[From Passive Application to Active Design -Restructuring and Reshaping of Core Specialty Knowledge Systems of Biomedical Engineering (Biomedical Materials Track) Undergraduate Education].

Biomedical engineering (BME) (biomedical materials track) is a typical field of interdisciplinary integration. Its specialty education simultaneously undertakes the duo reformation responsibilities for the new engineering education and the new medical education due to its unique strengths in interdisciplinary nature, comprehensive scope of knowledge, and status of being on the cutting edge of technology. We made an analysis, in this paper, of the opportunities and challenges faced by BME (biomedical materials track) specialty education on the basis of the trends and frontiers of development in biomedical materials in the world. From the perspective of new requirements raised by major national strategies and industrial development for the qualifications and competence of professionals specializing in biomedical materials, thorough reflections were made on the specialized education of BME (biomedical materials track) under the background of the new engineering education and the new medical education. Furthermore, we proposed herein to reconstruct the specialized core knowledge system according to the main line of the reactions and the responses between the biomedical materials and human bodies at different levels and set up a series of courses of biomedical materials science centered on Materiobiology as the core. We also proposed to establish a diversified integrated reform model of the training system incorporating production, learning, research and application for highly competent BME (biomedical materials track) professionals. This paper attempts to contribute to the solution of the major issue of how to train the innovative talents and leaders who will pioneer a new round of diagnosis and treatment technology revolution and the development of the medical device industry.

A novel TIRADS of US classification.

BACKGROUND: Thyroid imaging reporting and data system (TIRADS) is the assessment of a risk stratification of thyroid nodules, usually using a score. However, there is no consensus as to the version of TIRADS for reporting the results of thyroid ultrasound in clinic. The objective of this study is to develop a practical TIRADS with which to categorize thyroid nodules and stratify their malignant risk. METHODS: A TIRADS scoring system was developed to provide more decision levels than standard scoring through the selection of the ultrasound features which include the calcification shape, margins, taller-than-wide, internal echo, blood flow quantization of features, setting of the weight, and calculation of the score. Ultimately, the accuracy of our TIRADS was evaluated by comparing with the results of current vision of TIRADS and thyroid radiologist in 153 patients who had US-guided fine-needle aspiration biopsy. RESULTS: Classification results showed that the total accuracy reached 97% (100% of malignant and 95% of the benign) in 153 cases (benign:78, malignant:75). The percentages of malignancy is defined in our TIRADS were as follows: TIRADS 2 (0% malignancy), TIRADS 3 (3.6% malignancy), TIRADS 4 (17-75% malignancy), and TIRADS 5 (98% malignancy). CONCLUSIONS: We established a novel TIRADS to predict the malignancy risk of the thyroid nodules based on six categories US features by a scoring system, which included a standardized vocabulary and score and a quantified risk assessment. The results showed that objective quantitative classification of thyroid nodules by our TIRADS can be useful in guiding management decisions.

[Ultrasound tissue characterization of hepatic fat in rats using radiofrequency signal analysis].

OBJECTIVE: To investigate the significance of multi-parameter quantitative evaluation of hepatic fat using ultrasound radiofrequency signal analysis. METHODS: Thirty two SD rats were divided into two groups, with 24 having fatty livers and 8 serving as normal controls. Radiofrequency signals were sampled with a 13-MHz ultrasound probe and digitized at 40 MHz in 16-bit resolution. Four statistical parameters of the radiofrequency envelope [Mean, Mean/SD ratio (MSR), skewness (SK), and kurtosis (KU)] within the ROI were calculated offline, and their ability to diagnose fatty liver was analyzed. RESULTS: The rats with fatty livers had greater Mean and MSR but lower skewness and kurtosis than the controls. The areas under the ROC curve of Mean, MSR, skewness and kurtosis for diagnosing fatty livers were 0.85, 0.96, 0.98, and 0.98 respectively. The sensitivity and specificity of Mean, MSR, skewness and kurtosis for diagnosing fatty livers were 70.8%/88.9%, 87.5%/100%, 95.8%/100% and 95.8%/100% respectively, whereas conventional ultrasound achieved only 68.2% in sensitivity and 66.7% in specificity. CONCLUSION: Compared with conventional ultrasound, radiofrequency signal analysis is more accurate in diagnosing fatty livers.

Automatic segmentation of echocardiography based on a morphological reconstruction algorithm.

OBJECTIVE: To improve the precision of the traditional segmentation of echocardiogram, by suppressing the influence from inherent speckle noises in medical ultrasonic images. METHOD: An automatic segmentation method based on reconstructed morphology was proposed in this paper. First, the opening and closing operations by reconstruction were imposed to the ultrasonic image. Second, the top-hat operation was used to extract the bright and/or dark features and to find out the boundaries corresponding to these features, whereby implemented the automatic segmentation. RESULT: The segmented echocardiogram had less artificial boundaries resulted from speckle noise, and could accurately be extracted the artery and ventricle. CONCLUSION: The presented method can detect both dark and bright objects accurately, and the boundary has a fine continuity. In addition, the algorithm is also applicable to the extraction of sole bright/dark features, accordingly to reduce the complexity and time needed and to improve the accuracy.

[A medical ultrasonic image filtering method based on anisotropic diffusion].

OBJECTIVE: To remove the speckle noise in ultrasonic images by using anisotropic diffusion method. METHOD: Based on anisotropic diffusion, a partial differential equation, of which the initial data was the input images, was transformed into differential forms and solved with iterations. The speckle scale function of the equation was modified to make better use in filtering medical ultrasonic images. RESULT: By comparing the results with other three filters, the anisotropic diffusion method could smooth the speckles very well and the edge of the image was also clear. CONCLUSION: Anisotropic diffusion can remove the speckle noise effectively and has great potential in filtering medical ultrasonic images.

Correlation between the Xba I polymorphism of apoB gene and serum lipid profiles in Li ethnic group.

OBJECTIVE: To study correlation between the Xba I polymorphism of apoB gene and plasma lipid profiles in Li ethnic group. METHODS: Total 151 cases of healthy Li people were recruited randomly by cluster sampling and 200 Han people were recruited as control; blood was drawn to analyze Xba I polymorphism distribution of apoB gene and serum lipid levels. RESULTS: There were lower serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) levels in serum of Li people; while, high density lipoprotein cholesterol (HDL-C), X-/X+ genotype and X+ allele frequencies exhibited higher levels than Han people. Interestingly, HDL-C level was reduced, while LDL-C level was enhanced in subjects carrying heterozygous (X-/X+) genotype compared to homozygous (X-/X-) genotype. Additionally, there were no difference in serum level of triglyceride, TC, apoprotein A (apo A) and apoprotein B (apo B) between Li and Han people, the same results were showed between X-/X+ and X-/X- genotype carriers. CONCLUSIONS: Xba I polymorphism of apoB gene is correlated to the profiles of serum lipid level, X-/X+ genotype carriers are phenotyped with higher LDL-C level and lower level of HDL-C in Li ethnic group.

Expression level of pluripotent genes in incomplete reprogramming

OBJECTIVE@#To compare the expression levels of pluripotent genes among incomplete reprogrammed colonies and induced pluripotent stem cells (iPSCs), to explore the relationship between the expression of pluripotent genes and incomplete reprogramming.@*METHODS@#Four genes (Oct4, Sox2, Klf4, C-Myc) were introduced into human foreskin fibroblasts (HFFs) by retroviruses. The HFFs were induced to reprogramming. Different forms of colonies were picked up, analyzed, and compared with iPSCs from different aspects, including the morphology of clones, alkaline phosphatase (AP) staining, immuno-fluorescence, and Q-PCR.@*RESULTS@#In the reprogramming process, different colonies were emerged, some of them exhibited typical human embryonic stem cell morphology (eg., compact colonies, high nucleus-to-cytoplasm ratios, and prominent nucleoli). However, these colonies couldn't maintain these characters after passage. There was an intermediate state, named partially reprogramming. Through analysis and identification, AP staining results were weakly positive, compared with iPSC colonies. The immuno-fluorescence staining demonstrated these colonies just expressed pluripotent protein Oct4. Q-PCR indicated that the expression of exogenous transcription factors was inappropriate, either at a high level or at a low level. Most of the endogenous pluripotency genes were expressed at a low level.@*CONCLUSIONS@#It may be one of the causes of incomplete reprogramming that the exogenous pluripotent gene is low-expressed or over-expressed, and successful reprogramming may depend on a specific stoichiometric balance of Oct4, Sox2, Klf4 and c-Myc.