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Objective To explore the spatial distribution of microstructural parameters and mechanical properties for trabecular bone in the femoral head with osteonecrosis. Methods Microstructural parameters and mechanical properties of trabecular bone in different regions were analyzed by combined use of imaging measurements and numerical simulation method, and the spatial distribution of biomechanical properties for trabecular bone along coronal, sagittal and vertical directions was investigated. Results Microstructural characteristics and mechanical properties of trabecular bone were Y-shaped distributed along coronal and sagittal directions, and mechanical properties of trabecular bone in Y-shaped region were higher than those in the other regions. Such distribution characteristics was consistent with the location of principle compressive group in the femoral head. Conclusions Necrotic lesions in Y-shaped region had a greater influence on stress distribution of the femoral head and might cause the deterioration of osteonecrosis. The spacial correlation between necrotic lesions and Y-shaped region should be fully considered during clinical diagnosis.
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Objective To measure mechanical properties of calcified tissues from human aortic valve by nanoindentation test. Methods Leaflets from 5 patients with aortic stenosis were collected. Elastic modulus and hardness of the calcified leaflets were obtained by nanoindentationtest. Results The elastic modulus and hardness of the calcified leaflets were (15.69±3.89) GPa and (0.59±0.15) GPa, respectively. Conclusions The elastic modulus and hardness of the calcified valve tissues can be obtained by nanoindentationtest, which provides experimental data for biomechanical research of the valve.
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Objective@#To analyze the genetic characteristics of norovirus(NoV) in Jilin province from 2014 to 2016.@*Methods@#Stool samples from children under 5 years of age with diarrhea were collected from Changchun Children′s Hospital. Samples were amplified by RT-PCR. The polymerase and capsid gene of the positive specimens were amplified.Sequences were analyzed by homologous comparison and phylogenetic analysis.@*Results@#A total of 1 335 samples were detected, 177 were positive for NoV, and positive rate was 13.26%. The positive rate was 11.83% in 2014, 12.53% in 2015 and 15.75% in 2016. Genotyping of polymerase region revealed GII.P12 types dominated in 2014 and GII.Pe types dominated in 2015 and 2016. Genotyping of polymerase region revealed that GII.3 types dominated in 2014 and GII.4_Sydney2012 types dominated in 2015 and 2016. The types of both regions included GII.P17/GII.17, GII.Pe/GII.4_Sydney2012, GII.P12/GII.3, GII.Pe/GII.3、GII.P16/GII.2 and GII.P7/GII.6.@*Conclusions@#Genotypes of NoV infection are diverse in Jilin province. Most of them are recombinant strains. The main epidemic strains changed from GII.P12/GII.3 in 2014 to GII.Pe/GII.4_Sydney2012 in 2015 and 2016.
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Objective To develop an albumin aptamer that may potentially serve as a selective ligand for albumin removal from experimental samples.Methods A single-stranded 59nt DNA library that contains 21 random oligo nucleotides was synthesized in vitro.An albumin aptamer A6 was developed by SELEX technique using bovine serum albumin (BSA) as target.The enrichment of aptamer and evaluation of its binding properties were monitored by flow cytometry.The secondary structure of A6 was predicted by MFord software.Results The aptamer A6 strongly bound to BSA with a Kd of 77.4 nmol/L,and had minimal cross reactivity with control proteins including ovalbu min,IgG,and trypsin.Conclusions Aptamer A6 may be a potential tool in albumin removal.
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Objective To explore whether quercetin-loaded PEG-PE micelles(M-Q) can synergize the growth-in-hibitory activity of adriamycin prepared ( ADR) by reversing the drug resistance of MCF-7 ADRr breast cancer cells in vitro.Methods M-Q was prepared by adding saline to lipid film containing quercetin and PEG-PE.The size of M-Q was characterized by dynamic light scattering ( DLS) .The inhibition of MCF-7 ADRr cells was evaluated by MTS assay after incubation with M-Q and ADR.Results The incorporation efficiency of quercetin by the micelles was above 74%.The average size of M-Q was 11.11 nm.Compared with the quercetin dissolved in ethanol , M-Q more effectively reversed the drug resistance of MCF-7 ADRr cells in vitro.Conclusions PEG-PE micelles may potentially deliver quercetin to cancer cells for reversal of drug resistance .
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As the key component of immune system, dendritic cells (DCs) are the most competent antigen presenting cells. Compared with the conventional direct vaccination, in vitro treatment of DCs with tumor antigens generates more potent APC to stimulate antitumor response in vivo. This efficient cellular immuno-therapy is gaining increasing popularity in tumor vaccine preparation.
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The main objective of today’s graduate education reform is to improve the quality of graduate students. Curriculum development, as an essential part of graduate education, is pivotal to this goal. While classroom teaching innovation is placed in the front of curriculum development, it has become an important issue for graduate education study to practice an alternative capability centered way other than the current knowledge centered classroom teaching. We offered the course called "literature presentation and discussion" to the class 2006 graduate students at Chinese Academy of Medical Sciences. This article briefed and discussed the purpose,practice of this course,feedbacks from students and problems and solutions.