STRETCHING EXERCISE TRAINING AND EDUCATION (SETE) PROGRAM FOR HOUSEKEEPING STAFF AT THE QUEEN’S MEDICAL CENTER

D.N.P.D.N.P. Thesis. University of Hawaiʻi at Mānoa 201

Asset-Based Policy in South Korea

Asset-Based Policy in South Kore

\u3ci\u3eR\u3c/i\u3e-Curve Behavior of \u3ci\u3eIn Situ\u3c/i\u3e Toughened alpha-SiAlON Ceramics

R-curves of single-phase Y- and Ca-containing α-SiAlON ceramics have been measured. They range from flat ones for fine-grain ceramics to pronounced rising ones when large elongated grains are present. The highest toughness measured reached 11.5 MPa∙m1/2 over a crack extension of about 1000 μm

Effect of Seeding on the Microstructure and Mechanical Properties of alpha-SiAlON: I, Y-SiAlON

The effect of seeding on the microstructure and mechanical properties of single-phase Y-α-SiAlON ceramics with elongated grains has been studied. Seeds of the intended α-SiAlON compositions but with different size, shape, and number of grains have been compared for their effects. The microstructure, resistance (R-curve) behavior, and Weibull modulus are strongly correlated to the number density of the seeds. The highest fracture toughness reached is ~12 MPa∙m1/2 and can be obtained with as little as 1% seeding. The thermodynamic stability of seeds has been examined and is attributed to their chemical composition

Synthesis of alpha-SiAlON Seed Crystals

Single-phase seed crystals of Ca- and Y-α-SiAlONs have been synthesized for tailoring microstructure of α-SiAlON ceramics. The influence of composition, sintering temperature, and nitrogen pressure on the size and morphology of seeds has been explored. Guidelines for α-SiAlON seed preparation and morphology control are provided

Prolonged Activation of ERK Contributes to the Photorejuvenation Effect in Photodynamic Therapy in Human Dermal Fibroblasts

Photodynamic therapy (PDT) is known to be effective in the photorejuvenation of photoaged skin. However, the molecular mechanisms of rejuvenation by PDT remain elusive. In this study, we aimed to understand the molecular events occurring during the photorejuvenation after PDT in dermal fibroblasts in vitro. First, we found that PDT conditions resulted in an increased fibroblast proliferation and motility in vitro. Under this condition, cells had increased intracellular reactive oxygen species (ROS) production. Importantly, PDT induced a prolonged activation of extracellular signal–regulated kinase (ERK) with a corresponding increase in matrix metalloproteinase (MMP)-3 and collagen type Iα messenger RNA and protein. Moreover, inhibition of PDT-induced ERK activation significantly suppressed fibroblast proliferation and expression of MMP-3 and collagen type Iα following PDT. In addition, NAC (an antioxidant) inhibited PDT-induced fibroblast proliferation and ERK activation indicating that prolonged ERK activation and intracellular ROS contribute to the proliferation of fibroblasts and the dermal remodeling process for skin rejuvenation. We also identified increased collagen volume and decreased elastotic materials that are used as markers of photoaging in human skin samples using histochemical studies. Results from this study suggest that intracellular ROS stimulated by PDT in dermal fibroblasts lead to prolonged activation of ERK and, eventually, fibroblast proliferation and activation. Our data thus reveal a molecular mechanism underlying the skin rejuvenation effect of PDT