RBF and NSGA-II based EDM process parameters optimization with multiple constraints.

In this study, the radial basis function (RBF) which has good performance for nonlinear problem is introduced to approximate the implicit relationships between EDM parameters and performance responses for 304 steel. The fitting precision of RBF is compared with the second order polynomial response surface (PRS), support vector regression (SVR) and Kriging model (KRG) using the multiple correlation coefficient (R2) based cross validation error method. Then the RBF model is called to conduct multi-objective optimization using non-dominated sorting genetic algorithm II (NSGA-II) method.

Response of Chrysoperla nipponensis (Okamoto) (Neuroptera: Chrysopidae) Under Long and Short Photoperiods.

Photoperiod is an important factor influencing many biological processes including population dynamics of many insect species in temperate zones. To determine the population response of Chrysoperla nipponensis under altered conditions (high temperature and short photoperiod) and to test whether the short photoperiod was suitable for artificial storage, the life table data of were collected at 25 °C under a long photoperiod, 15:9 h (L:D), and a short photoperiod, 9:15 h (L:D) and analyzed using the age-stage, two-sex life table approach. We found that developed faster under long photoperiod than under the short photoperiod.

Development of a simplified ice-free cryopreservation method for heart valves employing VS83, an 83% cryoprotectant formulation.

We have previously demonstrated storage of ice-free cryopreserved heart valves at -80°C without the need for liquid nitrogen, with the aims of decreasing manufacturing costs and reducing employee safety hazards. The objectives of the present study were a further simplification of the ice-free cryopreservation method and characterization of tissue viability. Porcine pulmonary heart valves were permeated with an 83% cryoprotectant solution (VS83) followed by rapid cooling and storage at -80°C.

Allogeneic heart valve storage above the glass transition at -80°C.

Background: Cryopreserved allogeneic heart valves are usually stored and transported below -135°C; however, such methods require expensive equipment for both storage and transportation.

Methods: In this study, vitrified porcine aortic valves were stored on either side of the cryoprotectant formulation's glass transition temperature (-119°C) at -80°C and -135°C, using a newly formulated vitrification solution (VS83) consisting of a combination of 4.65M dimethyl sulfoxide, 4.

Vitrification of porcine articular cartilage.

The limited availability of fresh osteochondral allograft tissues necessitates the use of banking for long-term storage. A vitrification solution containing a 55% cryoprotectant formulation, VS55, previously studied using rabbit articular cartilage, was evaluated using porcine articular cartilage. Specimens ranging from 2 to 6 mm in thickness were obtained from 6mm distal femoral cartilage cores and cryopreserved by vitrification or freezing.

Quantitative second harmonic generation imaging of cartilage damage.

Cartilage damage was studied using non-invasive multiphoton-excited autofluorescence and quantitative second harmonic generation (SHG) microscopy. Two cryopreservation techniques based upon freezing and vitrification methods, respectively, were employed to determine whether or not the collagen fiber structure of full thickness porcine articular cartilage was affected by cryopreservation and whether the level of collagen damage could be determined quantitatively in non-processed (non-fixed, non-sliced, non-stained) tissues. Multiphoton-induced autofluorescence imaging revealed the presence of chondrocytes, as well as collagenous structures in all fresh, vitrified and frozen cryopreserved cartilage samples.