Data on the utilization of treatment modalities for ED in Taiwan in the era of PDE5 inhibitors.

Oral PDE5 inhibitors, intracavernosal injection and penile implants are mainstay treatments for ED. Data on their utilization reflect economic aspects of ED, but are underreported. We report utilization data and user characteristics for these modalities in Taiwan between 1999 and 2011. Sales data on PDE5 inhibitors-sildenafil citrate, tadalafil and vardenafil and on alprostadil were retrieved from International Market Services Health, and on penile implants from the local importing company for them. Users' clinical characteristics were derived from one institution. Between 1999 and 2011, sales of PDE5 inhibitors increased 5.9-fold, whereas those of alprostadil and penile implants remained stable. Over 90% of PDE5 inhibitors were purchased in pharmacies without a prescription. Between 1999 and 2011, the number of patients who received PDE5 inhibitors (n=4715) exceeded those who underwent penile injection (n=333) and penile implantation (n=108). The mean age of patients with ED who first received PDE5 inhibitors tended to decrease over consecutive years. Discontinuation of treatment with PDE5 inhibitors or intracavernosal injection reached 90% within 3 years of treatment initiation. Our data on the increasing market for PDE5 inhibitors and the trend for first use of PDE5 inhibitors at younger ages highlight the growing burden of ED and the acceptance of PDE5 inhibitors as the primary treatment for ED.

Testosterone replacement therapy can increase circulating endothelial progenitor cell number in men with late onset hypogonadism.

Circulating endothelial progenitor cells (EPCs) are bone marrow-derived cells required for endothelial repair. A low EPC number can be considered as an independent predictor of endothelial dysfunction and future cardiovascular events. Recent evidence shows that patients with hypogonadal symptoms without other confounding risk factors have a low number of circulating progenitor cells (PCs) and EPCs, thus highlighting the role of testosterone in the proliferation and differentiation of EPCs. Here, we investigate if testosterone replacement therapy (TRT) can increase circulating EPC number in men with late onset hypogonadism. Forty-six men (age range, 40-73 years; mean age, 58.3 years) with hypogonadal symptoms were recruited, and 29 men with serum total testosterone (TT) levels less than 350 ng/dL received TRT using transdermal testosterone gel (Androgel; 1% testosterone at 5 g/day) for 12 months. Circulating EPC numbers (per 100 000 monocytes) were calculated using flow cytometry. There was no significant association between serum TT levels and the number of circulating EPCs before TRT. Compared with the number of mean circulating EPCs at baseline (9.5 ± 6.2), the number was significantly higher after 3 months (16.6 ± 11.1, p = 0.027), 6 months (20.3 ± 15.3, p = 0.006) and 12 months (27.2 ± 15.5, p = 0.017) of TRT. Thus, we conclude that serum TT levels before TRT are not significantly associated with the number of circulating EPCs in men with late onset hypogonadism. However, TRT can increase the number of circulating EPCs, which implies the benefit of TRT on endothelial function in hypogonadal men.

Hybrid ferrohydrodynamic instability: coexisting peak and labyrinthine patterns.

We present an experimental study of a different pattern-forming instability occurring when a ferrofluid droplet is immersed in a thin layer of a nonmagnetic fluid, and subjected to a uniform perpendicular magnetic field. The formation of intriguing interfacial structures is observed, and the development of a hybrid-type ferrohydrodynamic instability is verified, where peak and labyrinthine ferrofluid patterns coexist and share a coupled dynamic evolution. Based on our experimental findings we have identified the occurrence of three well defined regimes for the evolution of the miscible Rosensweig peak in which it first grows rapidly, and then gradually decays, to ultimately reimmerse into the surrounding nonmagnetic solvent layer. This unique scenario for the rise and fall of the Rosensweig peak implies the simultaneous emergence of peculiar labyrinthine structures induced by an outward radial flow within the thin nonmagnetic layer. A variety of possible morphologies is revealed (labyrinth, broken tentaclelike fingers, etc.), which result from the interplay between magnetic, diffusive, and convective effects. These free surface flow labyrinthine structures are contrasted to alternative interfacial designs obtained when the experimental system is spatially confined.

Dynamic characteristics of long-wavelength quantum dot vertical-cavity surface-emitting lasers with light injection.

This investigation experimentally demonstrates the dynamic characteristics of quantum dot vertical-cavity surface-emitting lasers (QD VCSEL) without and with light injection. The QD VCSEL is fully doped structure on GaAs substrate and operates in the 1.3 mum optical communication wavelength. The eye diagram, frequency response, and intermodulation distortion are presented. We also demonstrate that the frequency response enhancement by light injection technique allows us to improve the performance of subcarrier multiplexed system.

Tunable slow light device using quantum dot semiconductor laser.

This investigation experimentally demonstrates a tunable slow light device using a quantum dot (QD) semiconductor laser. The QD semiconductor laser at 1.3 mum fabricated on a GaAs substrate is grown by molecular beam epitaxy. Tunable slow light can be achieved by adjusting the bias current and wavelength detuning. The slow light device operated under probe signal from 5 to 10 GHz is presented. Moreover, we also demonstrate that the tunable slow light device can be used in a subcarrier multiplexed system.

An accelerated learning algorithm for multilayer perceptron networks.

An accelerated learning algorithm (ABP-adaptive back propagation) is proposed for the supervised training of multilayer perceptron networks. The learning algorithm is inspired from the principle of "forced dynamics" for the total error functional. The algorithm updates the weights in the direction of steepest descent, but with a learning rate a specific function of the error and of the error gradient norm. This specific form of this function is chosen such as to accelerate convergence. Furthermore, ABP introduces no additional "tuning" parameters found in variants of the backpropagation algorithm. Simulation results indicate a superior convergence speed for analog problems only, as compared to other competing methods, as well as reduced sensitivity to algorithm step size parameter variations.