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1.
J Optom ; 16(4): 252-260, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37019707

RESUMO

PURPOSE: To assess the agreement between the Eye Refract, an instrument to perform subjective automated refraction, and the traditional subjective refraction, as the gold standard, in young hyperopes under noncycloplegic and cycloplegic conditions. METHODS: A cross-section and randomized study was carried out, involving 42 participants (18.2 ± 7.7 years, range 6 to 31 years). Only one eye was chosen for the analysis, randomly. An optometrist conducted the refraction with the Eye Refract, while another different optometrist conducted the traditional subjective refraction. Spherical equivalent (M), cylindrical components (J0 and J45), and corrected distance visual acuity (CDVA) were compared between both refraction methods under noncycloplegic and cycloplegic conditions. A Bland-Altman analysis was performed to assess the agreement (accuracy and precision) between both refraction methods. RESULTS: Without cycloplegia, the Eye Refract showed significantly lower values of hyperopia than the traditional subjective refraction (p < 0.009), the mean difference (accuracy) and its 95% limits of agreement (precision) being -0.31 (+0.85, -1.47) D. Conversely, there were no statistical differences between both refraction methods under cycloplegic conditions (p ≥ 0.05). Regarding J0 and J45, both refraction methods manifested no significant differences between them under noncycloplegic and cycloplegic conditions (p ≥ 0.05). Finally, the Eye Refract significantly improved CDVA (0.04 ± 0.01 logMAR) compared with the traditional subjective refraction without cycloplegia (p = 0.01). CONCLUSIONS: The Eye Refract is presented as a useful instrument to determine the refractive error in young hyperopes, the use of cycloplegia being necessary to obtain accurate and precise spherical refraction.


Assuntos
Hiperopia , Presbiopia , Erros de Refração , Humanos , Midriáticos , Testes Visuais , Refração Ocular , Erros de Refração/diagnóstico
2.
Drug Test Anal ; 15(11-12): 1382-1391, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36772848

RESUMO

The ratio of testosterone (T) to epitestosterone (E) determined in urine samples is the main biomarker used to prove T and precursors abused by athletes. Analytically, the correction of the ratio is required by the World Anti-Doping Agency. This work describes a series of experiments aimed to study when it is appropriate to correct the T/E ratio value, using different mass spectrometric techniques since only reports on GC-MS exist. Analyses using external calibrators, controls, and routine samples were performed by three different techniques GC-MS, GC-MSn , and LC-MSn . A statistical comparison of the T/E was performed after the application of two corrections previously published: Isotopic contribution peak area correction (corr_1) and use of a verified internal deuterated internal standard (TD3/ED3) correction (corr_2) and the ratio based on T and E concentrations. The use of external calibration samples introduces biases that influence not only the T and E concentrations but also the T/E ratio, even when both methods of correction are applied. The correction after applying corr_1 method barely contributed to the accuracy of the T/E calculation. Nevertheless, the application of the corr_2 method increased the accuracy between 5% and 6% when comparing theoretical and experimental T/E values. Finally, the best results were obtained by the ratio calculated directly from the estimated concentrations of T and E. Attention must be paid when the T/E is measured by LC-MSn since different acquisition modes produced significantly different results, even in MS/MS when the same transition is used for T and E.

3.
Clin Drug Investig ; 42(11): 949-964, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36173596

RESUMO

BACKGROUND: Unprotected and fragile elderly people in nursing homes experienced the highest mortality rates during the initial coronavirus disease 2019 (COVID-19) pandemic. OBJECTIVE: Our aim was to study the role of two oral anti-inflammatory drugs, colchicine and prednisone, in elderly patients with COVID-19 in geriatric centers. METHODS: A phase II/III, randomized, controlled, multicenter clinical trial was performed in a geriatric population comparing the efficacy and safety of an oral combination of prednisone (60 mg/day for 3 days) and colchicine (at loading doses of 1-1.5 mg/day for 3 days, followed by 0.5 mg/day for 11 days) with the standard treatment, based on intravenous dexamethasone. Primary endpoints assessed the efficacy in reducing death or the modified endpoint death/therapeutic failure to the study drugs over a 28-day period, while secondary endpoints included safety, laboratory changes, and additional therapies used. RESULTS: Fifty-four patients (35 female/19 male) were enrolled, 25 (46.3%) of whom were allocated to the experimental arm and 29 (53.7%) to the control arm. At day 28, no differences in deaths were observed. The combination of mortality or therapeutic failure occurred in 12 (45.13%) patients receiving dexamethasone and 6 (28.13%) patients receiving colchicine/prednisone, resulting in a reduction of risk difference (RD) of - 17% (p = 0.17), with an average reduction of 39% (risk ratio [RR] 0.61) in patients receiving colchicine/prednisone (p = 0.25). Control patients received higher amounts of additional glucocorticoids (p = 0.0095) over a longer time frame (p = 0.0003). Colchicine/prednisone significantly reduced ferritin levels at day 14, as well as D-dimer and lactate dehydrogenase (LDH) levels at day 28. Adverse events were similar in both groups. CONCLUSIONS: The combination colchicine/prednisone compared with intravenous dexamethasone has shown a remarkable trend to increase disease survival over a 28-day period in elderly patients requiring oxygen therapy in geriatric centers, without safety issues. CLINICAL TRIAL REGISTRY: Clinical Trials Registration Number: NCT04492358.


Assuntos
Tratamento Farmacológico da COVID-19 , Humanos , Masculino , Feminino , Idoso , Prednisona/efeitos adversos , Colchicina/efeitos adversos , SARS-CoV-2 , Dexametasona/uso terapêutico , Resultado do Tratamento
4.
Optom Vis Sci ; 98(6): 597-604, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34081650

RESUMO

SIGNIFICANCE: The performance of the Eye Refract (Luneau Technology, Chartres, France), a new instrument to perform aberrometry-based automated subjective refraction, has been previously evaluated in healthy subjects. However, its clinical implications in other ocular conditions are still unknown. PURPOSE: The purpose of this study was to evaluate the agreement between the Eye Refract and the traditional subjective refraction, as the criterion standard, in keratoconus patients with and without intracorneal ring segments (ICRSs). METHODS: A total of 50 eyes of 50 keratoconus patients were evaluated, dividing the sample into 2 groups: 27 eyes without ICRS (37.78 ± 9.35 years) and 23 eyes with ICRS (39.26 ± 13.62 years). An optometrist conducted the refraction with the Eye Refract, and another different optometrist conducted the traditional subjective refraction on the same day. Spherical equivalent (M), cylindrical vectors (J0 and J45), and corrected distance visual acuity were compared between both methods of refraction. In addition, Bland-Altman analysis was performed to assess the agreement between both methods of refraction. RESULTS: There were no statistically significant differences (P ≥ .05) between the Eye Refract and the traditional subjective refraction for all the variables under study in either group. Without ICRS, the mean difference and 95% limits of agreement (upper, lower) were -0.20 (+1.50, -1.89) D for M, -0.14 (+1.40, -1.68) D for J0, and +0.05 (+1.23, -1.14) D for J45. With ICRS, these values worsened to -0.62 (+3.89, -5.12) D for M, +0.06 (+2.46, -2.34) D for J0, and -0.02 (+2.23, -2.28) D for J45. CONCLUSIONS: The Eye Refract seems to offer similar results compared with the traditional subjective refraction in keratoconus patients not implanted with ICRS. However, some patients could show abnormal measurements, especially those with ICRS, who should be treated with caution in clinical practice.


Assuntos
Ceratocone , Aberrometria , Substância Própria/cirurgia , Topografia da Córnea , Humanos , Ceratocone/diagnóstico , Ceratocone/cirurgia , Próteses e Implantes , Implantação de Prótese , Refração Ocular , Testes Visuais
5.
Surg Obes Relat Dis ; 16(10): 1419-1428, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32694041

RESUMO

BACKGROUND: The main cause of death in obese individuals is cardiovascular disease precipitated by atherosclerosis. Endothelial dysfunction and inflammation are considered early events in the development of the disease. OBJECTIVES: The aim of this study was to identify biomarkers of subclinical atherosclerosis in patients with morbid obesity by comparing clinical, vascular, and biochemical parameters indicative of endothelial dysfunction in patients with and without atheromatous plaque and monitoring changes after bariatric surgery. SETTINGS: Multicenter collaboration between Biochemistry and Biomedicine Department in Barcelona University and University Hospital Arnau de Vilanova in Lleida. METHODS: Plasma samples from 66 patients with morbid obesity were obtained before bariatric surgery and at 6 and 12 months after. Patients were divided into 2 groups based on the presence of atheromatous plaque. We used contrast-enhanced carotid ultrasound, enzyme-linked immunosorbent assay, Griess, and EndoPAT-2000 methods. RESULTS: Patients with plaque showed the worst profile of cardiovascular risk factors. Carotid intima-media thickness and plasminogen activator inhibitor-1 were higher in plaque group (P < .0001). After bariatric surgery, vasa vasorum, oxidized low-density lipoprotein, and plasminogen activator inhibitor-1 decreased (P < .0001 in all cases). CONCLUSIONS: Obesity promotes atherogenesis, leading to vascular endothelial damage. Bariatric surgery reduces cardiovascular risk and the prognosis is better for patients without plaque. The increase in plasminogen activator inhibitor-1, carotid intima-media thickness, and vasa vasorum proliferation might be the first alterations in the atheromatous process in obesity and could serve as good biomarkers of subclinical atherosclerosis.


Assuntos
Aterosclerose , Cirurgia Bariátrica , Obesidade Mórbida , Aterosclerose/etiologia , Biomarcadores , Espessura Intima-Media Carotídea , Humanos , Obesidade Mórbida/cirurgia , Fatores de Risco , Ultrassonografia
6.
Rev Bras Enferm ; 73(5): e20190554, 2020.
Artigo em Português, Inglês | MEDLINE | ID: mdl-32667407

RESUMO

OBJECTIVES: to characterize the homeless families who use a Public Shower Room; identify significant life events/phenomena for the family's transition to homelessness; understand the relationship between significant life events; identify future expectations of respondents. METHODS: an exploratory, descriptive study using the interview and thematic content analysis. Sample consisted of public shower room users. RESULTS: mental illness, social, personal and family factors justify the transition of subjects to homelessness. The total absence of hopelessness alternates with expectations for the future based on resilience and hope. Final Considerations: we highlight in the study the self-determination expressed in small expressions of the narrative, on the one hand, as well as aspects related to the evolution of family relationships, on the other.


Assuntos
Relações Familiares/psicologia , Pessoas Mal Alojadas/psicologia , Adulto , Idoso , Feminino , Pessoas Mal Alojadas/estatística & dados numéricos , Humanos , Entrevistas como Assunto/métodos , Masculino , Pessoa de Meia-Idade , Narração , Pesquisa Qualitativa
7.
J Biomed Mater Res B Appl Biomater ; 108(2): 439-450, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31063662

RESUMO

This study presents an enhanced paper-based analytical device (PAD) for forward and reverse group blood typing. The proposed PAD uses a novel methodology, which provides highly reliable results on a fully cellulose based device. The PAD was printed on different cellulose substrates. These substrates were made of different cellulose fibers (sisal and eucalyptus), different grammages, refining steps, and wet additive content. Best parameters were chosen to achieve high reliability on both forward and reverse blood typing. The substrates were patterned with five hydrophilic channels and two hydrophobic areas. For reverse blood typing, the hemoagglutination reaction took place on the hydrophobic surface of the paper before being transferred to the paper web, where together with the forward blood typing tests were all washed with saline solution to read the results by elution. This device allows direct read-out of results; the stains show were agglutination happens. Different blood types were in full agreement between the reverse and forward method and in agreement with traditional methods. The time and simplicity of this methodology confirmed its utility.


Assuntos
Tipagem e Reações Cruzadas Sanguíneas/instrumentação , Tipagem e Reações Cruzadas Sanguíneas/métodos , Celulose/química , Aglutinação , Anticorpos/química , Bioensaio , Sangue , Equipamentos e Provisões , Humanos , Interações Hidrofóbicas e Hidrofílicas , Papel , Reprodutibilidade dos Testes , Propriedades de Superfície
8.
Rev. bras. enferm ; 73(5): e20190554, 2020. tab
Artigo em Inglês | LILACS, BDENF - Enfermagem | ID: biblio-1115379

RESUMO

ABSTRACT Objectives: to characterize the homeless families who use a Public Shower Room; identify significant life events/phenomena for the family's transition to homelessness; understand the relationship between significant life events; identify future expectations of respondents. Methods: an exploratory, descriptive study using the interview and thematic content analysis. Sample consisted of public shower room users. Results: mental illness, social, personal and family factors justify the transition of subjects to homelessness. The total absence of hopelessness alternates with expectations for the future based on resilience and hope. Final Considerations: we highlight in the study the self-determination expressed in small expressions of the narrative, on the one hand, as well as aspects related to the evolution of family relationships, on the other.


RESUMEN Objetivos: caracterizar las familias sin-hogar, usuarias de un Balneario Publico; identificar los fenómenos/acontecimientos de vida significativos por la transición de la familia para sin-hogar; comprehender la relación entre los acontecimientos de vida significativos; identificar las expectativas por el futuro de los inquiridos. Métodos: estudio exploratorio, descriptivo, con recurso a la entrevista y la análisis temática de contenido. La muestra fue constituida por usuarios de un Balneario Publico. Resultados: la enfermedad y los factores de orden social, personal y familiar justifican la transición de los sujetos para sin-hogar. La ausencia total de expectativas, marcadas por la desesperanza, alterna con las expectativas futuras asientes en la resiliencia y en la esperanza. Consideraciones Finales: relevamos en el estudio la autodeterminación asiente en pequeñas expresiones de la narrativa, así como los aspectos ligados a la evolución de la unidad familiar.


RESUMO Objetivos: caracterizar as famílias sem-teto utilizadoras de um Balneário Público; identificar os fenômenos/acontecimentos de vida significativos para a transição da família para a condição de sem-teto; compreender a relação entre os acontecimentos de vida significativos; identificar as expectativas para o futuro dos inquiridos. Métodos: estudo exploratório, descritivo utilizando a entrevista e a análise temática de conteúdo. A amostra foi constituída pelos usuários de um Balneário Públic. Resultados: a doença mental, os fatores de ordem social, pessoal e familiar justificam a transição dos sujeitos para a condição de sem-teto. A ausência total de expectativas, marcadas pela desesperança, alterna com as expectativas futuras assentes na resiliência e na esperança. Considerações Finais: relevamos no estudo a autodeterminação expressa em pequenas expressões da narrativa, por um lado, bem como os aspetos ligados à evolução das relações familiares, por outro.


Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Relações Familiares/psicologia , Pessoas Mal Alojadas/psicologia , Entrevistas como Assunto/métodos , Narração , Pesquisa Qualitativa , Pessoas Mal Alojadas/estatística & dados numéricos
9.
Biotechnol Biofuels ; 12: 161, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31289461

RESUMO

BACKGROUND: The increasing interest in replacing petroleum-based products by more sustainable materials in the packaging sector gives relevance to cellulose as a biodegradable natural resource. Moreover, its properties can be modified physically, chemically or biotechnologically in order to obtain new bioproducts. Refined cotton linters with high cellulose content were treated with hydrolytic (cellulases) and oxidative (LPMO and Laccase_Tempo) enzymes to evaluate their effect on fibre properties and in improving mechanical fibrillation. RESULTS: Cellulases released cellooligosaccharides, reducing fibre length and partially degrading cellulose. They also improved mechanical fibrillation yielding up to 18% of nanofibrillated cellulose (NFC). LPMO introduced a slight amount of COOH groups in cellulose fibres, releasing cellobionic acid to the effluents. The action of cellulases was improved after LPMO treatment; however, the COOH groups created disappeared from fibres. After mechanical fibrillation of LPMO-cellulase-treated cotton linters a 23% yield of NFC was obtained. Laccase_Tempo treatment also introduced COOH groups in cellulose fibres from cotton, yielding 10% of NFC. Degree of polymerization was reduced by Laccase_Tempo, while LPMO treatment did not significantly affect it but produced a higher reduction in fibre length. The combined treatment with LPMO and cellulase provided films with higher transparency (86%), crystallinity (92%), smoothness and improved barrier properties to air and water than films casted from non-treated linters and from commercial NFC. CONCLUSIONS: The combined enzymatic treatment with LPMO and cellulases boosted mechanical fibrillation of cotton linters, improving the NFC production and providing bioproducts with high transparency and high barrier properties.

11.
Issues Ment Health Nurs ; 40(1): 28-32, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30388928

RESUMO

BACKGROUND: In Portugal's capital, Lisbon, there are 19 public showers (PS) attended by a vulnerable population. AIM: To describe the assessment and interventions performed during nursing consultations. METHOD: This is a quantitative, observational, and cross-sectional study. FINDINGS: In a convenience sample of 77 users, 52% are females, 43% are single, 52% do not possess any economic resources, 87% have mental health issues, and 32% are homeless. The main nursing focuses found were: arterial hypertension, disease management skills, and emotional suffering. The most used nursing intervention is listening, followed by the expression of feelings, valuing the individual and his/her story, analyzing causes, providing support, and comforting. CONCLUSIONS: This study shows that the main focus of the nursing care in these facilities is the human being. The respect for individuality and dignity was the primary concern, in an attempt to empower the individual to better manage his/her health and illness processes.


Assuntos
Banhos , Enfermagem em Saúde Comunitária/organização & administração , Serviços de Enfermagem/organização & administração , Logradouros Públicos , Populações Vulneráveis , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Portugal , Fatores Socioeconômicos , Adulto Jovem
12.
J Biomed Mater Res B Appl Biomater ; 107(5): 1533-1541, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30281907

RESUMO

Paper-based microfluidics devices can create a new healthcare model. Cellulose is carbohydrate polymer biocompatible and hydrophilic. These characteristics enhance the development of user-friendly diagnostic devices, but the link between paper manufacturing process and performance of the devices is still unclear. Previous studies focused on either commercial papers or lab papers from wood-cellulose fibers, with different basis-weight. This work introduces the effect of refining process and lab paper from nonwood-cellulose fibers, focusing on sisal fibers to overcome the aforementioned challenge. Structural characteristics of paper, such as basis-weight and degree of refining, are optimized and correlated with blood typing test resolution. Unrefined sisal paper of 50 g/m2 and 100 g/m2 basis-weight exhibit a higher gray intensity level than refined paper, and also maximal capillary rise and a pore size suitable for blood grouping tests. Two different blood types were evaluated with results consistent with the traditional methods, testifying the usefulness of this methodology. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1533-1541, 2019.


Assuntos
Tipagem e Reações Cruzadas Sanguíneas/métodos , Celulose/química , Técnicas Biossensoriais , Coleta de Amostras Sanguíneas , Humanos , Interações Hidrofóbicas e Hidrofílicas , Papel , Porosidade , Sensibilidade e Especificidade , Propriedades de Superfície
13.
Obes Surg ; 28(12): 3935-3942, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30030728

RESUMO

INTRODUCTION/PURPOSE: Adventitial vasa vasorum (VV) expansion to the avascular intima precedes an increase in carotid intima-media thickness. However, factors involved in the development of the atherosclerotic process and its reversibility remain unclear. We aimed to evaluate the VV signal in both morbid obesity and after bariatric surgery (BS). MATERIALS/METHODS: We conducted a case-control study to examine the VV signal in the carotid of 40 morbidly obese patients and 40 non-obese controls. The effect of BS was evaluated in 33 patients. Contrast-enhanced carotid ultrasound was used to assess the VV signal. RESULTS: The mean VV density was higher in obese than in non-obese subjects (0.739 ± 0.117 vs. 0.570 ± 0.111, p < 0.001). The VV signal positively correlated with BMI (p < 0.001) and waist circumference (p = 0.001) but was not related to cIMT. The stepwise multivariate regression analysis revealed that waist circumference (beta = 0.507, p < 0.001) together with fasting plasma glucose (beta = 0.229, p = 0.024) were independently associated with the VV signal (R2 = 0.382). Before BS, the median VV signal correlated with soluble intercellular adhesion molecule 1 (p = 0.022). After a 12-month follow-up, a 12.0% decrease in VV (0.731 ± 0.126 vs. 0.643 ± 0.115, p = 0.003) was observed. In the univariate analysis, the decrease in VV was associated with the baseline VV density (p < 0.001), baseline systolic blood pressure (p = 0.019) and a decrease in sICAM (p = 0.005). However, only baseline systolic pressure (beta = 0.417, p = 0.024) independently predicted the absolute change in VV signal (R2 = 0.174). CONCLUSIONS: Morbidly obesity is associated with increased VV density. In addition, BS appears to reduce the earlier expansion of the adventitial vasa vasorum.


Assuntos
Cirurgia Bariátrica , Artérias Carótidas/diagnóstico por imagem , Obesidade Mórbida/complicações , Obesidade Mórbida/cirurgia , Vasa Vasorum/diagnóstico por imagem , Adulto , Espessura Intima-Media Carotídea , Estudos de Casos e Controles , Meios de Contraste , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/diagnóstico por imagem , Ultrassonografia
14.
Carbohydr Polym ; 194: 43-50, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29801857

RESUMO

Antioxidant activity of xylooligosaccharides (XOS) released from beechwood and birchwood glucuronoxylans by two different xylanases, one from family GH10 (Xyn10A) and another from family GH30 (Xyn30D) was examined. The ABTS (2, 2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) method was used, since it resulted more accurate for the antioxidant activity determination of XOS. Thin layer chromatography and MALDI-TOF MS analysis showed that Xyn10A produced a mixture of neutral and acidic XOS whereas the XOS produced by Xyn30D were all acidic, containing a methylglucuronic acid (MeGlcA) ramification. These acidic XOS, MeGlcA substituted, showed a strongly higher antioxidant activity than the XOS produced by Xyn10A (80% vs. 10% respectively, at 200 µg mL-1). Moreover, the antioxidant activity increased with the degree of polymerization of XOS, and depended on the xylan substrate used. The antioxidant capacity of eucalyptus autohydrolysates after xylanase treatment was also analysed, showing a decrease of their antioxidant activity simultaneous with the decrease in XOS length.


Assuntos
Antioxidantes/metabolismo , Eucalyptus/metabolismo , Glucuronatos/biossíntese , Oligossacarídeos/biossíntese , Xilanos/química , Antioxidantes/química , Endo-1,4-beta-Xilanases/metabolismo , Eucalyptus/química , Glucuronatos/química , Hidrólise , Oligossacarídeos/química , Xilanos/metabolismo
15.
Carbohydr Polym ; 189: 39-47, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29580423

RESUMO

In this work, conditions for an enzymatic pretreatment prior to NCC isolation from cotton linter were assessed. Different cellulase doses and reaction times were studied within an experimental design and NCC were obtained. At optimal enzymatic conditions (20U, 2 h), a total yield greater than 80% was achieved and the necessary enzymatic treatment time was reduced 90%. Different intensities of enzymatic treatments led to proportional decreases in fiber length and viscosity and also were inversely proportional to the amount of released oligosaccharides. These differences within fibers lead to quantitative differences in NCC: increase in acid hydrolysis yield, reduction of NCC surface charge and crystallinity increase. Benefits produced by enzymatic treatments did not have influence over other NCC characteristics such as their sulfur content (≈1%), size (≈200 nm), zeta potential (≈-50 mV) or degree of polymerization (≈200). Evidence presented in this work would reduce the use of harsh sulfuric acid generating a cleaner stream of profitable oligosaccharides.


Assuntos
Celulase/metabolismo , Celulose/metabolismo , Ácidos Sulfúricos/química , Celulase/química , Celulose/química , Oligossacarídeos/química
17.
Carbohydr Polym ; 157: 1488-1495, 2017 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-27987860

RESUMO

In this work, laccase-TEMPO (Lac-T) treatments were applied to bleached commercial dissolving pulp in order to introduce carbonyl and carboxyl groups, which were found to improve dry and wet strength-related properties. Also the solubility behavior towards xanthate reactions was assessed. The effect of a refining step (R) before the oxidative treatment, the absence or presence of oxygen pressure, TEMPO dose (2 or 8% oven dried pulp) and reaction time (8 or 20h) were thoroughly examined. Treatments conducted in the presence of oxygen pressure exhibited greater amount of functional groups. Introducing a pre-refining treatment resulted in similar functional groups but higher wet strength was achieved. Specifically, a high W/D strength ratio was observed, indicating that wet strength-related property was satisfactorily developed. Besides the fact that all Lac-T treatments caused severe cellulose degradation, no fiber strength loss was detected. In fact, all oxidized samples presented higher Wet Zero-Span Tensile Strength, mainly in R+ Lac-T (O2) sample, which suggested the formation of hemiacetal linkages between the new introduced aldehyde groups and available free hydroxyl groups resulting from fibrillation.


Assuntos
Celulose/metabolismo , Óxidos N-Cíclicos/metabolismo , Lacase/metabolismo , Ciência dos Materiais , Oxirredução
18.
J Cardiovasc Nurs ; 31(2): E1-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25829137

RESUMO

BACKGROUND: Subjects with type 2 diabetes mellitus are considered to be at high risk for cardiovascular disease. The identification of carotid atherosclerosis is a validated surrogate marker of cardiovascular disease. Nurses are key professionals in the improvement and intensification of cardiovascular preventive strategies. AIMS: The aim is to study the presence of carotid atherosclerosis in a group of asymptomatic subjects with type 2 diabetes mellitus and no previous clinical cardiovascular disease. METHODS: A total of 187 patients with type 2 diabetes mellitus and 187 age- and sex-matched subjects without type 2 diabetes mellitus were studied in this cross-sectional, observational, cohort study. Standard operational procedures were applied by the nursing team regarding physical examination and carotid ultrasound assessment. Common, bulb, and internal carotid arteries were explored by measuring intima-media thickness and identifying atherosclerotic plaques. RESULTS: Carotid intima-media thickness (c-IMT) and carotid plaque prevalence were significantly greater in diabetic subjects than in the control group. Carotid plaques and c-IMT were more frequent in men than in women and increased with increasing age. In the multivariate analysis, age, gender, waist circumference, systolic blood pressure, and hypercholesterolemia were positively associated with c-IMT, whereas age, gender, and weight were positively associated with carotid plaque. CONCLUSION: The current nurse-led study shows that subjects with type 2 diabetes mellitus have a high prevalence of subclinical atherosclerosis that is associated with cardiovascular risk factors.


Assuntos
Aterosclerose/etiologia , Espessura Intima-Media Carotídea , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/fisiopatologia , Idoso , Aterosclerose/diagnóstico por imagem , Artérias Carótidas/diagnóstico por imagem , Estudos de Casos e Controles , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
19.
Carbohydr Polym ; 133: 302-12, 2015 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-26344285

RESUMO

In this work, treatments with a xylanase (X) and carbohydrases mixture (Cx) were applied on a TCF bleached sisal pulp in order to obtain high-cellulose content fibers applicable on a wide range of uses. A limit of ≈12% w/w final content in hemicelluloses was found regardless of the enzymatic treatment assessed. An extraction with 4% and 9% w/v NaOH was performed for further hemicelluloses removal. We found that NaOH dose could be strongly reduced if combined with Cx or Cx+X treatments. Also, if necessary, a stronger reduction could be obtained with 9% w/v NaOH, which was found to be boosted in a 14% if performed after a treatment with Cx. An end-product with a low content in xylans (≈2.9% w/w) and in HexA (5.8µmol/odp) was obtained. Pulp Fock solubility was also increased (≈30%) by enzymatic treatments. HPLC analysis of effluents provided useful information of enzymatic catalytic mechanisms.


Assuntos
Celulose/química , Glicosídeo Hidrolases/metabolismo , Papel , Agave/química , Biocatálise , Celulose/isolamento & purificação , Endo-1,4-beta-Xilanases/metabolismo , Hidrólise , Hidróxido de Sódio/química
20.
ACS Appl Mater Interfaces ; 7(25): 13834-41, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-26057550

RESUMO

In this work, we studied the influence of the alkyl chain length in enzymatically oxidized gallates on the development of hydrophobicity on paper-based materials, and further correlated the obtained effect to the redox mechanism of the enzymatic treatment. Laccase (Lac) enzyme was used to oxidize various members of the gallate homologous series in the presence or not of lignosulfonates (SL) to produce several functionalization solutions (FS), which were subsequently applied to cellulosic substrates. The hydrophobicity of the substrates was then assessed by means of water drop test (WDT) and contact angle (WCA) measurements. Hydrophobicity peaked reaching WDT and WCA values around 5000 s and 130°, respectively, and then decreased with increasing length of the hydrocarbon chain of gallate. Cyclic voltrammetry (CV) was used to study the effect of SL on the redox reactions of several gallates. The intensity of the anodic peak in their voltammograms decreased increasing the chain length of the gallate. The electrochemical behavior of lauryl gallate (LG) differed from that of other gallates. The fact that the voltammetric curves for SL and LG intersected at a potential of 478 mV indicates an enhancing effect of SL on LG oxidation at high potentials (above 478 mV).


Assuntos
Celulose/química , Ácido Gálico/análogos & derivados , Ácido Gálico/química , Técnicas Eletroquímicas , Eletrodos , Ácido Gálico/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Lacase/metabolismo , Oxirredução
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