Nitrate Consumption Research Articles

A Nitrate-Rich Vegetable Intervention Elevates Plasma Nitrate and Nitrite Concentrations and Reduces Blood Pressure in Healthy Young Adults

BackgroundEmerging evidence suggests that increasing dietary nitrate intake may be an effective approach to reduce blood pressure. Beetroot juice is often used to supplement dietary nitrate, whereas nitrate intake levels from habitual diet are low. An increase in the habitual intake of nitrate-rich vegetables may represent an alternative to nitrate supplementation. However, the effectiveness and acceptability of a nitrate–rich-vegetables diet remain to be established. ObjectiveThe aim was to investigate the effect and feasibility of two different intervention strategies to increase dietary nitrate intake, on plasma nitrate/nitrite concentrations and blood pressure. DesignA randomized, crossover trial was used. ParticipantsParticipants were healthy men and women (both n=15; age: 24±6 years) from the Netherlands. InterventionParticipants were instructed to consume ∼400 mg nitrate at lunch, provided through nitrate-rich vegetables and dietary counseling, or beetroot juice supplementation. Both interventions lasted 1 week, with 1-week washout (January to April 2017). Main outcomePlasma nitrate and nitrite concentrations and resting systolic and diastolic blood pressure were measured in an overnight fasted state (before and after intervention) and ∼2.5 hours after lunch (before and throughout intervention on day 1, 4, and 7). Statistical analysisTwo-factor (time × treatment) repeated-measures analyses of variance were performed. ResultsMean plasma nitrate concentrations increased with both interventions, with a larger increase in beetroot juice vs nitrate-rich vegetables, both in a fasted state and ∼2.5 hours after lunch (day 1, beetroot juice: 2.31±0.56 mg/dL [373±90 μmol/L] vs nitrate-rich vegetables: 1.71±0.83 mg/dL [277±134 μmol/L]; P<0.001). Likewise, mean plasma nitrite concentrations increased with both interventions, but were higher after lunch in beetroot juice than in nitrate-rich vegetables (day 1: 2.58±1.52 μg/dL [560±331 nmol/L] vs 2.15±1.21 μg/dL [468±263 nmol/L]; P=0.020). Fasting mean systolic and diastolic blood pressure did not change, but mean systolic and diastolic blood pressure assessed ∼2.5 hours after lunch were significantly reduced throughout both intervention periods (P<0.05), with no differences between beetroot juice and nitrate-rich vegetables (day 1, systolic blood pressure: –5.1±9.5 mm Hg and diastolic blood pressure: –5.3±8.9 mm Hg). ConclusionShort-term consumption of dietary nitrate in the form of nitrate-rich vegetables represents an effective means to increase plasma nitrate and nitrite concentrations, and reduces blood pressure to the same extent as beetroot juice supplementation.

The Role of NOx in Engine Lubricant Oxidation

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Fuel economy trends like engine downsizing and reduced piston ring tension have created challenging environments for modern engine oils which are expected to deliver more from less. Downsizing has led to smaller sumps meaning longer contact times of the lubricant with NOx in blow-by gasses. Fuel economy requirements have also demanded greater engine efficiency with increasing sump temperatures and blow-by rates due to reduced ring tension. These trends promote nitro-oxidation driven by the action of NOx and air on the lubricant. Nitro-oxidation has often been overlooked as a mechanism of oil oxidation in real world engines. Indeed, in bench oxidation tests purporting to protect modern engines against lubricant oxidation, the emphasis is almost exclusively on iron catalysed oxidation. This paper will show that a simple bench nitro-oxidation test is capable of reproducing trends in nitrate ester formation and consumption seen in real engines and demonstrate that lubricant oxidation and viscosity increase is accounted for by the action of NOx without the use of iron catalysts. This demonstrates that the initiation of lube oil oxidation in real engines is due to the action of NOx and it is only later in the oil life cycle that iron plays any significant role. This has important implications for the widespread use of iron-catalysed bench oxidation tests as guardians for oxidation performance in the real world. Because the oxidation observed in iron catalysed bench oxidation tests does not include NOx, the initiation and propagation of oxidation proceeds via a different mechanism and requires a different anti-oxidant solution.&lt;/div&gt;&lt;/div&gt;

Power to hydrogen-oxidizing bacteria: Effect of current density on bacterial activity and community spectra

Hydrogen-oxidizing bacteria (HOB) can utilize hydrogen, oxygen, and carbon dioxide as electron donor, electron acceptor, and carbon source, respectively. These bacteria can convert hydrogen and carbon dioxide to biomass which is different from hydrophilic denitrification. “Power to HOB”, a new supplementary to “Power to Gas”, was proposed and demonstrated in this study, in which HOB were cultivated via in-situ consuming hydrogen generated by water electrolysis. The objects of this work were to explore the effect of current density on HOB activity and microbial community. The results showed good activity of enriched HOB that the nitrate consumption rate was 21 mg/L/d in batch and continuous modes under the current density (CD) of 2.14 mA/cm2. The cyclic voltammetry curve demonstrated the electric activity of HOB that redox peaks were 0.330 V and 0.195 V at corresponding CDs of 2.14 mA/cm2 and 4.29 mA/cm2, respectively. Finally, the community spectra revealed that the percentage of Cupriavidus sp. TA19 decreased by 15.59% (2.14 mA/cm2 vs 4.29 mA/cm2), and Pseudonocardia sp. YK32 increased by 38.31%. Moreover, Cupriavidus sp. TA19 was reported as HOB for polyhydroxyalkanoate (PHA, degradable plastics) production. Pseudonocardia sp. YK32 was also reported as HOB and the function was unknown. Thus, “Power to HOB” can be a new supplementary to “Power to Gas” and the results extend HOB applications.

No thermoregulatory or ergogenic effect of dietary nitrate among physically inactive males, exercising above gas exchange threshold in hot and dry conditions

The aim of this study was to determine the effect of five days dietary nitrate (NO3 −) consumption on exercise tolerance and thermoregulation during cycling in hot, dry conditions. In a double-blind, randomised crossover design, 11 healthy males participated in an exercise tolerance test (Tlim) in the heat (35°C, 28% relative humidity), cycling above the thermoneutral gas exchange threshold, after five days of dietary supplementation, with either NO3 –rich beetroot juice (BR; ∼ 9.2 mmol NO3 −) or placebo (PLA). Changes in plasma [NO3 −] and nitrite [NO2 −], core and mean skin temperatures, mean local and whole-body sweat rates, heart rate, perceptual ratings and pulmonary gas exchange were measured during exercise, alongside calorimetric estimations of thermal balance. Mean arterial pressures (MAP) were recorded pre-Tlim. There were no differences in Tlim between conditions (BR = 22.8 ± 8.1 min; Placebo = 20.7 ± 7.9 min) (P = 0.184), despite increases in plasma [NO3 −] and [NO2 −] (P < 0.001) and a 3.8% reduction in resting MAP (P = 0.004) in the BR condition. There were no other differences in thermoregulatory, cardio-metabolic, perceptual or calorimetric responses to the Tlim between conditions (P > 0.05). Dietary NO3 − supplementation had no effect on exercise tolerance or thermoregulation in hot, dry conditions, despite reductions in resting MAP and increases in plasma [NO3 −] and [NO2 −]. Healthy, yet physically inactive individuals with no known impairments in vasodilatory and sudomotor function do not appear to require BR for ergogenic or thermolytic effects during exercise in the heat.

The Peculiar Facets of Nitric Oxide as a Cellular Messenger: From Disease-Associated Signaling to the Regulation of Brain Bioenergetics and Neurovascular Coupling.

In this review, we address the regulatory and toxic role of ·NO along several pathways, from the gut to the brain. Initially, we address the role on ·NO in the regulation of mitochondrial respiration with emphasis on the possible contribution to Parkinson's disease via mechanisms that involve its interaction with a major dopamine metabolite, DOPAC. In parallel with initial discoveries of the inhibition of mitochondrial respiration by ·NO, it became clear the potential for toxic ·NO-mediated mechanisms involving the production of more reactive species and the post-translational modification of mitochondrial proteins. Accordingly, we have proposed a novel mechanism potentially leading to dopaminergic cell death, providing evidence that NO synergistically interact with DOPAC in promoting cell death via mechanisms that involve GSH depletion. The modulatory role of NO will be then briefly discussed as a master regulator on brain energy metabolism. The energy metabolism in the brain is central to the understanding of brain function and disease. The core role of ·NO in the regulation of brain metabolism and vascular responses is further substantiated by discussing its role as a mediator of neurovascular coupling, the increase in local microvessels blood flow in response to spatially restricted increase of neuronal activity. The many facets of NO as intracellular and intercellular messenger, conveying information associated with its spatial and temporal concentration dynamics, involve not only the discussion of its reactions and potential targets on a defined biological environment but also the regulation of its synthesis by the family of nitric oxide synthases. More recently, a novel pathway, out of control of NOS, has been the subject of a great deal of controversy, the nitrate:nitrite:NO pathway, adding new perspectives to ·NO biology. Thus, finally, this novel pathway will be addressed in connection with nitrate consumption in the diet and the beneficial effects of protein nitration by reactive nitrogen species.

Abstract P216: Co-ingestion of Dietary Nitrate and Caffeine Elevates Submaximal Oxygen Consumption and Oxygen-pulse Compared to Nitrate or Caffeine Alone

Introduction: Previous studies have examined dietary nitrate's and caffeine’s combined effects on time-trial and peak power output with caffeine improving performance while nitrate exhibits no additive benefit with co-ingestion. However, less is known about their combined effect on submaximal intensity exercise. Dietary nitrate may reduce submaximal oxygen cost while caffeine may increase submaximal cost. Hypothesis: Co-ingestion of dietary nitrate may attenuate the rise in oxygen consumption following caffeine intake. Methods: Ten healthy individuals (4 males; 28 ± 10 years of age) and (6 females; 21 ± 3 years of age) participated in a double-blind, placebo controlled, crossover experiment. The first of five visits consisted of a maximal oxygen consumption (VO 2max ) treadmill test. Prior to visits 2 - 5, participants consumed either a dietary nitrate (~12.4 mmol, NIT) or placebo nitrate supplement (PLN) combined with either a caffeine (3 mg/kg, CAF) or placebo caffeine (PLC) dose for a total of 4 days. The final dose of NIT or PLN and CAF or PLC was consumed 2.5 and 1-hr pre-exercise, respectively. Visits 2 - 5 consisted of a 30-min treadmill run at ~65% VO 2max . During exercise, VO 2 and heart rate (HR) were measured continuously. A linear mixed effects model analysis was performed to determine how each supplementation influenced each dependent variable. Treatments (NIT+CAF, CAF+PLN, NIT+PLC, PLN+PLC) and exercise timepoints (10 and 30 min) served as fixed factors. If p&lt;0.05, p ost-hoc pairwise comparisons were performed. Results: Exercise VO 2 was significantly elevated for NIT+CAF at 10 and 30 minutes (36.2±4.1 and 37.7±5.0 ml/kg/min, respectively) compared to placebo (33.4±3.4 and 35.3±3.8 ml/kg/min, respectively) (p&lt;0.05). However, there was no difference in VO2 at either timepoint (10 or 30 minutes) for conditions CAF+PLN (34.3±3.9, 35.4±3.6, and 36.3±3.2 ml/kg/min, respectively) (p=0.07) and NIT+PLC (34.8±3.9, 36.0±4.2, and 36.6±4.4 ml/kg/min, respectively) (p=0.08) compared to PLN+PLC. No difference was observed for heart rate between conditions at any timepoint. However, oxygen-pulse (VO 2 /HR) at the end of exercise was elevated in NIT+CAF (15.1±2.5 ml/beat) compared to CAF+PLN, NIT+PLC, PLN+PLC (14.5±2.5, 14.2±2.5, 13.8±2.5 ml/beat, respectively). Conclusion: When consumed independently, a low-moderate dose of caffeine or dietary nitrate had no impact on oxygen consumption during 30 minutes of moderate intensity exercise. However, co-ingestion of dietary nitrate and caffeine elevated submaximal oxygen consumption compared to a placebo control; both overall (main effect) and at individual time points of 10 and 30 minutes. Additionally, oxygen-pulse was elevated with co-ingestion compared to all treatments perhaps due to enhanced tissue uptake or altered mitochondrial efficiency. Future work may examine such mechanisms.

Increased SCR performance of Cu-CHA due to ammonium nitrate buffer: Experiments with oscillating NO/NO2 ratios and application to real driving cycles

Currently, the literature on ammonium nitrate formation across SCR catalysts mainly sees ammonium nitrate formation as an undesired problem because it can inhibit the catalytic activity. This paper shows that, besides the inhibition effects, ammonium nitrate formation on the catalyst can also positively influence the catalytic activity because it acts as an NO2 buffer that stores NO2 under NO2-excess conditions and releases NO2 under NO2-deficient conditions.To demonstrate the working principle of the ammonium nitrate buffer, in a first step the ammonium nitrate loading is determined as a function of the NO2/NOx ratio in the feed, using a titration scheme recently proposed in the literature. Then, step tests are performed where at otherwise constant feed conditions, the NO2/NOx ratio is switched between 75 % NO2/NOx and 25 % NO2/NOx. During the slow frequency switching (3 min per phase), an increased NOx conversion is observed after both the transition to NO2-rich and NO2-lean. This can be explained by a build-up of ammonium nitrate during NO2-rich and the consumption of ammonium nitrate during NO2-lean conditions owing to the enhanced SCR reaction. When the frequency of the NO2/NOx switches is increased to 30 s, the ammonium nitrate storage loading can no longer follow the fluctuations and stays at an intermediate level. During this scenario, the catalyst shows a constant high conversion close to the Fast SCR reaction.Finally, it is demonstrated that the ammonium nitrate buffer contributes to the overall NOx conversion during standard driving cycles. In particular, the NO2 emissions are predicted significantly better by a model that accounts for the ammonium nitrate storage equilibrium.

The relationship between consumption of nitrite or nitrate and risk of non-Hodgkin lymphoma

Epidemiologic studies of the relationship between nitrite or nitrate consumption and risk of non-Hodgkin lymphoma (NHL) remain controversial. The current meta-analysis aimed to reexamine the evidence and quantitatively evaluate that relationship. Manuscripts were retrieved from the Web of Science, Chinese National Knowledge Infrastructure and PubMed databases up to May 2019. From the studies included in the review, results were combined and presented as odds ratios (OR). To conduct a dose-response (DR) analysis, studies presenting risk estimates over a series of categories of exposure were selected. Our data indicate that the consumption of nitrite was linked to a significantly increased hazard of NHL (OR: 1.37; 95% CI: 1.14–1.65), rather than nitrate (OR: 1.02; 95% CI: 0.94–1.10). According to Egger’s and Begg’s tests (P > 0.05), there was no evidence of significant publication bias. Moreover, our DR analysis indicated that the risk of NHL grew by 26% for each additional microgram of nitrite consumed in the diet per day (OR: 1.26; 95% CI: 1.09–1.42). Through subset analysis of the nitrite studies, data from the high-quality studies indicated that consumption was positively associated with carcinogenicity, leading to NHL (OR: 1.44; 95% CI: 1.17–1.77) and positively correlated with the development of diffuse large B-cell lymphoma (OR: 1.55; 95% CI: 1.07–2.26), but not other NHL subtypes. In addition, the data suggested that females (OR: 1.50; 95% CI: 1.15–1.95) and high levels of nitrite intake (OR: 1.64; 95% CI: 1.28–2.09) had a higher risk of NHL. Our meta-analysis supports the hypothesis that nitrite intake, but not that of nitrate, raises the risk of developing NHL. In the future, better designed prospective research studies should be conducted to confirm our findings, clarify potential biological mechanisms and instruct clinicians about NHL prophylaxis.

The Popeye mythology may be true: eating spinach can make you fatigue resistant!

The Popeye mythology may be true: eating spinach can make you fatigue resistant!

Nitrate sources and the effect of land cover on the isotopic composition of nitrate in the catchment of the Rhône River

ABSTRACTThe Rhône River originates in the high Alps and drains an intensely cultivated and industrialised catchment before it discharges to the Gulf of Lion. We investigated the interaction of catchment geomorphology with nitrate sources (atmosphere, agriculture, and nitrification of soil organic matter) and removal processes in large and diverse watersheds on the basis of dual nitrate isotope signatures in river water.In March 2015, we took surface water samples along the Rhône River, including its main tributaries, and measured nutrient concentrations and the stable isotopic composition of nitrate (δ15N, δ18O and Δ17O), and water (δ18O-H2O).Results show that high altitude regions are dominated by nitrate from nitrification in pristine soils and atmospheric deposition, while nitrate in the downstream Rhône River originates mainly from nitrification of agricultural/urban sources. Parallel increases in δ15N and δ18O reflect the influence of primary production. Previous studies suggested robust correlations between land use and . Based on our observation that nitrate δ15N values at higher altitudes are lower than expected, we assume that lower nitrate δ15N values likely reflect limited nitrate consumption and lower soil nitrogen turnover rates. We propose that correlation between land use and nitrate δ15N is sensitive to slope and geomorphology.

How Important is Denitrification in Riparian Zones? Combining End‐Member Mixing and Isotope Modeling to Quantify Nitrate Removal from Riparian Groundwater

AbstractRiparian zones are important buffer zones for streams as they are hotspots of nitrate transformation and removal in agricultural catchments. However, mixing of water from different sources and various transformation processes can complicate the quantification of nitrate turnover in riparian zones. In this study, we analyzed nitrate concentration and isotope data in riparian groundwater along a 2‐km stream section in central Germany. We developed a mathematical model combining end‐member mixing and isotope modeling to account for mixing of river water and groundwater and quantify nitrate transformation in riparian groundwater. This enabled us to explicitly determine the extent of denitrification (as process leading to permanent nitrate removal from riparian groundwater) and transient nitrate removal by additional processes associated with negligible isotope fractionation (e.g., plant uptake and microbial assimilation) and to perform an extensive uncertainty analysis. Based on the nitrogen isotope data of nitrate, the simulations suggest a mean removal of up to 28% by additional processes and only about 9% by denitrification. Nitrate removal from riparian groundwater by additional processes exceeded denitrification particularly in winter and at larger distance from the river, underlining the role of the river as organic carbon source. This highlights that nitrate consumption by additional processes predominates at the field site, implying that a substantial fraction of agricultural nitrogen input is not permanently removed but rather retained in the riparian zone. Overall, our model represents a useful tool to better compare nitrogen retention to permanent nitrogen removal in riparian zones at various temporal and spatial scales.

Association of daily nitrate consumption with blood pressure and other risk factors for cardiovascular diseases in a representative UK population

AbstractDietary inorganic nitrate has been shown to lower blood pressure (BP) and improve endothelial function(1). The main sources of dietary nitrate are vegetables (root and green leafy varieties) as well as drinking water but data available on dietary analysis software on nitrate levels in vegetables and vegetable-based foods is very limited. To date, very few studies have investigated the relationship between the level of consumption of dietary nitrate on BP and other cardiovascular disease (CVD) risk factors in a representative UK population. The aim of the study was to address this knowledge gap using data from the National Diet and Nutrition Survey (NDNS) years 1–8, a cross-sectional study conducted in 3339 men and women aged 19–64 y between 2008/09–2011/12. A comprehensive database was first developed to evaluate the nitrate and nitrite levels in vegetables, cured meats and composite dishes to more accurately estimate the dietary nitrate intakes of the NDNS participants. The population was then classified into quartiles of daily nitrate intake, with quartile 1 (Q1: 26–106 mg/d) and quartile 4 (Q4: 183–559 mg/d) representing diets with the lowest and highest intakes, respectively. ANCOVA analysis was performed to determine the relationship between the level of daily nitrate intake with available data on biomarkers of CVD risk (including BP (systolic, diastolic and pulse pressure), lipid profile, (total, high-density lipoprotein and low-density lipoprotein (LDL-C) cholesterol), C-reactive protein, anthropometric measures (body mass index and waist to hip ratio) and glycaemic control (glucose and glycated haemoglobin). There were significant differences in systolic (P-trend = 0.008) and diastolic (P-trend = 0.025) BP across increasing quartiles of dietary nitrate intake, with BP significantly lower in Q3 than all other quartiles. Pulse pressure (calculated as systolic–diastolic BP) was also found to be significantly different across quartiles (P-trend = 0.001), with diets of participants in Q3 and Q4 being associated with significantly lower pulse pressures than those in Q1 (P-Q1 vs. Q3 = 0.005, P-Q1 vs. Q4 = 0.007). All of the other CVD risk markers were not different between quartile groups. Our preliminary results suggest that the level of dietary nitrate intake may be significantly associated with BP, a key independent CVD risk factor. There is an urgent need to more accurately estimate the dietary nitrate intake in the UK population and to determine whether the source of dietary nitrate (vegetables vs cured meats) impacts on the significant relationship with BP.

Моделирование влияния удельных расходов аммиачной селитры, фосфоритной муки и хлорида калия на соотношения питательных элементов в npк–удобрениях

Моделирование влияния удельных расходов аммиачной селитры, фосфоритной муки и хлорида калия на соотношения питательных элементов в npк–удобрениях

Influence of Varying Doses and Duration of Dietary Nitrates from Beetroot Juice on Sprint Performance in U.S. Army ROTC Cadets: A pilot study

Objective: Assess the effects of varying levels and duration of dietary nitrate supplementationfrom beetroot juice (BR) on sprint performance in army ROTC cadets.&#x0D; Methods: Army Reserve Officer Training Corps (ROTC) cadets were randomly assigned to oneof three treatment groups: control (CON); low beetroot juice dose (BR1); and high BR juice –BR2. For 0, 6 and 15 days nitrate consumption from BR groups were as follows: CON receivedone 16.9 oz. bottle of apple juice (0 mg NO 3 -); BR1 received one can of BR juice (300 mg, 4.84mmol NO 3 -), and BR2 received 2 cans (16.8 oz.) BR (600 mg, 9.68 mmol NO 3 -). One week priorto the study, each cadet completed body composition measurements, predicted aerobic capacitymeasurements, and nutritional analysis via two 24-hour dietary recalls. Differences in primarymeasures (distance covered in the Yo-Yo IR1) were analyzed with two-way repeated measuresANOVA tests both between groups (CON, BR1, BR2) and within groups (0, 6, and day 15).Descriptive statistics and frequency counts were run on all remaining variables with a one-wayANOVA or t-test, including maximal heart rate during the YoYo IR1, dietary compliance, dailyblood pressure, juice compliance, and conditioning work-outs&#x0D; Results: A dose-related enhancement with BR was observed; the data trended towardssignificance even in this small sample. A t-test revealed that there was a significant difference insprint performance by males and females overall at days 0, 6, 15 (p = 0.025, p = 0.005, p =0.004, respectively).&#x0D; Conclusion: A single (300 mg, 4.84 mmol NO 3 ) or double (600 mg, 9.68 mmol NO 3 -) daily doseconsumption of BR appears to benefit ROTC cadets in athletic performance. Daily consumptionof BR benefitted ROTC males more than females. Results suggest BR supplementation could beadvantageous for sprint performance when administered for a longer duration (&amp;gt; 15 days).

Long-term results of isolated transmyocardial laser revascularization in combination with the intramyocardial autologous bone marrow stem cells injection.

To evaluate the long-term results of TMLR using a CO2 laser in combination with intramyocardial injection of ABMSC as an isolated procedure in patients with the end-stage coronary artery disease, the study included 20 patients (90% male), with a mean age of 58.4 ± 8.7 years. To assess the long-term results, patients were examined in a hospital. The Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the Seattle Angina Questionnaire (SAQ) were used. The evolution of laboratory and instrumental indices, as well as medical therapy, was assessed. The end points of the study were death, acute myocardial infarction (AMI), repeated myocardial revascularization, recurrent hospitalizations due to coronary artery disease, and stroke. The changes in angina functional class were also evaluated. The median of follow-up period was 54 (36; 83) months, that is, 4.5 years. The analysis of the evolution of echocardiographic data showed the absence of statistically significant changes in the following parameters: left ventricular end-diastolic diameter (EDD) (p = 0.967), end-systolic diameter (ESD) (p = 0.204), end-diastolic volume (EDV) (p = 0.852), end-systolic volume (ESV) (p = 0.125), and left ventricular ejection fraction (LVEF) (p = 0.120). The patients continued to regularly take the main groups of medications. Nitrate consumption was significantly reduced (p < 0.001). Significant positive dynamics were observed in the changes in angina functional class. At the baseline, all patients had angina III FC, in the long term, 3 patients had II FC, 11 patients had I FC, and 6 patients had no angina. Clinical outcomes (mortality, recurrent myocardial infarction, stroke) were absent during the follow-up period. There were two cases of repeated myocardial revascularization. Regression analysis revealed that SYNTAX score was associated with the clinical outcome "repeated revascularization." TMLR in combination with intramyocardial injection of ABMSC is a safe method to achieve a statistically significant antianginal effect and reduce the need for "nitrates," which in turn improves the quality of life and reduces the frequency of hospitalizations due to coronary artery disease. These results can be achieved with strict adherence to the certain indications for the intervention.

A novel application of hematite precipitation for high effective separation of Fe from Nd-Fe-B scrap

Rare earths, e.g. neodymium (Nd), praseodymium (Pr) and dysprosium (Dy), are abundant in the rare earth sintered magnet scrap (Nd-Fe-B scrap), but their recycling is tedious and costly due to the high content of impurity Fe. Herein, a novel approach was developed to effectively recycle rare earths from the scrap via an integrated acid dissolution and hematite precipitation method. The scrap contained 63.4% Fe, 21.6% Nd, 8.1% Pr and 3.9% Dy. It was dissolved in nitric, hydrochloric and sulfuric acids, separately. Nearly all impurity Fe in the scrap was converted to Fe3+ in nitric acid but was converted to Fe2+ in hydrochloric and sulfuric acids. After hydrothermal treatment, the rare earths in the three acids were almost unchanged. From nitric acid, 77.6% of total Fe was removed, but total Fe was not from the hydrochloric and sulfuric acids. By adding glucose, the removal of total Fe was further increased to 99.7% in nitric acid, and 97% of rare earths remained. The major mechanism underlying total Fe removal in nitric acid was the hydrolysis of Fe3+ into hematite, which was promoted by the consumption of nitrate during glucose oxidation. This method effectively recycled rare metals from the waste Nd-Fe-B scrap and showed great potential for industrial application.

Effective enrichment of Zn from smelting wastewater via an integrated Fe coagulation and hematite precipitation method

Coagulation is commonly applied to treat Zn-bearing wastewater from smelting industries (smelting wastewater), and thus the Zn-bearing sludge was considerably produced, which should be solidified before safety disposal. Herein, we demonstrated a novel approach to recycle Zn effectively from smelting wastewater via an integrated Fe coagulation and hematite precipitation method. First, smelting wastewater was coagulated by adding ferric chloride to generate Fe/Zn-bearing sludge (sludge for short). Secondly, the sludge was dissolved to generate an acid solution containing 2.2 g/L of Zn and 39.2 g/L of Fe. Thirdly, the Fe/Zn-bearing solution was hydrothermally treated, and 89% of Fe was eliminated to highly purified hematite block, whereas the percentage of Zn lost was below 1.1%. Finally, the hematite precipitates were collected, and the supernatant was hydrothermally treated again with the addition of glucose. When the molar ratio of glucose to Fe in the supernatant was 1.5, over 99.5% of Fe was precipitated in hematite nanoparticles with a diameter of 10–100 nm, and the residual Fe was 21.5 mg/L. The loss of Zn was below 0.4%, and the residual Zn in the solution was 2169 mg/L, 290 times of that in the smelting wastewater. The major mechanism for Fe removal was the hydrolysis of ferric nitrate into hematite, which was promoted by nitrate consumption in glucose oxidation. This paper is the first report of an environment-friendly method for enriching Zn without generating any waste.

Distinct nitrogen cycling and steep chemical gradients in Trichodesmium colonies

Trichodesmium is an important dinitrogen (N2)-fixing cyanobacterium in marine ecosystems. Recent nucleic acid analyses indicate that Trichodesmium colonies with their diverse epibionts support various nitrogen (N) transformations beyond N2 fixation. However, rates of these transformations and concentration gradients of N compounds in Trichodesmium colonies remain largely unresolved. We combined isotope-tracer incubations, micro-profiling and numeric modelling to explore carbon fixation, N cycling processes as well as oxygen, ammonium and nitrate concentration gradients in individual field-sampled Trichodesmium colonies. Colonies were net-autotrophic, with carbon and N2 fixation occurring mostly during the day. Ten percent of the fixed N was released as ammonium after 12-h incubations. Nitrification was not detectable but nitrate consumption was high when nitrate was added. The consumed nitrate was partly reduced to ammonium, while denitrification was insignificant. Thus, the potential N transformation network was characterised by fixed N gain and recycling processes rather than denitrification. Oxygen concentrations within colonies were ~60–200% air-saturation. Moreover, our modelling predicted steep concentration gradients, with up to 6-fold higher ammonium concentrations, and nitrate depletion in the colony centre compared to the ambient seawater. These gradients created a chemically heterogeneous microenvironment, presumably facilitating diverse microbial metabolisms in millimetre-sized Trichodesmium colonies.

Knowledge and beliefs about dietary inorganic nitrate among UK-based nutrition professionals: development and application of the KINDS online questionnaire

ObjectivesTo examine knowledge and beliefs about the biological roles of dietary inorganic nitrate in UK-based nutrition professionals, and to explore potential differences by participants’ education level.SettingAn online questionnaire was administered...

Vertical stratification and stability of biogeochemical processes in the deep saline waters of Lake Vanda, Antarctica

AbstractLake Vanda is a permanently ice‐covered lake in the McMurdo Dry Valleys of Antarctica. Its bottom waters remain stratified year‐round because of a strong salinity‐driven density gradient. We have assessed spatial patterns in and relationships between major biogeochemical processes in the water column of Lake Vanda. Samples were collected in the austral summers of 2008 and 2011 to measure concentrations of metabolites associated with a suite of biogeochemical processes across the deep salinity gradient. The shapes of the resulting geochemical profiles were consistent between 2008 and 2011. Metabolite production and consumption rates were estimated using a reactive transport model based on the assumption that vertical diffusion was the only active physical transport process. We validated this model for nitrification by using stable isotope incubations to show that this process was only active at depths predicted by the model. No nitrification activity was observed at 68 m depth in spite of overlapping oxygen and ammonium gradients. We attribute this lack of activity to the competitive inhibition of ammonia monooxygenase by methane. Net nitrous oxide and nitrate consumption were observed in the oxic water column, providing evidence of aerobic denitrification. The depth of maximum net oxygen production did not coincide with the deep chlorophyll maxima (at 59.3, 63, and 68.2 m) measured in the same profile. Finally, the integrated sulfide oxidation rate was high compared with other oxidation processes, indicating that sulfide was an important electron donor for the water column microbial community.