Codewords Distribution-Based Optimal Combination of Equal-Average Equal-Variance Equal-Norm Nearest Neighbor Fast Search Algorithm for Vector Quantization Encoding.

Vector quantization encoding requires expensive time to find the closest codeword through the codebook for each input vector. A fast search algorithm for encoding is proposed in this paper. The multilevel elimination criterion is still derived from the three features (mean, variance, and norm) inequalities constraints, but the order of the three inequalities constraints, instead of the predefined order like other conventional multilevel elimination criterion, is optimized to speed up the encoding procedure. In the proposed algorithm, the elimination criterion at the first level is set to mean inequality constraint because of its narrower search width, and the priority order at the second and/or third level of variance and norm inequalities constraints is optimized based on the codewords distribution and the location of input vector in terms of the considered features. The experimental results demonstrate the effectiveness of the proposed algorithm.

Effects of mechanical stimulation on proliferation activity and CTGF expression of sclera fibroblasts / 医用生物力学

Objective To study the effects of mechanical stimulation on proliferation activity and connective tissue growth factor(CTGF) expression of sclera fibroblasts. Method The sclera fibroblasts from New Zealand white rabbits were obtained by tissue pieces culture method and identified with immunocytochemistry method, as well as tested by FX 4000 Tension System (sine wave, 3% and 6% elongation amplitude, 0.1Hz, 48h duration). The proliferation activity and concentration of CTGF were measured by ATP based bioluminescence method and ELISA method, respectively. ResultsExperimental studies have shown that the proliferation activity of the scleral fibroblasts in 3% group (2.352±0.123) and 6% group (2.784±0.119) are significantly higher when compared with control group (1.901±0.092) (P<0.05), and the proliferation activity in 6% group is significant higher than that in 3% group (P<0.05); The CTGF expression of 3% group (control group: (0.291±0.118)μg/L, 3% stretch group: (1.623±0.276)μg/L） and 6% group (control group: (0.260±0.112)μg/L, 6% stretch group: (3.205±0.287)μg/L) are both significantly increased compared with each of their respective control groups (P<0.05). Conclusions Mechanical stimulation plays an important role in the proliferation activity and CTGF expression of scleral fibroblasts.