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1.
Chimia (Aarau) ; 77(12): 836-841, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38131407

RESUMO

Plastics materials are essential in every part of our lives, resulting in their increasing production and consumption. Consequently, recycling of plastics has been of great importance in the last decades. Among all types of plastics, polyesters have become very appealing for numerous kinds of applications, making their recycling crucial. Several techniques have been developed for the recycling of plastics with the aim of eliminating the waste accumulated, as well as to create a circular economy.

2.
RSC Sustain ; 1(3): 494-503, 2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37215582

RESUMO

Metal-Organic Framework (MOF)-derived TiO2, synthesised through the calcination of MIL-125-NH2, is investigated for its potential as a CO2 photoreduction catalyst. The effect of the reaction parameters: irradiance, temperature and partial pressure of water was investigated. Using a two-level design of experiments, we were able to evaluate the influence of each parameter and their potential interactions on the reaction products, specifically the production of CO and CH4. It was found that, for the explored range, the only statistically significant parameter is temperature, with an increase in temperature being correlated to enhanced production of both CO and CH4. Over the range of experimental settings explored, the MOF-derived TiO2 displays high selectivity towards CO (98%), with only a small amount of CH4 (2%) being produced. This is notable when compared to other state-of-the-art TiO2 based CO2 photoreduction catalysts, which often showcase lower selectivity. The MOF-derived TiO2 was found to have a peak production rate of 8.9 × 10-4 µmol cm-2 h-1 (2.6 µmol g-1 h-1) and 2.6 × 10-5 µmol cm-2 h-1 (0.10 µmol g-1 h-1) for CO and CH4, respectively. A comparison is made to commercial TiO2, P25 (Degussa), which was shown to have a similar activity towards CO production, 3.4 × 10-3 µmol cm-2 h-1 (5.9 µmol g-1 h-1), but a lower selectivity preference for CO (3 : 1 CH4 : CO) than the MOF-derived TiO2 material developed here. This paper showcases the potential for MIL-125-NH2 derived TiO2 to be further developed as a highly selective CO2 photoreduction catalyst for CO production.

3.
Stroke Res Treat ; 2022: 8185893, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36345552

RESUMO

Background: Motor (re)learning via technology-dependent therapy has the potential to complement traditional therapies available to older adults living with stroke after hospital discharge and increase therapy dose. To date, little is known about the feasibility of technology-dependent therapy in a home setting for this population. Objective: To develop a technology-dependent therapy that provides mental and physical training for older adults with stroke and assess feasibility. Specifically we ask, "Can it work"? Design: Single group repeated measures. Methods: 13 participants, aged 18 years and over, were recruited over a six-month period. All participants had mild upper limb impairment following a stoke and were no longer receiving intensive rehabilitation. All participants received 18 days of technology-dependent therapy in their own home. Information was gathered on recruitment and retention, usability, and suitability of outcome measures. Results: 11 participants completed the study. The recruitment rate (number recruited/number canvassed; 10.7%) suggests 1907 participants would need to be canvassed to recruit the necessary sample size (n = 204) for a definitive trial designed to provide 90% power at 5% level of significance to detect a clinically meaningful difference of 5.7 points on the Action Research Arm Test. The usability of the application was rated as exceptional on the System Usability Scale. Effectiveness cannot be determined from this study; however, there was a trend for improvement in measures of upper limb function and emotional well-being. Limitations. The study was limited by a relatively small sample size and lack of control group. Conclusions: This study demonstrated proof of concept of a technology-dependent therapy for upper limb rehabilitation following stroke. The data suggest a definitive trial is feasible, additional strategies to improve recruitment should be considered. Outcome measures aligned with the residual motor function of participants are required.

4.
J Neurosci Methods ; 382: 109728, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36244524

RESUMO

BACKGROUND: A device for moving the head during MR imaging, called a Weighted Head Accelerator Mechanism (WHAM), rotates the head of a supine subject within programmable rotation limits and acceleration profiles. The WHAM can be used with custom MRI sequences to visualize the deformation and recoil of in vivo brain parenchyma with high temporal resolution, allowing element-wise calculation of strain and shear forces in the brain. Unlike previous devices, the WHAM can be configured to provide a wide range of motion and acceleration profiles. NEW METHOD: The WHAM was calibrated using a high-speed camera on a laboratory bench and in 1.5 Tesla and 3.0 Tesla MRI scanners using gel phantoms and human subjects. The MR imaging studies employed a spatial spin-saturation tagging sub-sequence, followed by serial image acquisition. In these studies, 256 images were acquired with a temporal resolution of 2.56 ms. Deformation of the brain was quantified by following the spatial tags in the images. RESULTS: MR imaging showed that the WHAM drove quantifiable brain motions using g forces less than those typically observed in day-to-day activities, with peak accelerations of ∼250 rad/sec2. COMPARISON WITH EXISTING METHODS: The peak pre-contact accelerations and velocities achieved by the WHAM device in this study are both higher than devices used in previous studies, while also allowing for modification of these factors. CONCLUSIONS: MR imaging performed with the WHAM provides a direct method to visualize and quantify "brain slosh" in response to rotational acceleration. Consequently, this approach might find utility in evaluating strategies to protect the brain from mild traumatic brain injury (mTBI).


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Cabeça , Aceleração , Reologia
5.
Chem Mater ; 34(9): 3893-3901, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35573112

RESUMO

Mg-Al mixed metal oxides (MMOs), derived from the decomposition of layered double hydroxides (LDHs), have been purposed as adsorbents for CO2 capture of industrial plant emissions. To aid in the design and optimization of these materials for CO2 capture at 200 °C, we have used a combination of solid-state nuclear magnetic resonance (ssNMR) and density functional theory (DFT) to characterize the CO2 gas sorption products and determine the various sorption sites in Mg-Al MMOs. A comparison of the DFT cluster calculations with the observed 13C chemical shifts of the chemisorbed products indicates that mono- and bidentate carbonates are formed at the Mg-O sites with adjacent Al substitution of an Mg atom, while the bicarbonates are formed at Mg-OH sites without adjacent Al substitution. Quantitative 13C NMR shows an increase in the relative amount of strongly basic sites, where the monodentate carbonate product is formed, with increasing Al/Mg molar ratios in the MMOs. This detailed understanding of the various basic Mg-O sites presented in MMOs and the formation of the carbonate, bidentate carbonate, and bicarbonate chemisorbed species yields new insights into the mechanism of CO2 adsorption at 200 °C, which can further aid in the design and capture capacity optimization of the materials.

6.
Commun Chem ; 5(1): 170, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36697847

RESUMO

The synthesis of metal-organic frameworks (MOFs) is often complex and the desired structure is not always obtained. In this work, we report a methodology that uses a joint machine learning and experimental approach to optimize the synthesis conditions of Al-PMOF (Al2(OH)2TCPP) [H2TCPP = meso-tetra(4-carboxyphenyl)porphine], a promising material for carbon capture applications. Al-PMOF was previously synthesized using a hydrothermal reaction, which gave a low throughput yield due to its relatively long reaction time (16 hours). Here, we use a genetic algorithm to carry out a systematic search for the optimal synthesis conditions and a microwave-based high-throughput robotic platform for the syntheses. We show that, in just two generations, we could obtain excellent crystallinity and yield close to 80% in a much shorter reaction time (50 minutes). Moreover, by analyzing the failed and partially successful experiments, we could identify the most important experimental variables that determine the crystallinity and yield.

7.
ACS Appl Mater Interfaces ; 13(48): 57118-57131, 2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34817166

RESUMO

Metal-organic frameworks (MOFs) are promising materials for the photocatalytic H2 evolution reaction (HER) from water. To find the optimal MOF for a photocatalytic HER, one has to consider many different factors. For example, studies have emphasized the importance of light absorption capability, optical band gap, and band alignment. However, most of these studies have been carried out on very different materials. In this work, we present a combined experimental and computation study of the photocatalytic HER performance of a set of isostructural pyrene-based MOFs (M-TBAPy, where M = Sc, Al, Ti, and In). We systematically studied the effects of changing the metal in the node on the different factors that contribute to the HER rate (e.g., optical properties, the band structure, and water adsorption). In addition, for Sc-TBAPy, we also studied the effect of changes in the crystal morphology on the photocatalytic HER rate. We used this understanding to improve the photocatalytic HER efficiency of Sc-TBAPy, to exceed the one reported for Ti-TBAPy, in the presence of a co-catalyst.

8.
ACS Appl Mater Interfaces ; 13(12): 14239-14247, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33749235

RESUMO

A strategy for enhancing the photocatalytic performance of MOF-based systems (MOF: metal-organic framework) is developed through the construction of MOF/MOF heterojunctions. The combination of MIL-167 with MIL-125-NH2 leads to the formation of MIL-167/MIL-125-NH2 heterojunctions with improved optoelectronic properties and efficient charge separation. MIL-167/MIL-125-NH2 outperforms its single components MIL-167 and MIL-125-NH2, in terms of photocatalytic H2 production (455 versus 0.8 and 51.2 µmol h-1 g-1, respectively), under visible-light irradiation, without the use of any cocatalysts. This is attributed to the appropriate band alignment of these MOFs, the enhanced visible-light absorption, and long charge separation within MIL-167/MIL-125-NH2. Our findings contribute to the discovery of novel MOF-based photocatalytic systems that can harvest solar energy and exhibit high catalytic activities in the absence of cocatalysts.

9.
Chem Soc Rev ; 50(5): 3143-3177, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33475661

RESUMO

Pyrene is one of the most widely investigated aromatic hydrocarbons given to its unique optical and electronic properties. Hence, pyrene-based ligands have been attractive for the synthesis of metal-organic frameworks (MOFs) in the last few years. In this review, we will focus on the most important characteristics of pyrene, in addition to the development and synthesis of pyrene-based molecules as bridging ligands to be used in MOF structures. We will summarize the synthesis attempts, as well as the post-synthetic modifications of pyrene-based MOFs by the incorporation of metals or ligands in the structure. The discussion of promising results of such MOFs in several applications; including luminescence, photocatalysis, adsorption and separation, heterogeneous catalysis, electrochemical applications and bio-medical applications will be highlighted. Finally, some insights and future prospects will be given based on the studies discussed in the review. This review will pave the way for the researchers in the field for the design and development of novel pyrene-based structures and their utilization for different applications.

10.
Chem Sci ; 11(16): 4164-4170, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-34122879

RESUMO

Metal organic frameworks (MOFs) are increasingly used in applications that rely on the optical and electronic properties of these materials. These applications require a fundamental understanding on how the structure of these materials, and in particular the electronic interactions of the metal node and organic linker, determines these properties. Herein, we report a combined experimental and computational study on two families of lanthanide-based MOFs: Ln-SION-1 and Ln-SION-2. Both comprise the same metal and ligand but with differing structural topologies. In the Ln-SION-2 series the optical absorption is dominated by the ligand and using different lanthanides has no impact on the absorption spectrum. The Ln-SION-1 series shows a completely different behavior in which the ligand and the metal node do interact electronically. By changing the lanthanide in Ln-SION-1, we were able to tune the optical absorption from the UV region to absorption that includes a large part of the visible region. For the early lanthanides we observe intraligand (electronic) transitions in the UV region, while for the late lanthanides a new band appears in the visible. DFT calculations showed that the new band in the visible originates in the spatial orbital overlap between the ligand and metal node. Our quantum calculations indicated that Ln-SION-1 with late lanthanides might be (photo)conductive. Experimentally, we confirm that these materials are weakly conductive and that with an appropriate co-catalysts they can generate hydrogen from a water solution using visible light. Our experimental and theoretical analysis provides fundamental insights for the rational design of Ln-MOFs with the desired optical and electronic properties.

11.
Chem Sci ; 12(10): 3587-3598, 2020 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-34163632

RESUMO

Colour is at the core of chemistry and has been fascinating humans since ancient times. It is also a key descriptor of optoelectronic properties of materials and is often used to assess the success of a synthesis. However, predicting the colour of a material based on its structure is challenging. In this work, we leverage subjective and categorical human assignments of colours to build a model that can predict the colour of compounds on a continuous scale. In the process of developing the model, we also uncover inadequacies in current reporting mechanisms. For example, we show that the majority of colour assignments are subject to perceptive spread that would not comply with common printing standards. To remedy this, we suggest and implement an alternative way of reporting colour-and chemical data in general. All data is captured in an objective, and standardised, form in an electronic lab notebook and subsequently automatically exported to a repository in open formats, from where it can be interactively explored by other researchers. We envision this to be key for a data-driven approach to chemical research.

12.
Nature ; 576(7786): 253-256, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31827290

RESUMO

Limiting the increase of CO2 in the atmosphere is one of the largest challenges of our generation1. Because carbon capture and storage is one of the few viable technologies that can mitigate current CO2 emissions2, much effort is focused on developing solid adsorbents that can efficiently capture CO2 from flue gases emitted from anthropogenic sources3. One class of materials that has attracted considerable interest in this context is metal-organic frameworks (MOFs), in which the careful combination of organic ligands with metal-ion nodes can, in principle, give rise to innumerable structurally and chemically distinct nanoporous MOFs. However, many MOFs that are optimized for the separation of CO2 from nitrogen4-7 do not perform well when using realistic flue gas that contains water, because water competes with CO2 for the same adsorption sites and thereby causes the materials to lose their selectivity. Although flue gases can be dried, this renders the capture process prohibitively expensive8,9. Here we show that data mining of a computational screening library of over 300,000 MOFs can identify different classes of strong CO2-binding sites-which we term 'adsorbaphores'-that endow MOFs with CO2/N2 selectivity that persists in wet flue gases. We subsequently synthesized two water-stable MOFs containing the most hydrophobic adsorbaphore, and found that their carbon-capture performance is not affected by water and outperforms that of some commercial materials. Testing the performance of these MOFs in an industrial setting and consideration of the full capture process-including the targeted CO2 sink, such as geological storage or serving as a carbon source for the chemical industry-will be necessary to identify the optimal separation material.

13.
J Am Chem Soc ; 141(15): 6271-6278, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30915844

RESUMO

Targeted modification of electronic structure is an important step in the optimization of metal-organic frameworks (MOFs) for photovoltaic, sensing, and photocatalytic applications. The key parameters to be controlled include the band gap, the absolute energy position of band edges, the excited state charge separation, and degree of hybridization between metal and ligand sites. Partial metal replacement, or metal doping, within secondary building units is a promising, yet relatively unexplored route to modulate these properties in MOFs. Therefore, in the present study, a general method for selecting metal dopant is worked out in theory and validated by experiment, retaining MIL-125 and UiO-66 as the model systems. Metal mixing enables targeted optimization of key electronic structure parameters. This method is applicable to any MOF architecture and can serve as a roadmap for future synthesis of MOFs with predefined properties.

14.
Magn Reson Med ; 82(1): 367-376, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30847967

RESUMO

PURPOSE: Hyperpolarized (HP) media enable biomedical imaging applications that cannot be achieved with conventional MRI contrast agents. Unfortunately, quantifying HP images is challenging, because relaxation and radio-frequency pulsing generate spatially varying signal decay during acquisition. We demonstrate that, by combining center-out k-space sampling with postacquisition keyhole reconstruction, voxel-by-voxel maps of regional HP magnetization decay can be generated with no additional data collection. THEORY AND METHODS: Digital phantom, HP 129 Xe phantom, and in vivo 129 Xe human (N = 4 healthy; N = 2 with cystic fibrosis) imaging was performed using radial sampling. Datasets were reconstructed using a postacquisition keyhole approach in which 2 temporally resolved images were created and used to generate maps of regional magnetization decay following a simple analytical model. RESULTS: Mean, keyhole-derived decay terms showed excellent agreement with the decay used in simulations (R2 = 0.996) and with global attenuation terms in HP 129 Xe phantom imaging (R2 > 0.97). Mean regional decay from in vivo imaging agreed well with global decay values and displayed spatial heterogeneity that matched expected variations in flip angle and oxygen partial pressure. Moreover, these maps could be used to correct variable signal decay across the image volume. CONCLUSIONS: We have demonstrated that center-out trajectories combined with keyhole reconstruction can be used to map regional HP signal decay and to quantitatively correct images. This approach may be used to improve the accuracy of quantitative measures obtained from hyperpolarized media. Although validated with gaseous HP 129 Xe in this work, this technique can be generalized to any hyperpolarized agent.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Processamento de Sinais Assistido por Computador , Adolescente , Adulto , Criança , Pré-Escolar , Meios de Contraste , Fibrose Cística/diagnóstico por imagem , Feminino , Humanos , Pulmão/diagnóstico por imagem , Masculino , Imagens de Fantasmas , Isótopos de Xenônio
16.
J Vis Exp ; (136)2018 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-29985339

RESUMO

We demonstrate a versatile protocol to be used for determining the effectiveness of photocatalysts in degrading indoor air concentration (ppb) volatile organic carbons (VOCs), illustrating this with a titanium dioxide based catalyst, and the VOC 2-propanol. The protocol takes advantage of field asymmetric ion mobility spectroscopy (FAIMS), an analysis tool that is capable of continuously identifying and monitoring the concentration of VOCs such as 2-propanol and acetone at the ppb level. The continuous nature of FAIMS allows detailed kinetic analysis, and long-term reactions, offering a significant advantage over gas chromatography, a batch process traditionally used in air purification characterization. The use of FAIMS in photocatalytic air purification has only recently been used for the first time, and with the protocol illustrated here, the flexibility in allowing alternative VOCs and photocatalysts to be tested using comparable protocols offers a unique system to elucidate photocatalytic air purification reactions at low concentrations.


Assuntos
2-Propanol/química , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental/métodos , Espectrometria de Mobilidade Iônica/métodos , Processos Fotoquímicos
17.
Diabetologia ; 61(8): 1734-1747, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29789878

RESUMO

AIMS/HYPOTHESIS: In line with current advice, we assessed the effect of replacing carbohydrate consumption with mixed nut consumption, as a source of unsaturated fat, on cardiovascular risk factors and HbA1c in type 2 diabetes. The data presented here are from a paper that was retracted at the authors' request ( https://doi.org/10.2337/dc16-rt02 ) owing to lack of adjustment for repeated measures in the same individual. Our aim, therefore, was to fix the error and add new complementary data of interest, including information on clotting factors and LDL particle size. METHODS: A total of 117 men and postmenopausal women with type 2 diabetes who were taking oral glucose-lowering agents and with HbA1c between 47.5 and 63.9 mmol/mol (6.5-8.0%) were randomised after stratification by sex and baseline HbA1c in a parallel design to one of three diets for 3 months: (1) 'full-dose nut diet' (n = 40): a diet with 2.0 MJ (477 kcal) per 8.4 MJ (2000 kcal) energy provided as mixed nuts (75 g/day); (2) 'full-dose muffin diet' (n = 39): a diet with 1.97 MJ (471 kcal) per 8.4 MJ (2000 kcal) energy provided as three whole-wheat muffins (188 g/day), with a similar protein content to the nuts, and the same carbohydrate-derived energy content as the monounsaturated fatty acid-derived energy content in the nuts; or (3) 'half-dose nut diet' (n = 38): a diet with 1.98 MJ (474 kcal) per 8.4 MJ (2000 kcal) energy provided as half portions of both the nuts and muffins. The primary outcome was change in HbA1c. The study was carried out in a hospital clinical research centre and concluded in 2008. Only the statistician, study physicians and analytical technicians could be blinded to the group assessment. RESULTS: A total of 108 participants had post-intervention data available for analysis (full-dose nut group, n = 40; full-dose muffin group, n = 35; half-dose nut group, n = 33). Compared with the full-dose muffin diet, the full-dose nut diet provided 9.2% (95% CI 7.1, 11.3) greater total energy intake from monounsaturated fat. The full-dose nut diet (median intake, 75 g/day) also reduced HbA1c compared with the full-dose muffin diet by -2.0 mmol/mol (95% CI -3.8, -0.3 mmol/mol) (-0.19% [95% CI -0.35%, -0.02%]), (p = 0.026). Estimated cholesterol levels in LDL particles with a diameter <255 ångström [LDL-c<255Å]) and apolipoprotein B were also significantly decreased after the full-dose nut diet compared with the full-dose muffin diet. According to the dose response, the full-dose nut diet is predicted to reduce HbA1c (-2.0 mmol/mol [-0.18%]; p = 0.044), cholesterol (-0.25 mmol/l; p = 0.022), LDL-cholesterol (-0.23 mmol/l; p = 0.019), non-HDL-cholesterol (-0.26 mmol/l; p = 0.020), apolipoprotein B (-0.06 g/l, p = 0.013) and LDL-c<255Å (-0.42 mmol/l; p < 0.001). No serious study-related adverse events occurred, but one participant on the half-dose nut diet was hospitalised for atrial fibrillation after shovelling snow. CONCLUSIONS/INTERPRETATION: Nut intake as a replacement for carbohydrate consumption improves glycaemic control and lipid risk factors in individuals with type 2 diabetes. TRIAL REGISTRATION: ClinicalTrials.gov NCT00410722 FUNDING: The study was funded by the International Tree Nut Council Nutrition Research and Education Foundation, the Peanut Institute, Loblaw Companies and the Canada Research Chairs Program of the Government of Canada.


Assuntos
Diabetes Mellitus Tipo 2/terapia , Dieta para Diabéticos , Carboidratos da Dieta , Nozes , Idoso , Apolipoproteínas/sangue , Fatores de Coagulação Sanguínea/metabolismo , Glicemia/análise , Pressão Sanguínea , Peso Corporal , LDL-Colesterol/sangue , Interpretação Estatística de Dados , Dieta , Feminino , Análise de Alimentos , Humanos , Lipídeos/sangue , Lipoproteínas LDL/química , Masculino , Pessoa de Meia-Idade , Tamanho da Partícula , Reprodutibilidade dos Testes
18.
J Am Coll Cardiol ; 69(9): 1103-1112, 2017 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-28254171

RESUMO

BACKGROUND: Dietary recommendations emphasize increased consumption of fruit, vegetables, and whole grain cereals for prevention of chronic disease. OBJECTIVES: This study assessed the effect of dietary advice and/or food provision on body weight and cardiovascular disease risk factors. METHODS: Healthy overweight men (n = 209) and women (n = 710), mean age 44.7 years, body mass index [BMI] 32.4 kg/m2, were randomized between November 2005 and August 2009 to receive Health Canada's food guide (control, n = 486) or 1 of 3 interventions: dietary advice consistent with both Dietary Approaches to Stop Hypertension (DASH) and dietary portfolio principles (n = 145); weekly food provision reflecting this advice (n = 148); or food delivery plus advice (n = 140). Interventions lasted 6 months with 12-month follow-up. Semiquantitative food frequency questionnaires and fasting blood, anthropometric and blood pressure measurements were obtained at baseline, 6 months, and 18 months. RESULTS: Participant retention at 6 and 18 months was 91% and 81%, respectively, after food provision compared to 67% and 57% when no food was provided (p < 0.0001). Test and control treatments showed small reductions in body weight (-0.8 to -1.2 kg), waist circumference (-1.1 to -1.9 cm), and mean arterial pressure (0.0 to -1.1 mm Hg) at 6 months and Framingham coronary heart disease risk score at 18 months (-0.19 to -0.42%), which were significant overall. Outcomes did not differ among test and control groups. CONCLUSIONS: Provision of foods increased retention but only modestly increased intake of recommended foods. Current dietary recommendations showed small overall benefits in coronary heart disease risk factors. Additional dietary strategies to maximize these benefits are required. (Fruits, Vegetables, and Whole Grains: A Community-based Intervention; NCT00516620).


Assuntos
Doenças Cardiovasculares/prevenção & controle , Dieta , Sobrepeso/dietoterapia , Redução de Peso , Adulto , Índice de Massa Corporal , Canadá , Feminino , Frutas , Humanos , Masculino , Pessoa de Meia-Idade , Sobrepeso/complicações , Cooperação do Paciente , Fatores de Risco , Verduras , Grãos Integrais
19.
BMJ Open ; 7(3): e015026, 2017 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-28336747

RESUMO

OBJECTIVE: To assess associations between dietary intake and carotid intima media thickness (CIMT) by carotid ultrasound (CUS), a surrogate marker of cardiovascular disease (CVD) risk, in those with type 2 diabetes. DESIGN: Cross-sectional analysis of baseline data from 325 participants from three randomised controlled trials collected in the same way. SETTING: Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Canada. PARTICIPANTS: 325 participants with type 2 diabetes, taking oral antidiabetic agents, with an HbA1c between 6.5% and 8.0% at screening, without a recent cardiovascular event. MAIN OUTCOME MEASURES: CIMT by CUS and associations with dietary intake from 7-day food records, as well as anthropometric measures and fasting serum samples. RESULTS: CIMT was significantly inversely associated with dietary pulse intake (ß=-0.019, p=0.009), available carbohydrate (ß=-0.004, p=0.008), glycaemic load (ß=-0.001, p=0.007) and starch (ß=-0.126, p=0.010), and directly associated with total (ß=0.004, p=0.028) and saturated (ß=0.012, p=0.006) fat intake in multivariate regression models adjusted for age, smoking, previous CVD event, blood pressure medication, antidiabetic medication and ultrasonographer. CONCLUSIONS: Lower CIMT was significantly associated with greater consumption of dietary pulses and carbohydrates and lower total and saturated fat intake, suggesting a potential role for diet in CVD risk management in type 2 diabetes. Randomised controlled trials are anticipated to explore these associations further. TRIAL REGISTRATION NUMBER: NCT01063374.


Assuntos
Espessura Intima-Media Carotídea/estatística & dados numéricos , Diabetes Mellitus Tipo 2/fisiopatologia , Dieta/métodos , Canadá , Doenças Cardiovasculares , Estudos Transversais , Dieta/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
20.
JPEN J Parenter Enteral Nutr ; 41(8): 1386-1392, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-27503934

RESUMO

BACKGROUND: Establishing postnatal nutrition delivery is challenging in neonates with immature sucking and swallowing ability. Enteral feeding is the gold standard for such patients, but their small size and fragility present challenges in nasogastric (NG) feeding tube placement. Feeding tubes are typically placed with x-ray guidance, which provides minimal soft tissue contrast and exposes the baby to ionizing radiation. This research investigates magnetic resonance (MR) guidance of NG feeding tube placement in neonates to provide improved soft tissue visualization without ionizing radiation. MATERIALS AND METHODS: A novel feeding tube incorporating 3 solenoid coils for real-time tracking and guidance in the MR environment was developed. The feeding tube was placed 5 times in a rabbit with conventional x-ray guidance to assess mechanical stability and function. After x-ray procedures, the rabbit was transferred to a neonatal MR system, and the tube was placed 5 more times. RESULTS: In procedures guided by x-ray and MR, the feeding tube provided sufficient mechanical strength and functionality to access the esophagus and stomach of the rabbit. MR imaging provided significantly improved soft tissue contrast versus x-ray, which aided in proper tube guidance. Moreover, MR guidance allowed for real-time placement of the tube without the use of ionizing radiation. CONCLUSIONS: The feasibility and benefits offered by an MR-guided approach to NG feeding tube placement were demonstrated. The ability to acquire high-quality MR images of soft tissue without ionizing radiation and a contrast agent, coupled with accurate 3-dimensional device tracking, promises to have a powerful impact on future neonatal feeding tube placements.


Assuntos
Nutrição Enteral , Intubação Gastrointestinal/métodos , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Esôfago/diagnóstico por imagem , Estudos de Viabilidade , Imageamento por Ressonância Magnética , Masculino , Coelhos , Estômago/diagnóstico por imagem
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