OBJECTIVEThis study aims to identify the crack tip stress intensity factor of the propagation process, crack propagation path, and the changes in the shape of the crack tip by the finite element method.

METHODSThe finite element model of dentino-enamel junction was established with ANSYS software, and the length of the initial crack in the single edge was set to 0.1 mm. The lower end of the sample was fixed. The tensile load of 1 MPa with frequency of 5 Hz was applied to the upper end. The stress intensity factor, deflection angle, and changes in the shape of the crack tip in the crack propagation were calculated by ANSYS.

RESULTSThe stress intensity factor suddenly and continuously decreased in dentino-enamel junction as the crack extended. A large skewed angle appeared, and the stress on crack tip was reduced.

CONCLUSIONThe dentino-enamel junction on human teeth may resist crack propagation through stress reduction.

Objective To establish a method for the determination of berberine hydrochloride and phellodendrine in Lishukang Capsules by HPLC. Methods Waters Symmetry C18 column (4.6 mm× 250 mm, 5μm) was used, the mobile phase was acetonitrile-0.1%phosphoric acid (0.1 g sodidum dodecyl sulfonate in 100 mL water), with the flow rate of 1 mL/min by gradient elution. The detection wavelength was set at 284 nm. Results Berberine hydrochloride showed good linear relationship (r 2=0.999 1) in the range of 403.4-10 084.7 μg, the average recovery rate was 99.8%(RSD=1.7%). Phellodendrine showed good linear relationship (r 2=0.999 2) in the range of 169.137 6-4228.44 μg, the average recovery rate was 95.5%(RSD=3.2%). Conclusion The method is specific, accurate and convenient to be used for the quality control of Lishukang Capsules.

ObjectiveTo explore the biological features of colorectal adenoma with chicken-skin mucosa ( CSM ) and its clinical significance.MethodsExpression of cell proliferation markers ( Ki-67 and COX-2) and apoptosis-related factors ( survivin and caspase-3) in normal colorectal mucosa,colorectal adenoma without CSM,colorectal adenoma with CSM and colorectal adenocarcinoma were detected by immunohistochemistry SP method and enzyme-linked immunosorbent assay (ELISA).ResultsImmunohistochemical results revealed a decreased trend in expressions of Ki-67 and COX-2 from colorectal adenocarcinoma through colorectal adenoma with and without CSM to normal colorectal mucosa,while the expressions of survivin and caspase-3 showed an increased trend.By ELISA,the expressions of Ki-67,COX-2,surviving and caspase-3 showed no significant difference (P ＞ 0.05 ) between colorectal adenoma with CSM and coloreetal adenocarcima,while these variables were significantly different (P ＜ 0.05) between coloreetal adenoma with and without CSM,so as well between normal colorectal mucosa and other 3 groups.ConclusionThe biological characteristics of colorectal adenoma with CSM are different from those without,showing an activated cell proliferation and inhibited cell apoptosis with increased carcinogenesis risk.

Objective To analyze the features of normal high-frequency ultrasonography of tarsal tunnel. Methods Forty volunteers (20 males and 20 females) were examined with high-frequency ultrasound (12 MHz). The tendons,nerve and blood vessels in tarsal tunnel were observed from short-axis and long-axis views dynamically. The areas of tarsal tunnel and posterior tibial nerve were measured and com-pared between the males and females. Results High-frequency ultrasonography depicted the anatomical structure of tarsal tunnel,and the tendons,nerve and blood vessels presented different sonographic features that were easy to differentiate. The area of tarsal tunnel: male (7.61 ±1.00) cm2,female (6. 61 ± 1. 07) cm2 (P <0. 01). The area of posterior tibial nerve: male (9. 59 ± 0. 75) mm2,female (8.91 ±0.74) mm2(P<0.01). Conclusion High-frequency ultrasonography can clearly show and accurately measure the tarsal tunnel structure. To be familiar with the normal ultrasonographic anatomy of tarsal tunnel will help to improve the efficacy of ultrasound diagnosis of tarsal tunnel abnormalities.

Objective To evaluate the efficacy and safety of Qingpeng ointment for the treatment of localized dermatitis and eczema in children.Methods Sixty-eight outpatient children with localized dermatitis or eczema were included in this study.All the patients were topically treated by Qingpeng ointment twice daily for a week,which was agreed by their patients.The efficacy was evaluated after the end of the treatment by lesion scores,and adverse reactions during the treatment were recorded.Results Of the 68 patients,61 completed the trial,7 withdrew from the trial because of worsened lesions,unfavorable effects and distrust of this drug.The total response rate was 81.4％ (31/51) in patients treated with Qingpeng ointment alone.Irritant reaction occured in only one case,but did not influence the treatment.Conclusion Qingpeng ointment displays a favorable efficacy and safety in the treatment of localized dermatitis and eczema in children.

Obesity as a global issue is a serious threat to children's health.To control childhood obesity must begin with effective preventions.Most studies have found that breast milk can protect against childhood obesity.It is recommended that children should be exclusively breastfed for at least 4-6 months.The duration of breastfeeding has some negative correlation with the prevalence of childhood obesity.Increasing the duration of breastfeeding can properly decrease the risk of childhood obesity.

Objective To establish an HPLC method for determining the content of swertiamarin in Gantaishu capsules. Methods Using a Waters Symmetry C18 column (4.6 mm×250 mm, 5μm), the mobile phase was acetonitrile-0.02%phosphoric acid, with flow rate of 1.0 mL/min. The detection wavelength was at 250 nm, the column temperature was room temperature. Results The content of swertiamarin showed a good linear relationship in the range of 0.373 556-2.988 448 μg, r 2=1.000 0. The average recovery was 106.81%, and RSD was 3.7%. Conclusion This method is fast, accurate and simple with good reproducibility, which can be applied to the quality control of Gantaishu capsules.

Objective To investigate the expression of CDX2 in different subtypes of intestinal metaplasia (IM) and gastric cancer,and its relationship with Helicobacter Pylori (H.pylori) infection.Methods The expressions of CDX2 protein were detected with immunohistochemical method in 42 cases of chronic atrophic gastritis (CAG),46 cases of CAG with IM,34 cases of paracancerous IM and 50 cases ofgastric cancer.The IM was divided into three subtypes by HID-AB staining:27 cases of IM Ⅰ,23 cases of IM Ⅱ,and 30 cases of IM Ⅲ.H.pylori infection was detected with one minute rapid urease test,serum H,pylori IgG of ELISA method and HE staining in 80 caese of IM,which were divided into 46 cases of H.pylori-posi-tive groups and 34 cases of H.pylori-negative groups.Results The positive rates of H.pylori infection in IM Ⅰ,IM Ⅱ andIM Ⅲ were 66.67％,65.22％ and 43.34％,respectively,and there was no significant difference among different subtypes ofIM (x2=3.953,P＞0.05).The positive rates of CDX2 expression in IM Ⅰ,IM Ⅱ and IM Ⅲ were 85.19％,69.57％ and 36.67％,respectively,and IM Ⅲ were significant lower than IM Ⅰ,IM Ⅱ (x2 =13.899,P＜0.001;x2 =5.638,P=0.018),and there was no significant difference between IM Ⅰ and IM Ⅱ.Comparing of different types of IM group and gastric cancer group showed that the positive rates of CDX2 expression in IM Ⅰ,IM] were significant higher than in gastric cancer group (x2 =14.517,P＜0.001;x2 =5.509,P＜0.05),but there was no significant difference between IM Ⅲ and gastric cancer group (x2 =0.088,P＞0.05).The positive rates of CDX2 expression in H.pylori-positive groups was significant higher than in H.pylori-negative groups in all of.IM (76.09％ vs 44.12％,x2 8.525,P=0.004).Comparing between different subtypes of IM showed that the positive rates of CDX2 expression in H.pylori-positive groups was significant higher than in H.pylori-negative groups in IM Ⅲ (P=0.023),but there was no significant difference between IM Ⅰ and IM Ⅱ (P＞0.05).There was also no significant difference of CDX2 expression between H.pylori-positive groups and H.pylori-negative groups in gastric cancer.Conclusion H.pylori infection may affect the progression of IM and gastric carcinogenesis by affecting the expression of CDX2 in different subtypes of IM.

Objective To study the hip angle characteristics in hemiplegic gait.Methods Gait analysis was performed in 20 subjects with hemiplegia and 20 healthy subjects and the hip joint angle of all subjects was analyzed.Results The hip joint angle of affected-side lower limb of hemiplegic gait showed significant differences between 20 subjects with hemiplegia and 20 healthy subjects on hip flextion at heel-contact,maximum extension in stand phase,flextion toe-off,maximum flexion in swing phase and total excursion on sagittal plane.Conclusion The research on the characteristics of hemiplegic gait is helpful to make clinical assessment and treatment planning.

ObjectiveTo study the reliability and sensitivity of the gait analysis system based on digital video and image processing.Methods20 healthy subjects were assessed twice by the same doctor having one-week interval to investigate intraobserver reliability, they were also assessed twice separately by two doctors to investigate interobserver reliability. Gait parameters of affected limb of 20 hemiplegic patients were compared with 20 healthy subjects to investigate the sensitivity of this system.ResultsThere were high correlations in all the parameters between the two assessments. The parameters of the patients were significantly different from those of the controls.ConclusionThe system is sufficiently repeatable and sensitive in the assessment of gait.