515 research outputs found
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Role of flavonoids and nitrates in cardiovascular health
CVD remain the leading cause of death globally. Effective dietary strategies for their reduction are of high priority. Increasing evidence suggests that phytochemicals, particularly dietary flavonoids and nitrates, are key modulators of CVD risk reduction through impact on multiple risk factors. The aim of this review is to explore the evidence for the impact of flavonoid- and nitrate-rich foods and supplements on CVD risk, with specific reference to their importance as mediators of vascular health and platelet function. There is accumulating evidence to support benefits of dietary flavonoids on cardiovascular health. Dose-dependent recovery of endothelial function and lowering of blood pressure have been reported for the flavanol (-)-epicatechin, found in cocoa, apples and tea, through production and availability of endothelial nitric oxide (NO). Furthermore, flavonoids, including quercetin and its metabolites, reduce in vitro and ex vivo platelet function via inhibition of phosphorylation-dependent cellular signalling pathways, although further in vivo studies are required to substantiate these mechanistic effects. Hypotensive effects of dietary nitrates have been consistently reported in healthy subjects in acute and chronic settings, although there is less evidence for these effects in patient groups. Proposed mechanisms of actions include endothelial-independent NO availability, which is dependent on the entro-salivary circulation and microbial conversion of dietary nitrate to nitrite in the mouth. In conclusion, flavonoid- and nitrate-rich foods show promising effects on vascular function, yet further randomly controlled studies are required to confirm these findings and to determine effective doses
Geometric phases in open tripod systems
We first consider stimulated Raman adibatic passages (STIRAP) in a closed
four-level tripod system. In this case, the adiabatic eigenstates of the system
acquire real geometric phases. When the system is open and subject to
decoherence they acquire complex geometric phases that we determine by a Monte
Carlo wave function approach. We calculate the geometric phases and the state
evolution in the closed as well as in the open system cases and describe the
deviation between these in terms of the phases acquired. When the system is
closed, the adiabatic evolution implements a Hadamard gate. The open system
implements an imperfect gate and hence has a fidelity below unity. We express
this fidelity in terms of the acquired geometric phases.Comment: 10 pages 7 figure
Efficient qubit detection using alkali earth metal ions and a double STIRAP process
We present a scheme for robust and efficient projection measurement of a
qubit consisting of the two magnetic sublevels in the electronic ground state
of alkali earth metal ions. The scheme is based on two stimulated Raman
adiabatic passages (STIRAP) involving four partially coherent laser fields. We
show how the efficiency depends on experimentally relevant parameters: Rabi
frequencies, pulse widths, laser linewidths, one- and two-photon detunings,
residual laser power, laser polarization and ion motion.Comment: 14 pages, 15 figure
Comprehensive analysis of the start-up period of a full-scale drinking water biofilter provides guidance for optimization
Abstract. The use of biofilters to produce drinking water from anaerobic groundwater is widespread in some European countries. A major disadvantage of biofilters is the long start-up period required for virgin filter medium to become fully functional. Although individual aspects of biofilter start-up have previously been investigated, no comprehensive study in full-scale using inherent inoculation has previously been documented. A thorough investigation of a full-scale drinking water biofilter was carried out over 10 weeks of start-up. The many spatial and temporal changes taking place during start-up were documented using a holistic approach. In addition to collection of many samples over time (frequency) and space (filter depth), this study entailed the use of multiple sample media (water, backwash water and filter media) and multiple types of analyses (physical, chemical and microbiological). The decrease in filter effluent concentrations of individual substances to compliance levels followed a specific order that was shown to coincide with the spatial-temporal development of bacteria on the filter media. Due to the abiotic nature of the iron removal process, iron disappears first followed by substances that require growth of microorganisms: ammonium, with nitrite appearing briefly near the end of ammonium removal, then manganese. The thorough overall picture obtained by these efforts provides guidance for optimization and monitoring of the start-up. Guidance include to shorten the start-up by focusing on kick-start of the ammonium removal, to limit the monitoring burden to at-line measurements of ammonium in finished water samples supplemented with manual manganese measurements when ammonium removal is complete, and to improve filter design by isolating the removal processes in separate, smaller filters.
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Public health implications of milk fats: the current evidence base and future directions
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Plenary Lecture 2: Milk and dairy produce and CVD: new perspectives on dairy and cardiovascular health
Cardiovascular diseases (CVD) are the leading cause of mortality and morbidity worldwide. One of the key dietary recommendations for CVD prevention is reduction of saturated fat intake. Yet despite milk and dairy foods contributing on average 27 % of saturated fat intake in the UK diet, evidence from prospective cohort studies does not support a detrimental effect of milk and dairy foods on risk of CVD. This paper provides a brief overview of the role of milk and dairy products in the diets of UK adults, and will summarise the evidence in relation to the effects of milk and dairy consumption on CVD risk factors and mortality. The majority of prospective studies and meta-analyses examining the relationship between milk and dairy product consumption and risk of CVD show that milk and dairy products, excluding butter, are not associated with detrimental effects on CVD mortality or risk biomarkers, that include serum LDL cholesterol. In addition, there is increasing evidence that milk and dairy products are associated with lower blood pressure and arterial stiffness. These apparent benefits of milk and dairy foods have been attributed to their unique nutritional composition, and suggest that the elimination of milk and dairy may not be the optimum strategy for CVD risk reduction
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Diet Quality Index for older adults (DQI-65) : development and use in predicting adherence to dietary recommendations and health markers in the UK National Diet and Nutrition Survey
© The Authors 2021. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1017/S0007114521005043Diet quality indexes (DQIs) are useful tools for assessing diet quality in relation to health and guiding delivery of personalised nutritional advice, however existing DQIs are limited in their applicability to older adults (aged ≥65 years). Therefore, this research aimed to develop a novel evidence-based DQI specific to older adults (DQI-65). Three DQI-65 variations were developed to assess the impacts of different component quantitation methods and inclusion of physical activity. The variations were: Nutrient and Food-based DQI-65 (NFDQI-65), NFDQI-65 with Physical Activity (NFDQI-65+PA) and Food-based DQI-65 with Physical Activity (FDQI-65+PA). To assess their individual efficacy, the NFDQI-65, NFDQI-65+PA and FDQI-65+PA were explored alongside the validated Healthy Eating Index-2015 (HEI-2015) and Alternative Healthy Eating Index-2010 (AHEI-2010) using data from the cross-sectional UK National Diet and Nutrition Survey (NDNS) rolling programme. Scores for DQI-65 variations, the HEI-2015 and AHEI-2010 were calculated for adults ≥65 years from years 2-6 of the NDNS (n=871). Associations with nutrient intake, nutrient status and health markers were analysed using linear and logistic regression. Higher DQI-65s and HEI-2015 scores were associated with increased odds of meeting almost all of our previously proposed age-specific nutritional recommendations, and with health markers of importance for older adults, including lower body mass index, lower medication use and lower C-reactive protein (P<0.01). Few associations were observed for the AHEI-2010. This analysis suggests value of all three DQI-65s as measures of dietary quality in UK older adults. However, methodological limitations mean further investigations are required to assess validity and reliability of the DQI-65s.Peer reviewedFinal Accepted Versio
FEVR-Like Presentation of Homocystinuria
A male infant with a diagnosis of homocystinuria presented with avascularity of the peripheral retina with a ridge on ophthalmic exam, consistent with a FEVR-like manifestation homocystinuria. Upon follow-up and treatment for homocystinuria, the retinal vascularity improved without the need for prophylactic treatment to the peripheral avascular retina
Heme Oxygenase, Inflammation, and Fibrosis: The Good, the Bad, and the Ugly?
Upon injury, prolonged inflammation and oxidative stress may cause pathological wound healing and fibrosis, leading to formation of excessive scar tissue. Fibrogenesis can occur in most organs and tissues and may ultimately lead to organ dysfunction and failure. The underlying mechanisms of pathological wound healing still remain unclear, and are considered to be multifactorial, but so far, no efficient anti-fibrotic therapies exist. Extra- and intracellular levels of free heme may be increased in a variety of pathological conditions due to release from hemoproteins. Free heme possesses pro-inflammatory and oxidative properties, and may act as a danger signal. Effects of free heme may be counteracted by heme-binding proteins or by heme degradation. Heme is degraded by heme oxygenase (HO) that exists as two isoforms: inducible HO-1 and constitutively expressed HO-2. HO generates the effector molecules biliverdin/bilirubin, carbon monoxide, and free iron/ferritin. HO deficiency in mouse and man leads to exaggerated inflammation following mild insults, and accumulating epidemiological and preclinical studies support the widely recognized notion of the cytoprotective, anti-oxidative, and anti-inflammatory effects of the activity of the HO system and its effector molecules. In this review, we address the potential effects of targeted HO-1 induction or administration of HO-effector molecules as therapeutic targets in fibrotic conditions to counteract inflammatory and oxidative insults. This is exemplified by various clinically relevant conditions, such as hypertrophic scarring, chronic inflammatory liver disease, chronic pancreatitis, and chronic graft rejection in transplantation
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