospective study, of which sample consisted of individuals with BP ≥ 120/80 mmHg and < 160/100 mmHg at the medical office without the use of antihypertensive medication and who underwent exams on the HBPM platform by telemedicine (TeleMRPA) between May 2017 and September 2018. The four-day MRPA protocol was used, with 24 measurements, using automated, validated, calibrated equipment with a memory function. RESULTS: The sample consisted of 1,273 participants, of which 739 (58.1%) were women. The mean age was 52.4 ± 14.9 years, mean body mass index (BMI) 28.4 ± 5.1 kg/m2. The casual BP was higher than the HBPM in 7.6 mmHg for systolic blood pressure (SBP) and 5.2 mmHg for diastolic blood pressure (DBP), both with statistical significance (p < 0.001). There were 558 (43.8%) normotensive individuals; 291 (22.9%) with sustained hypertension; 145 (11.4%) with MH and 279 (21.9%) with white-coat hypertension (WCH), with a diagnostic error by casual BP in the total sample in 424 (33.3%) patients. In stage 1 hypertensive individuals, the prevalence of WCH was 48.9%; in prehypertensive patients, the prevalence of MH was 20.6%. CONCLUSION: MH and WCH have a high prevalence rate in the adult population; however, in prehypertensive or stage 1 hypertensive patients, the prevalence is higher. Out-of-office BP measurements in these subgroups should be performed whenever possible to prevent misdiagnosis.

10.
Analyst ; 144(14): 4320-4330, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31192335

RESUMO

Restricted access molecularly imprinted polymers (RAMIPs) are hybrid materials that present selective binding sites for a template (or similar molecules), and an external hydrophilic layer that avoids the binding of proteins to the material, making them appropriate for the sample preparation of protein fluids. RAMIPs have been used successfully in online and offline solid phase extractions, but there is no application as a fiber in solid phase microextraction (SPME), to the best of our knowledge. In this paper, molecularly imprinted fibers were synthesized inside glass capillary tubes (0.53 mm i.d.), using diazepam and methacrylic acid as template and functional monomer, respectively. The MIP fibers were coated with a cross-linked bovine serum albumin (BSA) layer, resulting in RAMIP fibers that were used in the SPME of benzodiazepines directly from biological fluids. The BSA layer acts as a protective barrier that avoids the binding of proteins from the sample by an electrostatic repulsion mechanism. The protein exclusion capacity of the RAMIP fiber was about 98%, which is selective to benzodiazepines in comparison with other drugs (citalopram and fluoxetine). The SPME was optimized and the extraction conditions were set as follows: 1000 µL of the sample diluted with water (1 : 0.5, v : v), no pH adjustment, an extraction time of 20 min at 500 rpm, and elution with 200 µL of acetonitrile for 5 min at 500 rpm. The fibers were used in the SPME of benzodiazepines directly from plasma samples, followed by HPLC-DAD analyses. The method was linear for bromazepam (50-750 µg L-1), clonazepam (15-250 µg L-1), alprazolam (15-350 µg L-1), nordiazepam (100-2100 µg L-1) and diazepam (100-2600 µg L-1), with correlation coefficients higher than 0.97. Relative standard deviations (precision) and relative errors (accuracy) ranged from 0.5 to 20.0%, and -15.6 to 21.6%, respectively.


Assuntos
Benzodiazepinas/sangue , Ácidos Polimetacrílicos/química , Adsorção , Animais , Benzodiazepinas/química , Bovinos , Diazepam/química , Humanos , Cinética , Metacrilatos/química , Impressão Molecular/métodos , Ácidos Polimetacrílicos/síntese química , Estudo de Prova de Conceito , Soroalbumina Bovina/química , Microextração em Fase Sólida/instrumentação , Microextração em Fase Sólida/métodos
11.
Neurourol Urodyn ; 38(5): 1212-1221, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30932250

RESUMO

AIMS: To evaluate the functional and molecular alterations of contractile and relaxant machinery in the bladder and urethra that lead to the underactive bladder (UAB) in old female mice. METHODS: Female young (3-months) and old (18-months) C57BL/6 mice were used. Urodynamic was assessed in awake and anaesthetized mice. Electrical-field stimulation (EFS) and concentration-response curves to contractile and relaxing agents in isolated bladders and urethras were performed. Messenger RNA (mRNA) expressions of muscarinic, adrenergic, and transient receptor potential vanilloid-4 (TRPV4), and of the enzymes tyrosine hydroxylase and neuronal nitric oxide synthase (nNOS) were determined. Bladder cyclic adenosine monophosphate (cAMP) levels were measured. RESULTS: Cystometry in old mice showed incapacity to produce bladder emptying. On filter paper, old mice showed reduced urinary spots. Compared to the young group, bladder contractions induced by EFS and carbachol were lower in old mice. The ß3 -adrenoceptor agonist mirabegron promoted higher bladder relaxation and elevation of cAMP levels in old mice. In old mice urethras, the α1a -adrenoceptor agonist phenylephrine produced higher contractions, but no differences were found for the NO donor sodium nitroprusside-induced relaxations. In old mice, increased mRNA expressions of ß3 - and α1a -adrenoceptors in bladder and urethra were found, respectively, whereas the muscarinic M2 and M3 receptors and ß2 -adrenoceptors did not change between groups. Reduced mRNA expressions of tyrosine hydroxylase and nNOS were found in old mouse urethras. Additionally, TRPV4 expression was reduced in bladder urothelium from old mice. CONCLUSION: Age-associated mouse UAB is the result of autonomic dysfunction at multiple levels leading to the less sensitive and overrelaxed bladder, along with urethral hypercontractility.

12.
J Craniomaxillofac Surg ; 47(7): 1046-1053, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30898481

RESUMO

PURPOSE: This study aimed to assess the effect of surgically assisted rapid maxillary expansion (SARME) associated with pterygomaxillary disjunction (PD) on mandibular positioning. MATERIALS AND METHODS: A two-phase systematic review registered with the PROSPERO database was performed. Search strategies were developed for specific databases (PubMed, Scopus, Web of Science, COCHRANE, LILACS, and DOSS), including the gray literature (Open Gray, Google Scholar, and ProQuest). The methodological and evidential quality of the included studies were assessed. RESULTS: Among 680 studies, four were selected for inclusion. In general, a low risk of bias was observed. The studies included a total of 142 adults, and used imaging to perform linear measurements (preoperatively and postoperatively). The main outcomes were maxillomandibular transverse index (difference between effective mandibular width - distance between the left and right antagonist points - and maxillary width), sagittal (forward and backward) and vertical (impaction and extrusion) changes, dental show, chin projection, and altered mandibular position. CONCLUSION: Although the study demonstrated some mandibular position changes after SARME associated with PD, there is insufficient current evidence to support this result because of the potential study limitations related to the number of investigations chosen for inclusion. Further research is required to validate this finding.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Técnica de Expansão Palatina , Queixo , Humanos , Mandíbula , Maxila
13.
Clin Oral Investig ; 23(7): 2941-2949, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30613870

RESUMO

OBJECTIVE: This study aimed to prospectively observe gustatory and neurosensory alterations following surgical removal of mandibular third molars. MATERIAL AND METHODS: A prospective clinical study was conducted with patients who required mandibular third molar extraction, recruited from the Division of Oral and Maxillofacial Surgery at the Federal University of Ceará (Brazil). Age, sex, and radiographic signs were recorded. The outcome variables were the presence or absence of gustatory and neurosensory alterations. The patients were observed preoperatively and at 7, 30, 90, and 180 days postoperatively by using gustatory and neurosensory tests. RESULTS: The response to sweet (p = 0.509) and sour (p = 0.078) stimulus did not alter significantly over time. The salty threshold significantly increased from the preoperative to 7- and 30-day postoperative periods, returning to baseline values at 90 days postoperatively (p = 0.038). The bitter threshold increased significantly from the preoperative to 7-day postoperative period, returning to baseline values at 30 days after surgery (p < 0.001). Regarding neurosensory evaluation, there was an altered response to stimulus at 7 days postoperatively in specific studied areas, returning to baseline values 30 days after surgery (p < 0.05). CONCLUSION: The present study shows that mandibular third molar removal was associated with slight sensory disturbances related to mechanical, tactile, and gustatory perception. Regarding the recovery period, all patients returned to normal function without intervention, over a period ranging from 30 to 90 days. CLINICAL RELEVANCE: This study highlighted the importance of a sensory evaluation following removal of third molars, notably regarding mechanical perception and gustatory threshold assessment.


Assuntos
Dente Serotino , Distúrbios do Paladar/etiologia , Extração Dentária , Dente Impactado , Traumatismos do Nervo Trigêmeo , Feminino , Humanos , Masculino , Mandíbula , Dente Molar , Dente Serotino/cirurgia , Estudos Prospectivos , Sensação , Dente Impactado/cirurgia
14.
Chem Pharm Bull (Tokyo) ; 67(1): 23-31, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30606948

RESUMO

Metformin is a euglycemic drug for the treatment of type 2 diabetes mellitus. To date, there are 13 dissolution methodologies described in the U.S. Pharmacopoeia (USP) to evaluate the release profile of metformin from extended-release tablets utilizing either a USP apparatus 1 (basket) or 2 (paddle). In the absence of a protocol for a USP apparatus 3 (reciprocating cylinder), the goal of this work was to develop an in vitro dissolution method for metformin extended-release tablets based on an in vivo-in vitro correlation (IVIVC). Following a systematic evaluation, a final dissolution method, M4, was defined. It applied 30 dips per minute (dpm) over a total period of 10 h into a series of solutions that included 2 h in HCl media (pH 1.2), 1 h in an acetate buffer solution (pH 4.5), 1 h in phosphate buffer solution (PBS) (pH 5.8) and 6 h in PBS (pH 6.8). This method showed a significant IVIVC with a calculated R2 > 0.98 (point-to-point correlation, Level A) and it was successfully used as a tool to assist in the development of generic extended release formulations for metformin consisting of a lipophilic matrix system.


Assuntos
Preparações de Ação Retardada , Composição de Medicamentos , Medicamentos Genéricos , Metformina/química , Humanos , Farmacopeias como Assunto , Comprimidos , Estados Unidos
15.
Recurso educacional aberto em Português | CVSP - Brasil | ID: cfc-370358

RESUMO

Dengue, chikungunya e zika. Neste verão, pela primeira vez, os vírus dessas 3 doenças estão circulando no Brasil.Todos transmitidos pelo Aedes Aegypti. Quais são as dificuldades para acabar com esse mosquito? O que pode ser feito a partir de agora para que o próximo verão seja diferente? Convidamos Rodrigo Stabeli, vice-presidente de pesquisa e laboratórios e cientista especializado em medicina tropical da Fiocruz para responder a essas perguntas. Também vamos dar orientações para o uso de repelentes na pele e no ambiente e falar sobre a experiência que impede a transmissão da dengue pelo Aedes Aegypti. E, ainda: uma esperança para os próximos anos: uma vacina contra dengue e zika. Participantes: Márcio Nehab, infectologista pediátrico do IFF/Fiocruz.


Assuntos
Dengue , Vírus Chikungunya , Zika virus , Controle de Mosquitos
16.
Recurso educacional aberto em Português | CVSP - Brasil | ID: cfc-370357

RESUMO

Colesterol alto é uma das principais causas de problemas cardíacos no país. O colesterol elevado não provoca sintomas, então não deixe para se cuidar só depois de alguma complicação. E quem pensa que esta é preocupação somente dos adultos está muito enganado. Cada vez mais crianças também estão sofrendo desse mal. Que alimentos são verdadeiros vilões quando o assunto é colesterol? Você sabe qual a diferença entre colesterol bom e ruim? O que fazer quando os níveis de colesterol estão altos no seu exame de sangue? Precisa tomar remédio? Participantes: Mônica Bittencourt, apresentadora do canal saúde; Aurora Issa, cardiologista do INC - Instituto Nacional de Cardiologia; Eduardo Costa, reporter do canal saúde; Caroline Palles, nutricionista; Carolina Meirelles dos Reis, mãe da Liz Meirelles dos Reis, 5 anos.


Assuntos
Colesterol , Hipercolesterolemia
17.
Environ Sci Pollut Res Int ; 26(28): 28481-28489, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30229486

RESUMO

The aim of this work was to study the adsorption and removal of chromium (VI) ions contained in aqueous solutions using a chitosan-based hydrogel synthesized via chemical crosslinking of radical chitosan, polyacrylic acid, and N,N'-methylenebisacrylamide. Fourier-transform infrared spectroscopy confirmed the hydrogel synthesis and presence of reactive functional groups for the adsorption of chromium (VI) ions. The chromium (VI) adsorption mechanism was evaluated using non-linear Langmuir, Freundlich, Redlich-Peterson, and Sips isotherms, with the best fit found by the non-linear Redlich-Peterson isotherm. The maximum chromium (VI) adsorption capacities of the chitosan-based hydrogel were 73.14 and 93.03 mg metal per g dried hydrogel, according to the non-linear Langmuir and Sips isotherm models, respectively. The best kinetic fit was found with the pseudo-nth order kinetic model. The chromium (VI) removal percentage at pH 4.5 and 100 mg L-1 initial metal concentration was 94.72%. The results obtained in this contribution can be useful for future works involving scale-up of a water and wastewater treatment method from a pilot plant to full-scale plant.


Assuntos
Resinas Acrílicas/química , Quitosana/química , Cromo/análise , Hidrogéis/química , Águas Residuárias/química , Adsorção , Cromo/metabolismo , Cinética , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Purificação da Água/métodos
18.
Rapid Commun Mass Spectrom ; 33(1): 116-124, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30378202

RESUMO

RATIONALE: The chromatographic analysis of topiramate and its degradation products is challenging due to the absence of chromophoric moieties in their structures, the wide polarity range of the compounds and their ionization differences. This work proposes two new mass spectrometry approaches for evaluating these analytes. METHODS: Based on the calculated experimental limit of detection (LOD), a highly sensitive high-performance liquid chromatography (HPLC) paired-ion electrospray ionization mass spectrometry (PIESI-MS) method was developed for the determination of topiramate inorganic degradation products. The influence of different solvent systems on the LODs for topiramate and its main degradation products was determined in both positive/negative ionization modes. In addition, a HPLC method to analyze both organic and inorganic degradation products was proposed by mass spectrometry with positive/negative ion switching electrospray ionization. RESULTS: A sensitive HPLC/PIESI-MS method was achieved for the efficient separation of topiramate inorganic degradation products. Both sulfate and sulfamate were detected in the positive selected ion monitoring (SIM) mode with an increased sensitivity compared with the negative SIM mode. The HPLC/ESI-MS analysis with positive/negative ion switching allowed the simultaneous separation and detection of the major degradation products of topiramate in a 10-min run using a single column and a single detector. CONCLUSIONS: Two new alternative MS approaches for analyzing the main degradation products of topiramate were developed. The proposed methods are considered advantageous over the existing methods and can be applied to quality control studies of topiramate.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Topiramato/análise , Limite de Detecção , Sensibilidade e Especificidade , Solventes/química , Sulfatos/química , Ácidos Sulfônicos/química , Topiramato/química
19.
Environ Sci Pollut Res Int ; 26(28): 28490, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30284707

RESUMO

The original publication of this paper contains an error. The correct 4th heading in Table 1 should be "Non-linear sips isotherm". The original article has been corrected.

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