A new method for multi-protocol label switching is presented in this study, whose core idea is to construct model for simulating process of accommodating network online loads and then adopt genetic algorithm to optimize the model. Due to the heuristic property of evolutional method, the new method is efficient and effective, which is verified by the experiments.

A new method for multi-protocol label switching is presented in this study, whose core idea is to construct model for simulating process of accommodating network online loads and then adopt genetic algorithm to optimize the model. Due to the heuristic property of evolutional method, the new method is efficient and effective, which is verified by the experiments.

Objective To analyze the clinical characteristics of Mycoplasma pneumoniae pneumonia in children under 2 years old. Methods The clinical features and treatment outcomes were analyzed in 57 children under 2 years old and compared with 153 children more than 2 years old. Results Compared with children more than 2 years old, in children under 2 years old, the number of cases with fever was fewer, the fever peak was lower and the lasting time was shorter. However, in children under 2 years old, the severe pulmonary signs were more common, the incidence of wheeze was higher, meanwhile, the count of white blood cells (WBCs) was signiifcantly increased, more small pieces of lfuff shadow was showed on chest X-ray, and the pulmo-nary complications were fewer, less corticosteroid was needed for treatment. After one-week therapy, the chest X-ray shadows were disappeared in most of children. Complications out of lungs, such as rash, liver function damage and cardiac damage can be found in both groups and no signiifcant difference (P>0.05). Conclusions Mycoplasma pneumoniae pneumonia in children under 2 years old had the characteristics of mild symptoms, severe pulmonary signs, few pulmonary complications, light systemic inlfammations and mild radiological changes.

A new method for multi-protocol label switching is presented in this study, whose core idea is to construct model for simulating process of accommodating network online loads and then adopt genetic algorithm to optimize the model. Due to the heuristic property of evolutional method, the new method is efficient and effective, which is verified by the experiments.

The truncated binary exponential back-off algorithm is one of the most effective methods applied in collision resolution process of random multi-access channel. In this study, two new strategies are presented to improve the capability of the truncated binary exponential back-off algorithm. In the new strategies, the sizes of the initial window size or the operating window sizes are adjusted dynamically, which always bring a significant improvement for the self-adaptability of the original algorithm. A series of experiments are simulated and the results verify that the new strategies can make the implementation more stable and effective than the original algorithm.

Objectives To explore the humoral immunologic mechanisms of the susceptibility to invasive pneumococcal diseases (IPD) in asthmatic children. Methods Plasma samples were collected from 43 asthmatic and 20 non-asthmatic chil-dren. Anit-pneumococcal capsular polysaccharide (PPS)-IgG concentrations were measured by enzyme-linked immunosorbent assays. Results The mean concentrations of anti-PPS 14, 19A and 23F-IgG were signiifcantly higher in asthmatic children than in non-asthmatic children (P<0.05). The ratios of the asthmatic children who had anti-PPS 14, 19A and 23F-IgG concentrations higher than the protective antibody level (≥0.2 μg/ml ) were 100%for all the serotypes. Conclusions The immune responses of producing anti-PPS IgG to defense IPD were normal in asthmatic children. Asthmatic children may be more susceptive to pneumococcal infection or colonization than non-asthmatic children.

BACKGROUND: Presently, the biomaterial used in ligament tissue engineering such as collagen protein, polylactic acid, polyglycolic acid, small intestinal submucosa, glycan and nanomaterial are characterized by rapid degradation, resulting in inflammatory reaction after applying in host.OBJECTIVE: To investigate mechanical strength and in vitro degradation of silk scaffold and explore the reaction to macrophages.DESIGN: Controlled experiment.SETTING: Experiments were performed at the Department of Orthopaedics, Union Hospital, Huazhong University of Science and Technology from September 2004 to January 2005.MATERIALS: White raw Bombyx mori silkworm fibers of size 20/22 (according to the manufacturer) were obtained from the market. Bundles of 30 parallel fibers were prepared for a bundle of scaffold, which was put into fervens 5g/L Na2CO3for degumming. Ratio of Na2CO3 solution (Ml) to raw silk (g) was 1000.METHODS: In vitro degradation: 8cm long silk scaffold was weighed after drying. Subsequently, the silk scaffold was separately dipped into phosphate buffer saline (PBS) and 1.0g/L collagenase prepared with PBS. Twelve weeks later, silk scaffold was weighed to calculate weight loss rate. Simultaneously, tensile test was performed to detect the ultimate tensile strength (UTS) of samples. Culture of monocyte strain RAW264.7:2×108L-1 macrophage suspension (1mL) were separately added in a silk scaffold group, a control group and a lipopolysaccharide (LPS) group. At days 1 and 7, cell supernatant was collected from each group. Tumor necrosis factor-α(TNF-α) levels were measured by enzyme linked immunosorbent assay (ELISA).MAIN OUTCOME MEASURES: ① Changes in weight loss rate and UTS of the silk matrices after incubated with collagenase and the PBS. ②TNF-αlevels in the supernatant of each groups at days 1 and 7.RESULTS: Mass of silk matrices reduced by over 50% after incubated with collagenase for 8 weeks, but no change was found in PBS. UTS decreased by over 50% 8 weeks after incubated with collagenase, but no change was detected in PBS. At days 1 and 7, TNF-α levels in the supernatant was less in the silk scaffold group; TNF-α levels in the supernatant was significantly higher in the LPS group than in the silk scaffold group (P<0.01), but no significant difference in TNF-α levels was measured between the silk scaffold group and the control group (P>0.05).CONCLUSION: After 12-weeks degradation, silk scaffold still has good mechanical properties. Macrophages possess immunological inertia at days 1 and 7 after inoculated with macrophages.

In order to investigate the effect of Arg-Gly-Asp (RGD) peptide-modified silk biomaterial on the adhesion and proliferation of bone marrow-derived mesenchymal stem cells (MSCs), MSCs of third generation were seeded onto the surface of RGD-decorated silk (silk-RGD group), silk alone (silk group) or tissue culture plate (TCP group). After incubation for 4 or 12 h, MSCs were examined quantitatively by using precipitation method for cell attachment. The cell proliferation, which was defined as cell density, was compared among the three groups after culture for 1, 2, 3, and 4 days. Cell skeleton, which was labeled fluorescently, was observed under laser confocal microscope after 24 h of culture. The results showed that cell adhesion rate in silk-RGD group was higher than in silk group (P<0.05), but similar to that in TCP group after incubation for 4 or 12 h (P>0.05). There were no significant differences in the cell proliferation among the three groups at different time points (P>0.05 for all). Laser confocal microscopy revealed that in silk-RGD group, MSCs, strongly fluorescently stained, spread fully, with stress fibers clearly seen, while in silk group, actin filaments were sparsely aligned and less stress fibers were found. It was concluded that RGD peptide could improve the adhesion of MSCs to the silk scaffold, but had no impact on the proliferation of the cells.
Biocompatible Materials/*chemistry ; Bone Marrow Cells/cytology ; Cell Adhesion/drug effects ; Cell Proliferation/drug effects ; Mesenchymal Stem Cells/*cytology ; Oligopeptides/*chemistry ; *Silk/chemistry ; Tissue Scaffolds

BACKGROUND:There are several reports about the application of fresh bone marrow aspirate being injected directly to repair partial ligament injury, but the application about fresh bone marrow aspirate directly being planted on scaffolds to build tissue-engineered ligament is rarely mentioned.
OBJECTIVE:To evaluate the feasibility of applying fresh bone marrow aspirate planted directly on scaffolds to construct tissue-engineered ligament
METHODS:We constructed fibroin fiber/smal intestinal submucosa composite scaffold, then planting fresh bone marrow directly to built bone marrow seeding group and planting seed cel s (bone marrow mesenchymal stem cel s) on the scaffold to built cel seeding group. The control group had no treatment. After that, we detected the density of cel adhesion, cel proliferation ability and extracel ular matrix secretion. Then, the composite in the bone marrow seeding group was implanted into the broken anterior cruciate ligament in rabbits, and material biocompatibility in vivo was evaluated after 12 weeks.
RESULTS AND CONCLUSION:After 4 hours of incubation, bone marrow seeding group was significantly higher than the cel seeding group in cel adhesion density and proliferation rate (P<0.05). Bone marrow seeding group and cel seeding group showed higher type I, III col agen secretion compared with the control group (P<0.05), but the col agen secretion of bone marrow seeding group and cel seeding group showed no significant difference. Composite cel scaffold implantation in vivo did not cause fatal immune rejection and severe inflammatory reaction, and no significant ligament regeneration and vascularization occurred. These findings indicate that fresh bone marrow aspirate can be seeded directly on scaffolds to construct tissue-engineered ligament, and the short-term biocompatibility in vivo is good.

0.05).CONCLUSION:The excellent mechanical properties of composite ligament can meet the mechanical requirements of appropriate ligament tissue engineering scaffolds.