Objectives To investigate the specific site for measuring inferior alveolar nerve canal (IANC) by cone beam computed tomography (CBCT),and to provide reference data of the course of the IANC of the crowd.Methods This study was a retrospective data analysis.One hundred and thirty CBCT cases were measured and compared after classification by gender and age (65 men and 65 women,65 middle age and 65 youth).Since the proximal center of the mental foramen area,the cross-section at which the mental hole just completely breaks the buccal cortical bone was defined as S1,and S2,S3,S4 were defined as cross-sections with 1-cm apart from each other since S1.L1,L2,L3,and L4 were measured as the distance from specific sites on the outer wall of the IANC to the alveolar crest,the outer wall of lingual lateral cortical bone,the mandibular minimum margin,and the outer wall of buccal cortical bone.The results were analyzed using independent samples t test,with P＜0.05 being considered statistically significant.Results On the right IANC S2L1,S3L1,S4L1,S2L2,S3L2,S4L2,S1L3,S3L4,the 8 groups of L values measured on these 8 sites,all showed differences between genders (P＜0.05).So did the 10 groups of L values measured on the left IANC S1L1,S2L1,S3L1,S4L1,S1L2,S3L2,S4L2,S2L3,S3L3,S4L4 (P＜0.05).The middle age group and the youth group were statistically different for the data measured on the right IANC S2L4 (P＜0.05).This was the same case for the data measured on the left IANC S1L3.When classified according to gender,L1 in the S1 to S4 sections firstly increased and then decreased,and eventually decreased.The change pattern of L3 was opposite to that of L1.L2 in the S1 to S4 sections firstly decreased and then decreased,and eventually increased.The change pattern of L4 was opposite to that of L2.When the samples were classified according to age,the change pattern L value in the S1 to S4 sections was the same as that under gender classification.Conclusions The effect of gender on the L value of individuals is relatively great,while the effect of age on the L value of individuals value is very small.Setting the corresponding long axis of mandible as a reference,the change pattern of IANC in the mandible can be deduced based on the change of L value from S 1 to S4:from S1 to S4,the course of IANC on the vertical direction is firstly downward,tben turns to upward and goes upward;from S1 to S4,the trend of IANC on the horizontal direction is firstly toward the side of tongue,and eventually turns towards the buccal side.The current study provides reference data for IANC-related anatomy from the mandibular foramen to the mandibular second molars.

A rapid method has been developed based on the sample preparation procedure named as QuEChERS (Quick,Easy,Cheap,Effective,Rugged and Safe),combined with reversed-phase high performance liquid chromatography with fluorescence detector and C18 column after precolumn derivatization using o-phthalaldehyde and 2-mercaptoethanol to determine dopamine in porcine muscle.Methanol and deionized water (0.1％ acetic acid,v/v) with a ratio of 60∶40 was used as mobile phase.The flow rate was 0.8 mL/min and dopamine was eluted within 15 min.The linearity range was 0.003-8 μg/mL with r=0.9992.The detection limit for dopamine was 4 μg/kg and the quantification limit was 9 μg/kg.Recovery studies were carried out at 0.1,0.5 and 1.0 mg/kg fortification levels and the average recoveries obtained ranged from 90.4％ to 98.2％ with relative standard deviations between 3.5％ and 8.1％.The method was found to be suitable for detection of dopamine in animal product tissues at the maximum residue level.

A rapid method has been developed based on the sample preparation procedure named as QuEChERS （Quick, Easy, Cheap, Effective, Rugged and Safe）, combined with reversed-phase high performance liquid chromatography with fluorescence detector and C18 column after precolumn derivatization using o-phthalaldehyde and 2-mercaptoethanol to determine dopamine in porcine muscle. Methanol and deionized water （0.1% acetic acid, v/v） with a ratio of 60：40 was used as mobile phase. The flow rate was 0.8 mL/min and dopamine was eluted within 15 min. The linearity range was 0.003-8 μg/mL with r=0.9992. The detection limit for dopamine was 4 μg/kg and the quantification limit was 9 μg/kg. Recovery studies were carried out at 0.1, 0.5 and 1.0 mg/kg fortification levels and the average recoveries obtained ranged from 90.4% to 98.2% with relative standard deviations between 3.5% and 8.1%. The method was found to be suitable for detection of dopamine in animal product tissues at the maximum residue level.

Objective To investigate the effect of the examination mode which focuses on students' comprehensive skill and capability, and then provide some references for the consummation of the examination evaluation system of the course of pathogenic biology and immunology experiments. Methods Students of five-year class of stomatology of Grade 2009 were selected to sit the innovating examination. The evaluation of the effect was analysed by the way of a questionnaire. Results Many students set higher values on the innovating course arrangement and examination mode which improved their capacity of experimental design, operational technique, writing of laboratory reports, innovative ability and so on. Conclusion The innovating course arrangement and examination mode are superior compared to the old one and can improve students comprehensive ability.

To discover novel fluoroquinolone lead compounds as possible anti-infective or/and antitumor chemotherapies, combination principle of pharmacophore-based drug design, a series of novel tricyclic fluoroquinolone title compounds, [1,2,4]triazino[3,4-h][1,8]naphthyridine-8-one-7-carboxylic acid derivatives ( 5a-5p), were designed and synthesized with a fused [1,2,4]-triazine ring unit. Their structures were characterized by spectral data and elemental analysis and the in vitro antibacterial and anti-cell proliferation activities were also evaluated. The results showed that the titled compounds exhibited more significant inhibitory activities against drug-resistant bacteria (Methicillin-resistant Staphylococcus aureus and multi drug-resistant Escherichia coli strains) and three tested cancer cell lines (human hepatoma SMMC-7721, murine leukemia L1210 and human murine leukemia HL60 cells). Interestingly, SAR showed that compounds with electron-donating groups attached to benzene ring had stronger antibacterial activity than antitumor activity, but electron-withdrawing compounds displayed more potential antitumor activity than antibacterial activity, especially antitumor activity of nitro compounds was comparable to comparison doxorubicin. Thus, novel triazine-fused tricyclic fluoroquinolones as potent anti-infective or/and antitumor lead compounds are valuable to pay attention and for further development.

Objective Comparing the effects of steam sterilization on cyclic fatigue of stainless steel files. Meth-ods Fifty instruments of 25# stainless steel K files were randomly divided into 5 groups, which include 10 in each group. Group 1 was the blank control group, group 2 to 5 were subjected to 1, 3, 4, 5 steam sterilization cycles, then the files were tested by a custom-made device to assess cyclic fatigue and the number of cycles of failure (NCF) was calculated. Microstruc-ture of each file’s fracture surface was analyzed by Scanning Electron microscope (SEM). Results NCF in the 5 groups were 4 345.2 ± 384.2,3 937.9 ± 645.4,3 812.9 ± 532.5,3 626.2 ± 380.0,3 625.9 ± 565.6 respectively, and the differences among 5 groups were significantly different(F=2.598, P<0.05). After 4 or 5 times of steam sterilization, cyclic fatigue de-creased if compared with that in control group (P<0.05). Fracture surface in group 1 and group 2 was tough dimple structure and large numbers of regular, deep dimples were distributed on the surface. You could also see micro cavities clearly formed by fracture;Fracture surface in group 4 was dimple structure in brittle intergranular morphology. It is characterized by the presence of thin brittle precipitates, clean and smooth crystal interface, and a great sense of polyhedral stereo. Conclusion After 4 times of steam sterilization, cyclic fatigue strength of 25# stainless steel K files declined, which possessed the poten-tial risk of fracture.

Thyroid hormone is an important hormone for regulating cell differentiation,growth and metabolism.Many studies have shown that thyroid hormone can induce turmor angiogenesis after binding with the integrin ανβ3 receptor at cell surface.Tetraiodothyroacetic acid is the analogue of thyroid hormone,and can inhibit tumor angiogenesis by inhibiting the binding of thyroid hormone with integrin ανβ3.Studying the role of thyroid hormone in promoting tumor angiogenesis may provide a new approach for molecular targeted therapy of tumor.

Objective To investigate the prevalence and spectrum of β-thalassemia mutations in C, uangdong province, and provide a reference for prenatal diagnosis and genetic counseling in this population. Methods Three thousand two hundred and forty-seven blood samples were randomly selected from Guangzhou and 2984 blood samples from Shenzhen from January in 2005 to January in 2009. PCR and reverse dot blot hybridization (RDB) were adopted for detection of β-thalassemia mutations in Guangzhou and Shenzhen city. Results Seven hundred and fifty-one individuals in Guangzhou were found to have β-hemoglobin gene mutations, the detection rate was 23.13%(751/3247); 10 different mutations were identified, namely CD41-42(-TCTT), IVS-Ⅱ-654(C→T), -28(A→G), CDI7(A→T), CD71-72(+A), 13E, IVS-I-1(G→T), CD43(G→T), -29(A→G), CDI4-15(+G), which accounted for 42.53% (336/790) ,25.19% (199/790), 12.66% (100/790), 10.89% (86/790) ,3.29% (26/790), 2.15%(17/790), 1.27%( 10/790), 1.14%(9/790) ,0.51%(4/790) ,0.38%(3/790), respectively; the most common mutation was CD41-42(-TCTT), which accounted for 42.53%(336/790). In Shenzhen, 179 individuals were found to have β-thalassemia mutations, the detection rate was 6.00% (179/2984); 8 different mutations were identified excluding CD43 (G→T) and CD14-15 (+G); the most common mutation, however, was IVS-lI--654(C→T), which accounted for 40.44% (74/183). Conclusions The β-thalassemia mutations in Guangdong province are not only frequent, but also obviously heterogeneous, and the mutations differ from region to region. CD41-42 (-TCTT),ⅣS-Ⅱ-654(C→T), -28(A→G), CD17(A→T) were the 4 predominant mutations.

To explore a new strategy for further optimization to the C-3 bioisteric heterocyclic ring of fluoroquinolones,twelve novel fluoroquinolone C-3 s-triazole Schiff-base carboxylic acid derivatives(7a-71) were designed and synthesized with both functionalized sulfanylacetic acid and Schiff-base moieties as the modified side-chain for the C-3 bioisosteric s-triazole ring of pefloxacin(1).The structures were characterized by elemental analysis and spectral data,and the in vitro anti-tumor activity of the title compounds against SMMC-7721,L1210 and HL60 cell lines was evaluated.The preliminary pharmacological results demonstrated that the title compounds possessed more significantly anti-proliferative activity than either the parent 1 or the corresponding amine intermediates(6).In particular,the title compound bearing a fluorine atom (7j) and compound bearing a nitro group attached to benzene ring (71) were comparable to the control doxorubicin against SMMC-7721 cells with an IC50 value of micro-molar concentration,respectively.It suggests that s-triazole ring modified with functional side-chain moieties instead of the C-3 carboxylic group is favorable to the improvement of antitumor activity.

Objective To study the meaning of breast cancer staging system by AJCC eighth edition to invasive lobular carcinoma and analysis the clinical pathological characteristics.Methods According to the eighth edition of the AJCC staging to evaluate the TNM stage and prognosis evaluation of invasive lobular carcinoma cancer patient in Peking University Shenzhen Hospital from 2011 to 2016,and compared with others in clinical pathological data.Results There were 21 cases of invasive lobular carcinoma,accounting for 2.7％ of all invasive breast cancer.We found that invasive lobular carcinoma shows no significant difference (P ＞ 0.05) in ages,menstrual status,molecular features and anatomic staging and prognosis staging with others;histological grade were significantly different (P ＜ 0.05).There were significant differences in the prognosis and staging of invasive lobular carcinoma.Conclusions Eighth AJCC staging systemn provides a new reference for the clinical treatment of breast cancer,should be evaluated with anatomic stage.Histological grade is relatively good in invasive lobular carcinoma and the prognosis is good,needs more research to the individualized treatment of invasive lobular carcinoma.