ABSTRACT
PURPOSE@#Child head injury under impact scenarios (e.g. falls, vehicle crashes, etc.) is an important topic in the field of injury biomechanics. The head of piglet was commonly used as the surrogate to investigate the biomechanical response and mechanisms of pediatric head injuries because of the similar cellular structures and material properties. However, up to date, piglet head models with accurate geometry and material properties, which have been validated by impact experiments, are seldom. We aim to develop such a model for future research.@*METHODS@#In this study, first, the detailed anatomical structures of the piglet head, including the skull, suture, brain, pia mater, dura mater, cerebrospinal fluid, scalp and soft tissue, were constructed based on CT scans. Then, a structured butterfly method was adopted to mesh the complex geometries of the piglet head to generate high-quality elements and each component was assigned corresponding constitutive material models. Finally, the guided drop tower tests were conducted and the force-time histories were ectracted to validate the piglet head finite element model.@*RESULTS@#Simulations were conducted on the developed finite element model under impact conditions and the simulation results were compared with the experimental data from the guided drop tower tests and the published literature. The average peak force and duration of the guide drop tower test were similar to that of the simulation, with an error below 10%. The inaccuracy was below 20%. The average peak force and duration reported in the literature were comparable to those of the simulation, with the exception of the duration for an impact energy of 11 J. The results showed that the model was capable to capture the response of the pig head.@*CONCLUSION@#This study can provide an effective tool for investigating child head injury mechanisms and protection strategies under impact loading conditions.
Subject(s)
Animals , Swine , Finite Element Analysis , Skull/injuries , Craniocerebral Trauma/diagnostic imaging , Brain , Biomechanical Phenomena , ScalpABSTRACT
<p><b>OBJECTIVE</b>To design DNA microarray and investigate the molecular anti-tumor mechanism of herbs of traditional Chinese medicine.</p><p><b>METHOD</b>cDNA microarrays consisting of 56 probes representing 24 human cell cycle genes were constructed, Four anti-hepatocarcinoma herbs including Radix Linderae, Hebra Artemisiae Annuae, Radix Amebiae, Radix Astragli, were chosen. Effects of herbs on SMMC-7721 cell cycle were observed by flow cytometry assay. Effects of herbs on cell cycle gene expression in SMMC-7721 cells were analyzed by comparing hybridization of Dig-Labeled cDNAs from herb-treated cells and cDNAs from untreated cells.</p><p><b>RESULT</b>Expressions of cell cycle geneswere changed in different degrees after herbs treated. Some genes were down-regulated and some genes were up-regulated. The changes in gene expression agreed with the results of flow cytometry assay.</p><p><b>CONCLUSION</b>The results suggest that these herbs may have effects on cell cycle and DNA damage checkpoint genes which may be the mechanism of the herbs, and DNA microarray can be used to investigate the biological function of extracts of traditional Chinese medicine.</p>
Subject(s)
Humans , Antineoplastic Agents, Phytogenic , Pharmacology , Artemisia , Chemistry , Astragalus propinquus , Chemistry , Carcinoma, Hepatocellular , Metabolism , Pathology , Cell Line, Tumor , Cyclin-Dependent Kinase 4 , Cyclin-Dependent Kinase Inhibitor p16 , Genetics , Metabolism , Cyclin-Dependent Kinases , Genetics , Metabolism , Drugs, Chinese Herbal , Pharmacology , Gene Amplification , Gene Expression Profiling , Genes, cdc , Lindera , Chemistry , Lithospermum , Chemistry , Liver Neoplasms , Metabolism , Pathology , Oligonucleotide Array Sequence Analysis , Methods , Plants, Medicinal , Chemistry , Proliferating Cell Nuclear Antigen , Genetics , Metabolism , Proto-Oncogene Proteins , Genetics , Metabolism , cdc25 Phosphatases , Genetics , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To screen and identify the differentially expressed genes in hepatocellular carcinoma cells SMMC-7721 responsing to the aqueous extract from dried powdered rhizomes of Typhonium giganteum (AEoTGE).</p><p><b>METHOD</b>The response of hepatocellular carcinoma cells SMMC-7721 to AEoTGE was explored with the technique of mRNA differential display.</p><p><b>RESULT</b>After hepatocarcinoma cells SMMC-7721 were treated by AEoTGE for 36 hours, 1 gene expression was upgrade and 1 gene expression was downgrade induced by AEoTGE.</p><p><b>CONCLUSION</b>The research has provided important clues for the molecular mechanism of how hepatocarcinoma cells responseing to T. giganteum.</p>