Vitamin E Supplementation and Cardiovascular Events in High-Risk Patients

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2018RG000615

Aerosol Mixing State: Measurements, Modeling, and Impacts

Atmospheric Aerosol Chemistry: Spectroscopic and Microscopic Advances

Abstract. Mineral dust aerosols often observed over California in winter and spring, associated with long-range transport from Asia and the Sahara, have been linked to enhanced precipitation based on observations. Local anthropogenic pollution, on the other hand, was shown in previous observational and modeling studies to reduce precipitation. Here we incorporate recent developments in ice nucleation parameterizations to link aerosols with ice crystal formation in a spectral-bin cloud microphysical model coupled with the Weather Research and Forecasting (WRF) model in order to examine the relative and combined impacts of dust and local pollution particles on cloud properties and precipitation type and intensity. Simulations are carried out for two cloud cases (from the CalWater 2011 field campaign) with contrasting meteorology and cloud dynamics that occurred on 16 February (FEB16) and 2 March (MAR02). In both cases, observations show the presence of dust and biological particles in a relative pristine environment. The simulated cloud microphysical properties and precipitation show reasonable agreement with aircraft and surface measurements. Model sensitivity experiments indicate that in the pristine environment, the dust and biological aerosol layers increase the accumulated precipitation by 10–20% from the Central Valley to the Sierra Nevada for both FEB16 and MAR02 due to a ~40% increase in snow formation, validating the observational hypothesis. Model results show that local pollution increases precipitation over the windward slope of the mountains by a few percent due to increased snow formation when dust is present, but reduces precipitation by 5–8% if dust is removed on FEB16. The effects of local pollution on cloud microphysics and precipitation strongly depend on meteorology, including cloud dynamics and the strength of the Sierra Barrier Jet. This study further underscores the importance of the interactions between local pollution, dust, and environmental conditions for assessing aerosol effects on cold-season precipitation in California.

Aerosol Impacts on California Winter Clouds and Precipitation during CalWater 2011: Local Pollution versus Long-Range Transported Dust

Atmospheric aerosol acidity impacts key multiphase processes, such as acid-catalyzed reactions leading to secondary organic aerosol formation, which impact climate and human health. However, traditional indirect methods of estimating aerosol pH often disagree with thermodynamic model predictions, resulting in aerosol acidity still being poorly understood in the atmosphere. Herein, a recently developed method coupling Raman microspectroscopy with extended Debye–Huckel activity calculations to directly determine the acidity of individual particles (1−15 μm projected area diameter, average 6 μm) was applied to a range of atmospherically relevant inorganic and organic acid–base equilibria systems (HNO3/NO3–, HC2O4–/C2O42–, CH3COOH/CH3COO–, and HCO3–/CO32–) covering a broad pH range (−1 to 10), as well as an inorganic–organic mixture (sulfate-oxalate). Given the ionic strength of the inorganic solutions, the H+ activity, γ(H+), yielded lower values (0.68–0.75) than the organic and mixed systems (0.72–0.80). A ...

Spectroscopic Determination of Aerosol pH from Acid–Base Equilibria in Inorganic, Organic, and Mixed Systems

The authors evaluated, in a community-based open-label trial, the effectiveness and safety of perindopril in 13,220 US hypertensive patients and studied how physicians adhere to hypertension treatment guidelines. Patients received perindopril 4 mg q.d. for 6 weeks. Based on physicians' perception of blood pressure response, the patient was either maintained on 4 mg or the dose was increased to 8 mg for an additional 6 weeks. From baseline to week 12, the mean sitting blood pressure significantly declined from 156.9/94.5 mm Hg to 139.2/84.0 mm Hg. Further dose titration resulted in a clinically significant reduction in blood pressure in all patients with inadequate response on 4 mg at week 6. Blood pressure control (<140/<90 mm Hg) was achieved at 12 weeks in 48.8% patients. The subpopulation analyses demonstrated that perindopril monotherapy was effective in both men and women, in patients of all ethnicities, and in patients <65 and ≤65 years of age. Perindopril was safe and well tolerated in all hypertensive subgroups including high-risk patients. Physicians were more attuned to controlling diastolic than systolic blood pressure, and their adherence to the treatment guidelines was found to be not optimal.

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Antihypertensive Utility of Perindopril in a Large, General Practice‐Based Clinical Trial

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2015JD024700

Changes in precipitating snow chemistry with location and elevation in the California Sierra Nevada

Several classes of antihypertensive agents have been shown to reduce cardiovascular morbidity and mortality in the high-risk hypertensive population, however, large hypertension trials have yet to demonstrate significant differences between treatments. The question that remains to be answered is ‐ do the different mechanisms of action of the antihypertensive drugs possess different cardiovascular protective properties beyond blood pressure lowering? The Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial was designed to test the hypothesis that for the same degree of blood pressure (BP) lowering, the angiotensin receptor blocker (ARB), valsartan, would reduce cardiac morbidity and mortality more than the calcium channel blocker, amlodipine, in highrisk hypertensive patients. The majority of enrolled patients were previously on antihypertensive therapy and were directly rolled over to randomized therapy consisting of a gradual up-titration of valsartan or amlodipine, with the addition of diuretics to achieve target BP. The late-breaking results of VALUE, as well as the clinical implications of the results, are the subject of this Cardiology Scientific Update.

The Importance of Prompt Blood Pressure Control to Target in High Risk Hypertensive Patients: The Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial

Michael Weber

Papers

Antihypertensive Utility of Perindopril in a Large, General Practice‐Based Clinical Trial

Changes in precipitating snow chemistry with location and elevation in the California Sierra Nevada

The Importance of Prompt Blood Pressure Control to Target in High Risk Hypertensive Patients: The Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial