Our increasing dependence on lithium-ion batteries for energy storage calls for continual improvements in the performance of their positive electrodes, which have so far relied solely on cationic redox of transition-metal ions for driving the electrochemical reactions. Great hopes have recently been placed on the emergence of anionic redox—a transformational approach for designing positive electrodes as it leads to a near-doubling of capacity. But questions have been raised about the fundamental origins of anionic redox and whether its full potential can be realized in applications. In this Review, we discuss the underlying science that triggers a reversible and stable anionic redox activity. Furthermore, we highlight its practical limitations and outline possible approaches for improving such materials and designing new ones. We also summarize their chances for market implementation in the face of the competing nickel-based layered cathodes that are prevalent today. The discovery of anionic redox chemistry in Li-rich cathode materials provides much hope for enhancing battery performance. Tarascon and Assat analyse the underlying science behind anionic redox and discuss its practical limitations as well as the routes to overcome the application barriers.

https://hal.archives-ouvertes.fr/hal-03315776/document

Fundamental understanding and practical challenges of anionic redox activity in Li-ion batteries

A Randomized Comparison of Pulmonary Vein Isolation With Versus Without Concomitant Renal Artery Denervation in Patients With Refractory Symptomatic Atrial Fibrillation and Resistant Hypertension

Hypertension is considered to be the most important risk factor in the development of cardiovascular disease. An increasing body of evidence suggests that oxidative stress, which results in an excessive generation of reactive oxygen species (ROS), has a key role in the pathogenesis of hypertension. The modulation of the vasomotor system involves ROS as mediators of vasoconstriction induced by angiotensin II, endothelin-1 and urotensin-II, among others. The bioavailability of nitric oxide (NO), which is a major vasodilator, is highly dependent on the redox status. Under physiological conditions, low concentrations of intracellular ROS have an important role in the normal redox signaling maintaining vascular function and integrity. However, under pathophysiological conditions, increased levels of ROS contribute to vascular dysfunction and remodeling through oxidative damage. In human hypertension, an increase in the production of superoxide anions and hydrogen peroxide, a decrease in NO synthesis and a reduction in antioxidant bioavailability have been observed. In turn, antioxidants are reducing agents that can neutralize these oxidative and otherwise damaging biomolecules. The use of antioxidant vitamins, such as vitamins C and E, has gained considerable interest as protecting agents against vascular endothelial damage. Available data support the role of these vitamins as effective antioxidants that can counteract ROS effects. This review discusses the mechanisms involved in ROS generation, the role of oxidative stress in the pathogenesis of vascular damage in hypertension, and the possible therapeutic strategies that could prevent or treat this disorder.

/pdf/the-role-of-oxidative-stress-in-the-pathophysiology-of-55p6ryrbni.pdf

The role of oxidative stress in the pathophysiology of hypertension

Expert consensus document from the European Society of Cardiology on catheter-based renal

Aim The aim of this study was to determine long-term results of renal artery denervation for treatment of treatment-resistant hypertension in the SYMPLICITY HTN-2 study.

Methods SYMPLICITY HTN-2 randomized 106 subjects with treatment-resistant hypertension to renal denervation or medical therapy alone. At 6 months, 37 control subjects crossed over to renal denervation. Office blood pressure measurements, antihypertensive medication use, and safety events were followed every 6 months through 3 years.

Results Follow-up was available at 36 months in 40 of 52 subjects in the initial renal denervation group and at 30 months in 30 of 37 subjects who crossed over and received renal denervation at 6 months. Baseline blood pressure was 184 ± 19/99 ± 16 mmHg in all treated subjects. At 30-month post-procedure, systolic blood pressure decreased 34 mmHg (95% CI: −40, −27, P < 0.01) and diastolic blood pressure decreased 13 mmHg (95% CI: −16, −10, P < 0.01). The systolic and diastolic blood pressure reduction at 36 months for the initial renal denervation group was −33 mmHg (95% CI: −40, −25, P < 0.01) and −14 mmHg (95% CI: −17, −10, P < 0.01), respectively. Procedural complications included one haematoma, and one renal artery dissection before energy delivery that was treated successfully. Later complications included two cases of acute renal failure, which fully resolved, 15 hypertensive events requiring hospitalization, and three deaths.

Conclusion Renal denervation resulted in sustained lowering of blood pressure at 3 years in a selected population of subjects with severe, treatment-resistant hypertension without serious safety concerns.

Clinical trial registration NCT00888433.

Catheter-based renal denervation for treatment of patients with treatment-resistant hypertension: 36 month results from the SYMPLICITY HTN-2 randomized clinical trial.

The fiber gyro, utilizing the Sagnac effect and under development since the early 1980s, has reached production status as a low-cost rotation rate sensor for various high volume applications, satisfied by drift rates of 10°/h and more. Lower drift rates will be offered by series production fiber gyros within the next two years. Principles, technologies and performance data of SEL fiber gyros are discussed, as well as some principal applications. The paper introduces also the concept of a new class of inertial fiber motion sensors based upon the Kennedy-Thorndike interferometer. Such sensors for inertial velocity can enable inertial strapdown navigation without accelerometers.

Manfred Bohm

Papers

Achievements And Perspectives Of Fiber Gyros