Cell-based Biological Pacemakers: Progress and Problems

The number of permanent pacemaker implantations has been increasing due to the aging of populations worldwide and the increase in the numbers of patients with heart diseases. Commercially available mechanical pacemakers are very useful but still have some problems including short battery life, a risk of infection, the absence of physiological autonomic responsiveness, metal allergy, and electronic interference. A biological pacemaker may resolve these problems and regenerate the cardiac pacemaker. Cell-based therapy and gene therapy have been addressed with the goal of solving the challenges of biological pacemaker. However, the clinical application of a biological pacemaker has not yet been realized. Here we discuss the types of cells that can be used for a biological pacemaker and the problems that remain regarding the clinical applications of cell-based therapy

Molecular Mechanisms of Cardiac Amyloidosis

Cardiac involvement has a profound effect on the prognosis of patients with systemic amyloidosis. Therapeutic methods for suppressing the production of causative proteins have been developed for ATTR amyloidosis and AL amyloidosis, which show cardiac involvement, and the prognosis has been improved. However, a method for removing deposited amyloid has not been established. Methods for reducing cytotoxicity caused by amyloid deposition and amyloid precursor protein to protect cardiovascular cells are also needed. In this review, we outline the molecular mechanisms and treatments of cardiac amyloidosis

Effects of Eicosapentaenoic Acid on Arterial Calcification

Arterial calcification is a hallmark of advanced atherosclerosis and predicts cardiovascular events. However, there is no clinically accepted therapy that prevents progression of arterial calcification. HMG-CoA reductase inhibitors, statins, lower low-density lipoprotein-cholesterol and reduce cardiovascular events, but coronary artery calcification is actually promoted by statins. The addition of eicosapentaenoic acid (EPA) to statins further reduced cardiovascular events in clinical trials, JELIS and REDUCE-IT. Additionally, we found that EPA significantly suppressed arterial calcification in vitro and in vivo via suppression of inflammatory responses, oxidative stress and Wnt signaling. However, so far there is a lack of evidence showing the effect of EPA on arterial calcification in a clinical situation. We reviewed the molecular mechanisms of the inhibitory effect of EPA on arterial calcification and the results of some clinical trials

Ambegaokar-Baratoff relations of Josephson critical current in heterojunctions with multi-gap superconductors

An extension of the Ambegaokar-Baratoff relation to a superconductor-insulator-superconductor (SIS) Josephson junction with multiple tunneling channels is derived. Appling the resultant relation to a SIS Josephson junction formed by an iron-based (five-band) and a single-band Bardeen-Cooper-Schrieffer (BCS) type superconductors, a theoretical bound of the Josephson critical current ($I_{\rm c}$) multiplied by the resistance of the junction ($R_{\rm n}$) is given. We reveal that such a bound is useful for identifying the pairing symmetry of iron-pnictide superconductors. One finds that if a measured value of $I_{\rm c}R_{\rm n}$ is smaller than the bound then the symmetry is $\pm s$-wave, and otherwise $s$-wave without any sign changes. In addition, we stress that temperature dependence of $I_{\rm c}R_{\rm n}$ is sensitive to the difference of the gap functions from the BCS type gap formula in the above heterojunction.Comment: 7 pages, 6 figure

A memory-based programmable logic device using look-up table cascade with synchronous static random access memories

A large-scale memory-technology-based programmable logic device (PLD) using LUT (Look-Up Table) cascade is developed in 0.35um Standard CMOS logic process. Eight 64K-bit synchronous SRAMs are connected to form an LUT cascade with a few additional circuits. The features of the LUT cascade include: 1) flexible cascade connection structure, 2) multi-phase pseudo-asynchronous operations with synchronous SRAM cores, 3) LUT-bypass redundancy. This chip operates at 33MHz in 8-LUT cascades with 122mW. Benchmark results show that it achieves a comparable performance to FPGAs