Objective:To assess the repeatability ( intraobserver comparison ) and reproducibility ( inter-observer comparison) of two different methods for establishing the occlusal plane on digital dental models. Methods:With Angle’ s classification as a stratification factor,48 cases were randomly extracted from 806 ones which had integrated clinical data and had their orthodontic treatment from July 2004 to August 2008 in Department of Orthodontics,Peking University School and Hospital of Stomatology. Post-treatment plas-ter casts of 48 cases were scanned by Roland LPX-1200 3 D laser scanner to generate geometry data as re-search subjects. In a locally developed software package,one observer repeated 5 times at intervals of at least one week to localize prescriptive landmarks on each digital model to establish a group of functional occlusal planes and a group of anatomic occlusal planes, while 6 observers established two other groups of functional and anatomic occlusal planes independently. Standard deviations of dihedral angles of each group on each model were calculated and compared between the related groups. The models with the five largest standard deviations of each group were studied to explore possible factors that might influence the identification of the landmarks on the digital models. Results:Significant difference of intraobserver varia-bility was not detected between the functional occlusal plane and the anatomic occlusal plane ( P>0 . 1 ) , while that of interobserver variability was detected ( P<0 . 001 ) . The pooled experimental standard devia-tion the 6 observers established for the functional occlusal plane was 0 . 2 ° smaller than that of the anato-mic occlusal plane. The functional occlusal plane’ s variability of intraobserver and interobsever did not differ significantly (P>0. 1),while the anatomic occlusal plane’s variability of the intraobserver was sig-nificantly smaller than that of the interobserver (P<0. 001),with a 0. 12° difference value of the pooled experimental standard deviation. Conclusion: When one observer measures a number of digital models, both the functional and the anatomic occlusal planes are suitable as a conference plane with equal repeatability. When several observers measure a large number of digital models,the functional occlusal plane is more reproducible than the anatomic occlusal plane,but the difference is small.

Objective To study the anatomic landmarks of recurrent laryngeal nerve (RLN) in minimally invasive video-assisted thyroidectomy (MIVAT), and to evaluate the operative skills to avoid nerve injury. Methods 106 patients were enrolled in the study dated between August 2008 and August 2010, in which 8 patients were converted to the conventional thyroidectomy. Intraoperative anatomic landmarks for location of RLN were the gap between trachea and carotid artery (GTC), as well as the middle and posterior portion of tracheal wall. Results 98 RLN were at risk, and 97 (98.98 %) nerves were recognized by means of two landmarks. 1 nerve failed to locate which was non-recurrent laryngeal nerve. Temporary RLN paralysis happened to 1 nerve(1.02 %), and no permanent RLN paralysis appeared. Conclusion GTC combined with middle and posterior portion of tracheal wall are safe and effective anatomic landmarks to locate RLN in MIVAT.

Objective To study the rule of lymph node metastasis rate in cN 0 papillary thyroid microcar-cinoma( cN0-PTMC) and to evaluate an appropriate region of neck dissection .Methods Data of 233 cases of cN0-PTMC were retrospectively analyzed .Univariate analysis with chi-square test was used to analyze the statisti-cal correlation between gender , age, tumor diameter and lymph node metastasis respectively .Results 81 out of 233 patients(34.8%)had cervical lymph node metastasis (30.0%in central region and 9.9%in lateral region). For patients with tumor diameter ( D)≤5 mm and D>5 mm, lymph node metastasis rate in central region was 21.6%and 36.6%(χ2 =6.199,P<0.05) and it was 4.9% and 13.7% respectively in lateral region (χ2 =5.035,P<0.05).For male and female patients, lymph node metastasis rate in central region was 42.1% and 26.1%respectively(χ2 =5.224,P<0.05), and it was 21.1% and 6.3% respectively in lateral region (χ2 =10.604,P<0.01).Lymph node metastasis rate in patients≤45 years old and >45 years old was 37.9% and 21.1% respectively (χ2 =7.792, P <0.01 ) .The lateral region lymph node metastasis rate was 17.1% and 6.7%when the central region lymph node was infringed or not (χ2 =5.947, P<0.05).Conclusions All cN0-PTMC patients should have a normative central neck dissection .Male patients with PTMC and tumor diameter >5 mm should receive the lateral neck lymphoid tissue exploration during surgery in order to find subclinical metas -tasis.

ObjectiveTo discuss the expression of VEGF and COX-2 in breast cancer and their correlation with Clinical relationships.MethodsWith Elivision immunohistochemistry,the expression of VEGF and COX-2 was evaluated in 60 samples with primary breast cancer,and it was determined that the correlation of their expression and the clinical features including age,tumor size,clinical TNM staging,pathological grading,armpit lymph node metastasis and prognosis. ResultsThe expression of VEGF had close correlation with tumor size, the clinical TNM staging, pathological grading, and armpit lymph node metastasis (P ＜0.05),but had no correlation with age.The expression of COX-2 had close correlation with the clinical TNM staging pathological grading, and armpit lymph node metastasis (P ＜0.05), but had no correlation with age and tumor size. The expression of VEGF had positive correlation with that of COX-2 (r =0.2615, P ＜0.05);In the death group, the expression of VEGF and COX-2 was significantly higher than the survival group (P ＜0.05).ConclusionThe up-regulated expression of VEGF and COX-2 closely correlated with tumor take place, evolution, metastasis and soake of breast carcinoma. The expression of COX-2 had positive correlation with that of VEGF.Combined detection would be helpful in screening the patients of breast cancer with high risks of recurrence and metastasis, judge the prognosis, so it is good for further treatment.

Aim To investigate the anticancer effect of a new xanthono-pyridine derivative N, N '-( 7-oxo-7H-chromeno[3,2-h] quinoline-5,9-diyl)-bis(2-( pyrroli-din-1-yl)acetamide) (XP-16) on human lung carcino-ma cell line A549 and the potential mechanism. Meth-ods Antiproliferative effect of XP-16 on A549 cells was evaluated by MTT assay, morphological examina-tion and colonial assay. Apoptosis detection was car-ried out using Hoechst 33258 and PI double-dyeing method. Intracellular Ca2+ concentration ( [ Ca2+] i ) and mitochondria membrane potential were detected by fluorospectrophotometer. A549 cells treated with XP-16 were collected for Bad and metallothionein 1 A ( MT-1 A ) transcript analysis by real-time reverse tran-scriptase-polymerase chain reaction ( qRT-PCR) . Re-sults XP-16 inhibited A549 cell proliferation in dose-and time-dependent manner. Typical apoptotic mor-
phology such as chromatin aggregation and nuclear fragmentation was observed in A549 cells treated with XP-16 for 24 h, and the apoptosis was showed in a dose-dependent manner. After treated with XP-16, [ Ca2+] i and mitochondria membrane potential of A549 cells were decreased, and relative mRNA level of Bad and MT-1A was up-regulated. Conclusions XP-16 has anticancer effect on A549 cells through apoptosis, which might be associated with decreasing intracellular Ca2+ concentration and mitochondria membrane poten-tial. Up-regulation of MT-1A expression might be the result of decreased [ Ca2+] i .

OBJECTIVE: Through preoperative temporary balloon occlusion of internal carotid artery and monitoring of carotid artery stump pressure variation, in order to further predict the risk of carotid artery ligation and resection, evaluation operative risk and provides the reference for the choice of surgical approach. METHOD: Continuous monitoring and recording the carotid artery stump return pressure,before clamping and in the process of blocking, close observation the patients mental state and the nervous systemof all kinds of signs, in the process of blocking, to understand the dynamic change of stump artery pressure return in patients and whether can the smooth passage of carotid artery balloon occlusion test. RESULT: Of the 19 patients, 4 cases were positive, 15 negative cases, Blocking immediate the positive patients and negative patients with stump pressure drop was (57. 35 ± 1. 89) % and (38. 99 ± 12. 23) %, with statistical significance between the two, in the process of blocking, the mean stump pressure of the positive patients and the negative patients was (37. 29 ± 3. 15) mmHg and (61. 36 ± 14. 69) mmHg, with statistical significance between the two. CONCLUSION Approximately 21. 05% of patients can not tolerate carotid artery balloon occlusion test, theory for carotid artery reconstruction operation. After blocking the stump pressure is less than 40. 44 mmHg, the theory for reconstruction of the internal carotid artery operation. Blocking instant artery stump pressure dropped more than 55. 46%, in theory the need for internal carotid artery reconstruction.
Balloon Occlusion ; Blood Pressure ; Carotid Artery, Internal ; surgery ; Feasibility Studies ; Humans ; Ligation ; Preoperative Care ; Risk Assessment ; Vascular Surgical Procedures

Objective This study aims to predict the coronavirus disease 2019(COVID-19)epidemic in Xi'an based on SEAIQR model and Dropout-LSTM model,and to provide a scientific basis for evaluating the effectiveness of the"dynamic zero-COVID policy".Methods Considering a large number of asymptomatic infections,the changing parameters,and control procedures,we developed a time-dependent susceptible-exposed-asymptomatic-infected-quarantined-removed(SEAIQR)model with stage-specific interventions.Considering the time-series characteristics of COVID-19 data and the nonlinear relationship between them,we constructed a deep learning Dropout-LSTM model.The data of newly confirmed cases in Xi'an from December 9th,2021 to January 31st,2022 were used to fit the model,and the data from February 1st,2022 to February 7th,2022 were used to evaluate the model performance of forecasting.We then calculated the effective reproduction number(Rt)and analyzed the sensitivity of the different measurement scenarios.Results The peak of newly confirmed cases predicted by the SEAIQR model would appear on December 26th,2021,with 176 cases,and the"dynamic zero-COVID policy"may be achieved in January 24th,2022,with R2=0.849.The Dropout-LSTM model can reflect the time-series and nonlinear characteristics of the data,and the predicted newly confirmed cases were highly consistent with the actual situation,with R2=0.937.The MAE and RMSE of the Dropout-LSTM model were lower than those of the SEAIQR model,indicating that the predicted results were more ideal.At the beginning of the outbreak,R0 was 5.63.Since the implementation of comprehensive control,Rt has shown a gradual downward trend,dropping to below 1.0 on December 27th,2021.With the reduction of effective contact rate,the early implementation of control measures and the improvement of immunity threshold,the peak of newly confirmed cases will continue to decrease.Conclusion The proposed Dropout-LSTM model forecasts the epidemic well,which can provide a reference for decision-making of the"dynamic zero-COVID policy."

Objective To explore the correlation between 18F-NaF micro-PET/CT,μCT score and histopathology of collagen-induced arthritis (CIA) rats.Methods Seventy healthy female SD rats were randomized into CIA group (n＝50) and control group (n ＝ 20).Micro-PET/CT imaging was performed 10 days after successful modeling.Minimum standardized uptake value (SUVmin),maximum standardized uptake value (SUVmax),mean standardized uptake value (SUVmean) and μCT score were measured,and the severity of rheumatoid arthritis was assessed with histopathology.The correlations between SUVmin,SUVmax,SUV μCT score and histopathology of CIA were analyzed.Results SUVmin,SUVmax,SUVmean,μCT score of CIA all showed positive correlations with histopathology (r＝ 0.920,0.943,0.923,0.768,all P＜0.001).Conclusion 18F-NaF micro-PET/CT is a quantitative imaging method for evaluating bone erosion and bone malformation in rat rheumatoid arthritis models of CIA,which is superior to μCT examination.

Objective:To investigate the influencing factors of recurrence after radical resection of middle and low rectal cancer, and to establish a prediction model based on magnetic resonance imaging (MRI) measurement of perirectal fat content and investigate its application value.Methods:The retrospective cohort study was constructed. The clinicopathological data of 254 patients with middle and low rectal cancer who were admitted to Tianjin Union Medical Center from December 2016 to December 2021 were collected. There were 188 males and 66 females, aged (61±9)years. All patients underwent radical resection of rectal cancer and routine pelvic MRI examina-tion. Observation indicators: (1) follow-up and quantitative measurement of perirectal fat content; (2) factors influencing tumor recurrence after radical resection of middle and low rectal cancer; (3) construction and evaluation of the nomogram prediction model of tumor recurrence after radical resection of middle and low rectal cancer. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M(rang) and M( Q1, Q2). Count data were described as absolute numbers. Univariate and multivariate analyses were conducted using the COX regression model. The rms software package (4.1.3 version) was used to construct the nomogram and calibration curve. The survival software package (4.1.3 version) was used to calculate the C-index. The ggDCA software package (4.1.3 version) was used for decision curve analysis. Results:(1) Follow-up and quantitative measurement of perirectal fat content. All 254 patients were followed up for 41.0(range, 1.0?59.0)months after surgery. During the follow-up period, there were 81 patients undergoing tumor recurrence with the time to tumor recurrence as 15.0(range, 1.0?43.0)months, and there were 173 patients without tumor recurrence. The preoperative rectal mesangial fascia envelope volume, preoperative rectal mesangial fat area, preoperative rectal posterior mesangial thickness were 159.1(68.6,266.5)cm3, 17.0(5.1,34.4)cm2, 1.2(0.4,3.2)cm in the 81 patients with tumor recurrence, and 178.5(100.1,310.1)cm3, 19.8(5.3,40.2)cm2 and 1.6(0.3,3.7)cm in the 173 patients without tumor recurrence. (2) Factors influencing tumor recurrence after radical resection of middle and low rectal cancer. Results of multivariate analysis showed that poorly differentiated tumor, tumor pathological N staging as N1?N2 stage, rectal posterior mesangial thickness ≤1.43 cm, magnetic resonance extra mural vascular invasion, tumor invasion surrounding structures were independent risk factors of tumor recurrence after radical resection of middle and low rectal cancer ( hazard ratio=1.64, 2.20, 3.19, 1.69, 4.20, 95% confidence interval as 1.03?2.61, 1.29?3.74, 1.78?5.71, 1.02?2.81, 2.05?8.63, P<0.05). (3) Construction and evaluation of the nomogram prediction model of tumor recurrence after radical resection of middle and low rectal cancer. Based on the results of multivariate analysis, the tumor differentiation, tumor pathological N staging, rectal posterior mesangial thickness, magnetic resonance extra mural vascular invasion, tumor invasion surrounding structures were included to construct the nomogram predic-tion model of tumor recurrence after radical resection of middle and low rectal cancer. The total score of these index in the nomogram prediction model corresponded to the probability of post-operative tumor recurrence. The C-index of the nomogram was 0.80, indicating that the prediction model with good prediction accuracy. Results of calibration curve showed that the nomogram prediction model with good prediction ability. Results of decision curve showed that the prediction probability threshold range was wide when the nomogram prediction model had obvious net benefit rate, and the model had good clinical practicability. Conclusions:Poorly differentiated tumor, tumor pathological N staging as N1?N2 stage, rectal posterior mesangial thickness ≤1.43 cm, magnetic resonance extra mural vascular invasion, tumor invasion surrounding structures are independent risk factors of tumor recurrence after radical resection of middle and low rectal cancer. Nomogram prediction model based on MRI measurement of perirectal fat content can effectively predict the probability of postoperative tumor recurrence.