No abstract

4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), a major active metabolite of bisphenol A (BPA), is generated in the mammalian liver. Some studies have suggested that MBP exerts greater toxicity than BPA. However, the mechanism underlying MBP-induced pancreatic β-cell cytotoxicity remains largely unclear. This study demonstrated the cytotoxicity of MBP in pancreatic β-cells and elucidated the cellular mechanism involved in MBP-induced β-cell death. Our results showed that MBP exposure significantly reduced cell viability, caused insulin secretion dysfunction, and induced apoptotic events including increased caspase-3 activity and the expression of active forms of caspase-3/-7/-9 and PARP protein. In addition, MBP triggered endoplasmic reticulum (ER) stress, as indicated by the upregulation of GRP 78, CHOP, and cleaved caspase-12 proteins. Pretreatment with 4-phenylbutyric acid (4-PBA; a pharmacological inhibitor of ER stress) markedly reversed MBP-induced ER stress and apoptosis-related signals. Furthermore, exposure to MBP significantly induced the protein phosphorylation of JNK and AMP-activated protein kinase (AMPK)α. Pretreatment of β-cells with pharmacological inhibitors for JNK (SP600125) and AMPK (compound C), respectively, effectively abrogated the MBP-induced apoptosis-related signals. Both JNK and AMPK inhibitors also suppressed the MBP-induced activation of JNK and AMPKα and of each other. In conclusion, these findings suggest that MBP exposure exerts cytotoxicity on β-cells via the interdependent activation of JNK and AMPKα, which regulates the downstream apoptotic signaling pathway.

No abstract

Based on novel design of moveable magnet between two mutually inimical magnetic forces without strict fabrication, for the first time, we demonstrate successfully a producible power generator with significant efficiency enhancement at broadband frequency range of 1 Hz ~ 1 kHz, 3D-colis stackability for output voltage improvement, and recycling vibration energy on automobile simultaneously. Even though the vibration frequency is as low as 1 Hz, two orders-of-magnitude improvements in normalized power (the ratio of power to product of external force and coil turns) provided from previous reports can be obtained. Further, comparing our device with maturely accelerometer chip (MMA7361) indicates that proposed strategies benefit harvesting vibration energy on driving automobile indeed. This vibrated power generator inturn provides high potential for applications, such as human motion (1 Hz ~ 2 Hz), sporting (5 Hz ~ 10 Hz), and automotive (10 Hz ~ 1 kHz) etc..

In this study we demonstrated that the improvement of detection capability of cadmium sulfide (CdS) photoconductors in the ultraviolet (UV) regime is much larger than that in the visible regime, suggesting that the deep UV laser treated CdS devices are very suitable for low-light detection in the UV regime. In addition, we determined that a nanocrystallized CdS photoconductor can behave as a picowatt-sensitive detector in the UV regime after ultra-shallow-region crystallization of the CdS film upon a single shot from a KrF laser. The strategy proposed herein appears to have great potential for application in the development of CdS photoconductors for picowatt-level detection of UV light with low power consumption.