A Keggin Al13 -Montmorillonite Modified Separator Retards the Polysulfide Shuttling and Accelerates Li-Ion Transfer in Li-S Batteries.

The commercialization of Li-S batteries as a promising energy system is terribly impeded by the issues of the shuttle effect and Li dendrite. Keggin Al13 -pillared montmorillonite (AlMMT), used as the modified film of the separator together with super-P and poly (vinylidene fluoride) (PVDF), has a good chemical affinity to lithium polysulfide (LiPS) to retard the polysulfide shuttling, excellent electrolyte wettability, and a stable structure, which can improve the rate capability and cycling stability of Li-S batteries. Density function theory (DFT) calculations reveal the strong adsorption ability of AlMMT for LiPS. Consequently, the modified film allows Li-S batteries to reach 902 mAh g-1 at 0.2C after 200 cycles and 625 mAh g-1 at 1C after 1000 cycles. More importantly, a high reversible areal capacity of 4.04 mAh cm-2 can be realized under a high sulfur loading of 6.10 mg cm-2 . Combining the merits of rich resources of montmorillonite, prominent performance, simple operation and cost-effectiveness together, this work exploits a new route for viable Li-S batteries for applications.

Investigation of fibrous cap stresses on vulnerable plaques leading to heart attacks.

Rupture-prone plaques in the coronary arteries, called ``vulnerable plaques'', are recognized as the key factor in acute myocardial infarction. Vulnerable plaques have a thin fibrous cap over a large fatty core and are highly susceptible to rupture. In general, this type of plaque rupture is mainly associated with stress concentrated on the fibrous cap. Fibrous cap stresses are counted among the most important factors in the plaque rupture process and must be taken into consideration when assessing the plaque vulnerability leading to heart attacks. The objective of this paper was to investigate the effects of nitinol stent deployment on the morphological changes of vulnerable plaques and then to propose a new stent design concept for effectively reducing fibrous cap stresses and the associated rupture risk. The deployment of a self-expanding nitinol stent was modeled, and the resulting stress distribution on the fibrous cap was investigated. The fibrous cap stresses were more uniformly distributed and the maximum stress was reduced by 13% when the crown number of the stent was increased. This study demonstrates an excellent approach to stent design that could effectively reduce the risk of a vulnerable plaque rupturing and causing a heart attack.

Investigation of fibrous cap stresses on vulnerable plaques leading to heart attacks.

Rupture-prone plaques in the coronary arteries, called ``vulnerable plaques'', are recognized as the key factor in acute myocardial infarction. Vulnerable plaques have a thin fibrous cap over a large fatty core and are highly susceptible to rupture. In general, this type of plaque rupture is mainly associated with stress concentrated on the fibrous cap. Fibrous cap stresses are counted among the most important factors in the plaque rupture process and must be taken into consideration when assessing the plaque vulnerability leading to heart attacks. The objective of this paper was to investigate the effects of nitinol stent deployment on the morphological changes of vulnerable plaques and then to propose a new stent design concept for effectively reducing fibrous cap stresses and the associated rupture risk. The deployment of a self-expanding nitinol stent was modeled, and the resulting stress distribution on the fibrous cap was investigated. The fibrous cap stresses were more uniformly distributed and the maximum stress was reduced by 13% when the crown number of the stent was increased. This study demonstrates an excellent approach to stent design that could effectively reduce the risk of a vulnerable plaque rupturing and causing a heart attack.