Objective:To investigate the application of digital teaching system in the teaching of onlay abutment teeth preparation for trainees receiving standardized residency training of stomatology (abbreviated as "resident trainees").Methods:The digital simulation teaching system unit was established by using the tissue morphology memory characteristics of 3Shape Trios oral scanner and Geomagic Control X 3D imaging design software. Eighteen resident trainees from the Daping Hospital were randomly divided into two groups, nine in the control group, preparing the onlay resin tooth model independently after taking the routine PPT + demonstration operation teaching; the other nine in the test group, preparing onlay model after learning digitization teaching system unit. All resident trainees prepared on three models respectively. After the teaching, the amounts of preparation and polymerization degree were compared between the two groups, making a summary teaching evaluation. Amounts of preparation, polymerization degree and teaching satisfaction were tested by independent-samples t-test with software SPSS 21.0. Results:Compared with the resident trainees in control group, the t values of width difference of buccal shoulder, lingual shoulder, proximal middle shoulder and distal middle shoulder, height difference of functional cusp and the lowest part of the proximal middle fossa, and degree of buccal polymerization, lingual polymerization and distal polymerization were 6.21, 6.12, 3.83, 4.73, 3.73, 4.79, 8.35, 4.35, and 6.69 respectively , while P values were respectively as <0.001, <0.001, <0.001, <0.001, 0.001, <0.001, <0.001, <0.001, and <0.001, with statistical difference ( P<0.05) . The t values of height difference of non-functional cusp, the lowest part of the distal middle fossa and degree of proximal polymerization were 1.02, 1.97, and 1.43, while P values were respectively 0.312, 0.054, and 0.158, with no statistical difference ( P>0.05). All indicators of teaching satisfaction were statistically significant ( P<0.05). Conclusions:The application of digital teaching system is conducive to improving the onlay abutment teeth preparation level of residents with high teaching satisfaction, which is worth promoting in clinical practice.

Osteoarthritis (OA), in which M1 macrophage polarization in the synovium exacerbates disease progression, is a major cause of cartilage degeneration and functional disabilities. Therapeutic strategies of OA designed to interfere with the polarization of macrophages have rarely been reported. Here, we report that SHP099, as an allosteric inhibitor of src-homology 2-containing protein tyrosine phosphatase 2 (SHP2), attenuated osteoarthritis progression by inhibiting M1 macrophage polarization. We demonstrated that M1 macrophage polarization was accompanied by the overexpression of SHP2 in the synovial tissues of OA patients and OA model mice. Compared to wild-type (WT) mice, myeloid lineage conditional Shp2 knockout (cKO) mice showed decreased M1 macrophage polarization and attenuated severity of synovitis, an elevated expression of cartilage phenotype protein collagen II (COL2), and a decreased expression of cartilage degradation markers collagen X (COL10) and matrix metalloproteinase 3 (MMP3) in OA cartilage. Further mechanistic analysis showed thatSHP099 inhibited lipopolysaccharide (LPS)-induced Toll-like receptor (TLR) signaling mediated by nuclear factor kappa B (NF-κB) and PI3K-AKT signaling. Moreover, intra-articular injection of SHP099 also significantly attenuated OA progression, including joint synovitis and cartilage damage. These results indicated that allosteric inhibition of SHP2 might be a promising therapeutic strategy for the treatment of OA.

Transrectal contrast-enhanced ultrasound (CEUS) is an important examination for rectal tumors. The inhomogeneity of the CEUS images has important clinical significance. However, there is no objective method to evaluate this index. In this study, a method based on gray-level co-occurrence matrix (GLCM) is proposed to extract texture features of images and grade these images according the inhomogeneity. Specific processes include compressing the gray level of the image, calculating the texture statistics of gray level co-occurrence matrix, combining feature selection and principal component analysis (PCA) for dimensionality reduction, and training and validating quadratic discriminant analysis (QDA). After ten cross-validation, the overall accuracy rate of machine classification was 87.01%, and the accuracy of each level was as follows: Grade Ⅰ 52.94%, Grade Ⅱ 96.48% and Grade Ⅲ 92.35% respectively. The proposed method has high accuracy in judging grade Ⅱ and Ⅲ images, which can help to identify the grade of inhomogeneity of contrast-enhanced ultrasound images of rectal tumors, and may be used to assist clinical doctors in judging the grade of inhomogeneity of contrast-enhanced ultrasound of rectal tumors.
Discriminant Analysis ; Humans ; Rectal Neoplasms ; Ultrasonography

Objective To find out if there is any difference in intercondylar fossa width and notch width index (NWI) between tibial intercondylar eminence avulsion fracture and anterior cruciate ligament (ACL) injury.Methods A retrospective study was conducted of the patients who had sought medical attention at Department of Sports Medicine and Adult Reconstructive Surgery,Drum Tower Hospital from June 2014 to May 2018.There were 10 patients with tibial intercondylar eminence avulsion fracture (4 males and 6 females with an average age of 32.7 ± 9.2 years),13 patients with ACL injury (8 males and 5 females with an average age of 31.8 ± 10.9 years) and 22 patients with simple meniscus injury as controls (13 males and 9 females with an average age of 30.9 ± 10.6 years).They all had MRI examination of the knee before surgery.The width of intercondylar fossa and the width and height of bilateral femoral condyles were measured on high resolution images of MRI axial view.NWI was calculated.The 3 groups were compared in intercondylar fossa width and NWI.Results The 3 groups of patients were comparable because there were no significant differences in gender,age,height,weight or BMI between them (P ＞ 0.05).The intercondylar fossa width in the ACL injury group (17.4 ± 3.5 mm) was significantly smaller than that in the avulsion fracture group (20.8 ± 1.1 mm) or in the control group (20.2 ±2.6 mm) (P ＜ 0.05),but no significant difference was detected between the avulsion fracture group and the control group (P ＞ 0.05).NWI in the avulsion fracture group (0.301 ±0.011) was similar to that in the control group (0.280 ±0.039) (P ＞ 0.05) but significantly higher than that in the ACL injury group (0.25 ± 0.05) (P ＜ 0.05).NWI in the ACL injury group was significantly lower than that in the control group (P ＜ 0.05).Conclusions Intercondylar notch stenosis may be a risk factor for ACL injury but may not be associated with tibial intercondylar eminence avulsion fracture.The difference in pathogenesis between tibial intercondylar eminence avulsion fracture and ACL injury may be associated with their difference in NWI.

OBJECTIVE To clarify the long-term toxicity to the respiratory system in a rat model of acute lung injury (ALI) induced by a single low-dose of perfluoroisobutylene(PFIB) inhalation expo?sure,and observe the possible beneficial effect of early intervention via Qingkailing(QKL) injection. METHODS Totally 224 male Wistar rats were randomly divided into 4 groups:normal control group in which air exposure was followed by a saline 10 mL · kg-1(ip),QKL control group in which QKL 10 mL · kg-1 was ip given after air exposure,PFIB exposure group in which rats were exposed to PFIB 280 mg·m-3 for 5 min only,and QKL treatment group in which QKL 10 mL·kg-1 was given ip at 1 h after PFIB exposure. Lung functions of rats were measured at 24 h,3,6,12,24,36 and 48 weeks after exposure. The arterial blood gas,lung coefficient,protein content in bronchoalveolar lavage fluid(BALF),hydroxy?proline(HYP) content in lung tissue and plasma,and other indicators were detected or analyzed. RESULTS Within 24 h after PFIB exposure,the lung coefficient and protein content in BALF were increased significantly(P<0.01),whereas the PaO2(P<0.01) and SaO2(P<0.05) indices in arterial blood decreased significantly in PFIB group compared with normal control. The inhalation time , exhalation time,tidal volume(TV),expired volume(EV)and relaxed time were reduced significantly (P<0.01). However,all the above indicators returned to normal in 3 weeks,but TV,EV and peak expiratory flow were significantly lower than in normal group at 48 weeks(P<0.05). HYP contents in lung tissues,compared with normal control(P<0.05),were reduced significantly within 24 h after PFIB exposure,increased significantly in 6 weeks(P<0.05),then returned to normal in 12 weeks. HYP contents in plasma increased significantly compared with normal control(P<0.05) within 24 h after PFIB exposure but returned to normal in 3 weeks. The protein contents in BALF of QKL treatment group were significantly lower than those in PFIB group(P<0.01) within 24 h after PFIB exposure. From 24 h to 24 weeks after PFIB exposure,changes of pulmonary functions were similar to those in PFIB group. At 48 weeks,TV and EV in QKL treatment group were more significantly increased than those in PFIB group(P<0.05). CONCLUSION Rats with ALI induced by a single low dose of PFIB exposure undergo compensatory repair except for pulmonary capacity and pulmonary ventilation functions. Early treatment with QKL reduces protein content of BALF and alleviates pulmonary edema,and has some beneficial effect on lung function recovery later.

This paper proposes a technique to denoise the worm artifacts of elastogram using 2-D wavelet shrinkage denoising method. Firstly, strain estimate matrix including worm artifacts was decomposed to 3 levels by 2-D discrete wavelet transform with Sym8 wavelet function, and the thresholds were obtained using Birg6-Massart algorithm. Secondly, all the high frequency coefficients on different levels were quantized by using hard threshold and soft threshold function. Finally, the strain estimate matrix was reconstructed by using the 3rd layer low frequency coefficients and other layer quantized high frequency coefficients. The simulation results illustrated that the present technique could efficiently denoise the worm artifacts, enhance the elastogram performance indices, such as elastographic signal-to-noise ratio (SNRe) and elastographic contrast-to-noise ratio (CNRe), and could increase the correlation coefficient between the denoised elastogram and the ideal elastogram. In comparison with 2-D low-pass filtering, it could also obtain the higher elastographic SNRe and CNRe, and have clearer hard lesion edge. In addition, the results demonstrated that the proposed technique could suppress worm artifacts of elastograms for various applied strains. This work showed that the 2-D wavelet shrinkage denoising could efficiently denoise the worm artifacts of elastogram and enhance the performance of elastogram.
Algorithms ; Artifacts ; Elasticity Imaging Techniques ; methods ; Humans ; Image Processing, Computer-Assisted ; Wavelet Analysis

In order to get real time ultrasound images with clear structure and improved contrast, an adaptive ultrasound sound speed optimization method based on image contrast analysis was investigated. It firstly introduced the dynamic beamforming of ultrasound system, as well as the definition of assumed system's sound speed and the true sound speed propagated in tissues the degrade image quality due to their mismatch was also discussed. After given the pixel gray level value based ultrasound image contrast ratio, the basic idea to precisely estimate the true sound speed for real time system sound speed was proposed. Algorithms have been verified both in tissue-mimicking phantoms with known sound speeds and in vivo ultrasound images, compared with other existing method. The testing results showed that this new method not only produced accurate sound speed for ultrasound image optimization, but also finely met the critical computation requirement for real time applications.
Algorithms ; Humans ; Image Enhancement ; methods ; Image Interpretation, Computer-Assisted ; Phantoms, Imaging ; Sound ; Ultrasonography ; instrumentation ; methods

Objective: To observe the effect of hypoxia on changes of proliferation ability of cultured human periodontal ligament fibroblasts (HPLFS) in vitro. Methods: HPLFS were randomly divided into two groups (experimental group and control group) by different oxygen concentrations. The oxygen concentration of control group was 21%. The oxygen concentrations of experiment group were 10%, 5% and 2%. The proliferation ability of HPLFS was detected by MTT colorimetric assay. The cell ultrastructure was observed by transmission electron microscope (TEM). Results: MTT assay results showed that compared with the control group, at the 12 h and 24 h, cell proliferation was enhanced with the hypoxia degree. At 24 h, cell proliferation showed significant differences. At 48 h and 72 h, proliferation of the cultured HPLFS in severe hypoxia group reduced significantly. Observed by TEM, at 24 h, not only the number of mitochondria, rough endoplasmic reticulum but also cell process increased in the cultured HPLFS in severe hypoxia group. At 72 h, the number of lysosome increased and the cell structure degenerated. Conclusion: Long-time severe hypoxia may lower the repair and remodeling abilities of periodontium, which might be one of the important etiological factors of periodontal disease under condition of high altitude.

In this paper the theory of autocorrelation algorithm for color flow mapping is analyzed and a new way for ultrasound color flow velocity estimation and real-time display is proposed. The method sets up a mapping table which directly relates to the dynamic display range and has only 256 entries using an inverse mapping method instead of calculating the arctangent value directly. This method is ideal for software implementation and offers an interactive way to the user for changing the dynamic range of flow velocity and thus to increasing the display resolution.
Algorithms ; Blood Flow Velocity ; Humans ; Pulsatile Flow ; physiology ; Rheology ; instrumentation ; Ultrasonography, Doppler, Color ; instrumentation ; methods

0.05).Conclusion The administration of helicid to pregnant rats did not affect the early development of nervous system, neurobehavioral function and brain histology of offspring.