J-wave syndromes: Brugada and early repolarization syndromes.

A prominent J wave is encountered in a number of life-threatening cardiac arrhythmia syndromes, including the Brugada syndrome and early repolarization syndromes. Brugada syndrome and early repolarization syndromes differ with respect to the magnitude and lead location of abnormal J waves and are thought to represent a continuous spectrum of phenotypic expression termed J-wave syndromes. Despite two decades of intensive research, risk stratification and the approach to therapy of these 2 inherited cardiac arrhythmia syndromes are still undergoing rapid evolution. Our objective in this review is to provide an integrated synopsis of the clinical characteristics, risk stratifiers, and molecular, ionic, cellular, and genetic mechanisms underlying these 2 fascinating syndromes that have captured the interest and attention of the cardiology community in recent years

Dynamic investment, debt structure and debt overhang

We study the impact of the optimal debt and priority structure on the intertwined corporate financing and investment decisions in a dynamic trade-off model, where the firm simultaneously uses bank and market debt for project financing. Private bank debt is renegotiable during financial distress, thus it avoids inefficient and costly bankruptcy losses should the renegotiation be successful. Our model shows: (i) Shareholders' bargaining power, renegotiation friction, growth potential, and bankruptcy costs limits bank debt capacity; (ii) The substitution effect between bank and market debt dominates in most cases; (iii) Bank debt issuance reduces the bankruptcy risk and speeds firm investment, which mitigates the debt overhand effect; (iv) Debt priority structure has a monotonic positive effect on firms' optimal capital structure, the net benefit of mixed debt financing, and firm valuation, the effect of which is much stronger for weaker shareholders, therefore, it would be optimal to place bank debt as senior for firm value maximization; (v) The benefit of mixed debt financing is significant (a firm valuation boost between 5%- 10% ) compared to either the bank debt exclusive or market debt exclusive debt structure

Preliminary Study Of Dicalcium Phosphate Dihydrate Coated 45S5 Bioglass Granule

In this study, dicalcium phosphate dihydrate (DCPD) which has higher solubility is being coated on the 45S5 bioglass granule surface to improve the bone regeneration rate. The objectives of this preliminary study are to determine the effect of acidic calcium phosphate solution concentration in fabricating dicalcium phosphate diphosphate (DCPD) coated 45S5 bioglass granules and its effect of exposure duration when soaking in acidic calcium phosphate solution. 45S5 bioglass is first fabricated by using melt-quench method and the fabricated 45S5 bioglass is verified through morphology observation, elemental analysis and compositional analysis. To achieve the first objective, 45S5 bioglass granules was exposed to acidic calcium phosphate solution with different concentration (25 mmol/L, 50 mmol/L, 75 mmol/L, 100 mmol/L) for 2 hours to form a DCPD layer on the 45S5 bioglass granule surface through dissolution-precipitation reaction. While for the second objectives, the concentration of acidic calcium phosphate was fixed at 100mmol/L and 45S5 bioglass granules were soaked in the solution for 2 and 6 hours, respectively. The DCPD-coated 45S5 bioglass are then characterized with Scanning Electron Microscope (SEM), X-Ray Fluorescence Spectroscopy (XRF), X-ray Diffractometer (XRD) and pH analysis. The results showed that the amount of DCPD crystals precipitate on the 45S5 bioglass granule surface increased as the concentration of ACaP solution and exposed duration increased. In this study, even the DCPD is detected to be precipitated on the 45S5 bioglass granule surface, the results has shown that the DCPD precipitated is not fully covered the 45S5 bioglass granule surface and further study is required to understand the appropriate method to fully cover the 45S5 bioglass granules surface with DCPD