In this work, it is analyzed the effect of the partial substitution of Fe by Ni in a BaFeO
3
perovskite to be used as the catalyst for NO
x
-assisted diesel soot oxidation. A series of BaFe
1−x
Ni
x
...O
3
(x = 0, 0.2, 0.4 and 0.8) catalysts have been synthesized by using the sol–gel method. The catalysts have been characterized by ICP-OES, XRD, XPS, O
2
-TPD, H
2
-TPR- and TEM. The catalytic activity for NO to NO
2
oxidation and NO
x
-assisted diesel soot oxidation have been determined by Temperature Programmed Reaction experiments (NO
x
-TPR and Soot-NO
x
-TPR, respectively) and by isothermal reaction at 450 °C. Ni seems not to be inserted in the BaFeO
3
perovskite and, instead of that, BaNiO
3
perovskite and NiO are detected on the surface of the perovskite BaFeO
3
. XPS data reveal the coexistence of Fe(III) and Fe(IV) on the catalyst’s surface (being Fe(III) the main oxidation state) and the presence of oxygen vacancies. All catalysts are active for NO oxidation to NO
2
, showing BaFeO
3
and BaFe
0.6
Ni
0.4
O
3
the best catalytic performance. BaFe
0.6
Ni
0.4
O
3
shows the highest proportion of nickel on surface and it combines the highest activity and stability for NO
x
-assisted diesel soot oxidation. Also, this catalyst presents the highest initial soot oxidation rate which minimizes the accumulation of unreacted soot during reaction.
Atlantic Meridional Overturning Circulation (AMOC) plays a major role in the climate system by modulating the depth and rate of oceanic heat storage. Some climate simulations suggest that reduced ...AMOC decreases bottom water ventilation and that the heat absorbed by the ocean starts to mix downwards, warming Atlantic intermediate waters. This has been corroborated for the western North Atlantic by benthic foraminifera geochemical records from periods of reduced AMOC during the last deglaciation. However, the deep‐water response remains poorly constrained, and the lack of direct paleotemperature reconstructions limits our understanding about the effects of reduced circulation on ocean heat uptake. We present a new reconstruction of bottom water temperatures from core GeoB9508‐5 (2,384 m water depth, 15°29.90°N/17°56.88°W) off the northwestern African Margin. Our paleotemperature record, based on Uvigerina spp. Mg/Ca, shows two episodes of intense transient deep water warming in times of decreasing overturning circulation, followed by long periods of heat uptake stagnation. First, during AMOC slowdown in the Heinrich stadial 1, when paleotemperatures of ∼2°C persisted for ∼5.4 Kyr coincident with the weakest stage of AMOC; and second in the Younger Dryas, when bottom water temperatures >4°C lasted ∼2.5 Kyr during a less intense AMOC decline. This suggests a stagnation of deep‐water heat uptake in the deep NE Atlantic possibly linked to a reduced downward advection of heat during times of a reduced AMOC, supporting the hypothesis that AMOC strength sets the depth of oceanic heat storage in the North Atlantic.
Plain Language Summary
Anthropogenic activity affects earth‐atmosphere energy balance enhancing climate change in the last decades. The ocean plays a key role in this balance, by taking up to 90% of the excess heat from the atmosphere and redistributing it globally though the Atlantic Meridional Overturning Circulation (AMOC). For the 21st century, a possible 34%–45% AMOC reduction has been hypothesized, raising concern on its effects on ocean heat uptake and climate change. To contribute to the understanding of these possible effects, we reconstructed bottom water temperatures changes for eastern North Atlantic deep waters over the last 46,000 years, including two periods with a significantly reduced AMOC: (a) Heinrich Stadial 1 (18,200–14,900 years ago) and (b) the Younger Dryas (12,800–11,700 years ago). Our results suggest that with a weak AMOC, Atlantic intermediate waters warm as ventilation decreases, at the same time this heat stops being transferred to the deep eastern North Atlantic for thousands of years. The implications of these processes for global warming still need to be investigated.
Key Points
Intense North Atlantic Deep‐Water (NADW) warming at the beginning of Heinrich Stadial 1 (HS1) and the Younger Dryas (YD)
With a weak Atlantic Meridional Overturning Circulation during HS1 and the YD deep water temperature remained stable in poorly ventilated bottom waters
Weaker HS1 and YD NADW formation, may reduce heat dissipation into the deep Atlantic
•Acute exposure to O3 induces lung function decrements and airway inflammation.•Fish oil supplements blunted O3 – induced lung function effects but not inflammation.•Protective effects of olive oil ...supplements were less pronounced than those of fish oil.•OO blunted blood pressure elevations induced by O3 exposure.•Beneficial oils have potential as public health interventions against air pollution.
Over one-third of the U.S. population is exposed to unsafe levels of ozone (O3). Dietary supplementation with fish oil (FO) or olive oil (OO) has shown protection against other air pollutants. This study evaluates potential cardiopulmonary benefits of FO or OO supplementation against acute O3 exposure in young healthy adults.
Forty-three participants (26 ± 4 years old; 47% female) were randomized to receive 3 g/day of FO, 3 g/day OO, or no supplementation (CTL) for 4 weeks prior to undergoing 2-hour exposures to filtered air and 300 ppb O3 with intermittent exercise on two consecutive days. Outcome measurements included spirometry, sputum neutrophil percentage, blood markers of inflammation, tissue injury and coagulation, vascular function, and heart rate variability. The effects of dietary supplementation and O3 on these outcomes were evaluated with linear mixed-effect models.
Compared with filtered air, O3 exposure decreased FVC, FEV1, and FEV1/FVC immediately post exposure regardless of supplementation status. Relative to that in the CTL group, the lung function response to O3 exposure in the FO group was blunted, as evidenced by O3-induced decreases in FEV1 (Normalized CTL −0.40 ± 0.34 L, Normalized FO −0.21 ± 0.27 L) and FEV1/FVC (Normalized CTL −4.67 ± 5.0 %, Normalized FO −1.4 ± 3.18 %) values that were on average 48% and 70% smaller, respectively. Inflammatory responses measured in the sputum immediately post O3 exposure were not different among the three supplementation groups. Systolic blood pressure elevations 20-h post O3 exposure were blunted by OO supplementation.
FO supplementation appears to offer protective effects against lung function decrements caused by acute O3 exposure in healthy adults.
Abstract Background and aims In Italy, the reimbursed use of incretin mimetics and incretin enhancers was subject to enrollment of patients into a web-based system recording the general demographic ...and clinical data of patients. We report the utilization data of glucagon-like peptide 1 (GLP1) receptor agonists and dipeptidylpeptidase-4 (DPP4) inhibitors in clinical practice as recorded by the Italian Medicines Agency (AIFA) Monitoring Registry. Methods and results From February 2008 to August 2010, 75,283 patients with type 2 diabetes were entered into the registry and treated with exenatide, sitagliptin, or vildagliptin. The treatment was administered to patients in a wide range of ages (≥75 years, n = 6125 cases), body mass index (BMI) (≥35 kg/m2 , n = 22,015), and metabolic control (HbA1c ≥ 11% ((96 mmol/mol), n = 3151). Overall, 1116 suspected adverse drug reactions were registered, including 12 cases of acute pancreatitis (six on exenatide). Hypoglycemic episodes mainly occurred in combination with sulfonylureas. Treatment discontinuation for the three drugs (logistic regression analysis) was negatively associated with the male gender and positively with baseline HbA1c , diabetes duration, and, limitedly to DPP-4 inhibitors, with BMI. Treatment discontinuation (including loss to follow-up, accounting for 21–26%) was frequent. Discontinuation for treatment failure occurred in 7.7% of cases (exenatide), 3.8% (sitagliptin), and 4.1% (vildagliptin), respectively, corresponding to 27–40% of all discontinuations, after excluding lost to follow-up. HbA1c decreased on average by 0.9–1.0% (9 mmol/mol). Body weight decreased by 3.5% with exenatide and by 1.0–1.5% with DPP-4 inhibitors. Conclusions In the real world of Italian diabetes centers, prescriptions of incretins have been made in many cases outside the regulatory limits. Nevertheless, when appropriately utilized, incretins may grant results at least in line with pivotal trials.
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