The ability to measure temperature in shock wave experiments has been a long-standing scientific challenge complicated by the short timescales involved (<1 microsecond) and the presence of nonthermal ...or external light sources that pollute measured radiances using optical pyrometry methods. In the current work, we present the first experimental data on cerium metal designed to measure the temperature on-Hugoniot from the low-pressure α phase well into the high-pressure liquid phase. Radiance data obtained in this work were used to determine the Hugoniot curves for solid (α-Ce) and liquid cerium by measuring the longitudinal stress and temperature simultaneously in the shocked state. These data were used to estimate the temperature for incipient shock melting and complete melting, and to further constrain a multiphase equation of state developed to describe the dynamic response of cerium at high pressures.
We report the measurement of the surface motion of a hemispherical copper shell driven by high explosives. This measurement was made using three 32 channel multiplexed photonic Doppler velocimetry ...(PDV) systems, in combination with a novel compound optical probe. Clearly visible are detailed features of the motion of the shell over time, enhanced by spatial correlation. Significant non-normal motion is apparent, and challenges in measuring such a geometry are discussed.
Pyrometry measurements on shock-heated metals are often performed through a transparent window acting as a shock anvil. Sapphire is an interesting anvil because of its rather high shock impedance but ...is also known to emit light when shocked above its Hugoniot elastic limit (HEL). To study its optical response, we have carried out experiments in which
c
-cut sapphire (i.e. crystal orientation
{
0
0
0
1
}
) was in contact with a metallic sample (tin or bismuth) or a lithium fluoride (LiF) window. The measurement of emitted light was performed using multi-wavelength pyrometry. In the experiments performed in the vicinity of the HEL of sapphire, the use of a LiF-sapphire compound window proved beneficial. Even though a significant amount of light is emitted over a large wavelength range by sapphire above its HEL, we notice that the signal rise is directly related to the volume of sapphire under shock-loading. Consequently, the light emitted by sapphire can be subtracted, allowing us to infer the true thermal radiation originating from the metal under study. A theoretical calculation of the expected pyrometry signals supports this point of view. These results give evidence that sapphire, despite its significant shock-induced optical emission above the HEL, can be used as a transparent anvil for quantitative pyrometry measurements at medium and high shock pressures.
Dietary sodium restriction has been shown to enhance the short-term response of blood pressure and albuminuria to angiotensin receptor blockers (ARBs). Whether this also enhances the long-term renal ...and cardiovascular protective effects of ARBs is unknown. Here we conducted a post-hoc analysis of the RENAAL and IDNT trials to test this in patients with type 2 diabetic nephropathy randomized to ARB or non-renin–angiotensin–aldosterone system (non-RAASi)–based antihypertensive therapy. Treatment effects on renal and cardiovascular outcomes were compared in subgroups based on dietary sodium intake during treatment, measured as the 24-h urinary sodium/creatinine ratio of 1177 patients with available 24-h urinary sodium measurements. ARB compared to non-RAASi–based therapy produced the greatest long-term effects on renal and cardiovascular events in the lowest tertile of sodium intake. Compared to non-RAASi, the trend in risk for renal events was significantly reduced by 43%, not changed, or increased by 37% for each tertile of increased sodium intake, respectively. The trend for cardiovascular events was significantly reduced by 37%, increased by 2% and 25%, respectively. Thus, treatment effects of ARB compared with non-RAASi–based therapy on renal and cardiovascular outcomes were greater in patients with type 2 diabetic nephropathy with lower than higher dietary sodium intake. This underscores the avoidance of excessive sodium intake, particularly in type 2 diabetic patients receiving ARB therapy.
Aims
The long-term cardioprotective effect of angiotensin receptor blockers (ARBs) is associated with the short-term lowering of its primary target blood pressure, but also with the lowering of ...albuminuria. Since the individual blood pressure and albuminuria response to an ARB varies between and within an individual, we tested whether the variability and discordance in systolic blood pressure (SBP) and albuminuria response to ARB therapy are associated with its long-term effect on cardiovascular outcomes.
Methods and results
The combined data of the RENAAL and IDNT trials were used. We first investigated the extent of variability and discordance in SBP and albuminuria response (baseline to 6 months). Subsequently, we assessed the combined impact of residual Month 6 SBP and albuminuria level with cardiovascular outcome. In ARB-treated patients, 421 patients (34.5%) either had a reduction in SBP but no reduction in albuminuria, or vice versa, indicating substantial discordance in response in these parameters. The initial reduction in SBP and albuminuria independently correlated with cardiovascular protection: HR per 5 mmHg SBP reduction 0.97 (95% CI 0.94-0.99) and HR per decrement log albuminuria 0.87 (95% CI 0.76-0.99). Across all SBP categories at Month 6, a progressively lower cardiovascular risk was observed with a lower albuminuria level. This was particularly evident in patients who reached the guideline recommended SBP target of ≤130 mmHg.
Conclusion
The SBP and albuminuria response to ARB therapy is variable and discordant. Therapies intervening in the renin-angiotensin-aldosterone system with the aim of improving cardiovascular outcomes may therefore require a dual approach targeting both blood pressure and albuminuria.
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