Objective:To explore the value of nomogram based on arterial spin labeling (ASL) MRI perfusion parameters and clinicopathological features in predicting the response to chemoradiotherapy (CRT) in advanced nasopharyngeal carcinoma (ANPC, stage Ⅲ and Ⅳ).Methods:From June 2018 to January 2021, 70 patients with ANPC confirmed by pathology were prospectively enrolled in Affiliated Hospital of Jiangnan University. Nasopharyngeal MRI plain scan, ASL and contrast-enhanced scan were performed before CRT, and routine MRI re-examination was performed within 1 week after the end of CRT. The pre-CRT perfusion parameter tumor blood flow (TBF) from ASL and clinicopathological features were recorded, and the maximum diameter (MD) of the tumor on T 1WI images was measured. The patients were divided into CRT effective group (48 cases) and ineffective group (22 cases) according to the response evaluation criteria in solid tumors. The independent sample t test was used to compare the differences of TBF, age and MD between effective group and ineffective group. The χ 2 test was used to compare the differences of gender, clinical stage and pathological type between the 2 groups. Using binary logistic regression analysis, clinicopathological model and TBF combined clinicopathological model were constructed, and the nomogram of combined model was constructed. The diagnostic efficacy of the models was obtained by receiver operating characteristic (ROC) curve analysis, and the area under the ROC curves (AUC) of the 3 models were compared by DeLong method. The calibration curve for the nomogram was generated, and the concordance index (C index) was acquired. Results:The TBF of the effective group and the ineffective group were (113±9) and (97±14) ml·100 g -1·min -1, with a statistical difference ( t=5.17, P<0.001). The MD value of the effective group was smaller than that of the ineffective group, with a statistical difference ( t=-2.24, P=0.028). There were statistical differences in clinical stage and pathological type between the 2 groups (χ 2 values were 12.21 and 12.95, respectively, both P<0.001). Three independent predictors, including TBF (OR=7.749), clinical stage (OR=0.129) and pathological type (OR=5.228), were included in logistic regression analysis. The AUC, sensitivity and specificity of TBF model in predicting the response to CRT were 0.843, 87.5% and 72.7%, of clinicopathological model were 0.822, 80.2% and 59.1%, of the nomogram model were 0.893, 81.2% and 90.9%. There was no statistical difference of AUC between the nomogram model and TBF model ( Z=1.23, P=0.215). However, the AUC of the nomogram model was greater than that of the clinicopathological model ( Z=2.47, P=0.031). The calibration curve showed that there was a good concordance index (C index=0.892) between the predicted value of nomogram and the actual clinical observation value. Conclusion:TBF, clinical stage and pathological type are independent predictors of the response to CRT in ANPC patients, and the nomogram based on these three factors has a good ability in predicting the response to CRT.

Objective:To evaluate the clinical value of 18F-FDG PET/CT findings in patients with T1-2 lung adenocarcinoma spread through air spaces (STAS). Methods:From June 2018 to June 2020, a total of 80 patients (36 males, 44 females; age: 19-84 (59.9±11.8) years) with surgically and pathologically confirmed T1-2 lung adenocarcinomas in Jiangmen Central Hospital were enrolled retrospectively. All patients underwent 18F-FDG PET/CT examination preoperatively and were divided into STAS positive and negative groups according to the histopathological diagnosis. Independent-sample t test, Mann-Whitney U test, χ2 test and Fisher exact test were used to analyze differences of gender, age, tumor biomarker, SUV max, SUV mean, features showed on high resolution CT (HRCT; including diameter, lesion location, morphology, density, lobulated sharp, spiculated sign, vacuole sign, air bronchgram sign, pleural traction and para-emphysema), and pathologic findings (micropapillary pattern, lymphvascular inversion, pleural inversion and lymph node metastasis) between the two groups, and then multivariate logistic regression was performed. The ROC curve was employed to evaluate the predictive value of parameters for STAS of T1-2 lung adenocarcinomas. Results:Among the 80 patients with T1-2 lung adenocarcinomas, 12 (15.0%) were STAS positive and 68 (85.0%) were STAS negative. Significant differences were shown in SUV max, SUV mean, micropapillary pattern, lymphvascular inversion and lymph node metastasis between the two groups ( z values: -2.60, -2.17; χ2 values: 29.56, 9.28, 17.40, P<0.001 or P<0.05). SUV max (odds ratio ( OR): 1.348 (95% CI: 1.071-1.695), P=0.011), micropapillary pattern ( OR=47.444 (95% CI: 4.592-490.214), P=0.001) and lymph node metastasis ( OR=8.201 (95% CI: 1.129-59.576), P=0.038) were independent risk factors for STAS positive in multivariation logistic regression analysis. The optimum cut-off value for SUV max was 3.85 in the ROC analysis with the AUC of 0.737 (95% CI: 0.614-0.859), the sensitivity of 11/12, the specificity of 55.9%(38/68) and the accuracy of 61.2%(49/80). The AUC of the SUV max combined with micropapillary pattern and lymph node metastasis was 0.945 (95% CI: 0.892-0.999) with the sensitivity of 11/12, the specificity of 88.2%(60/68) and the accuracy of 88.7%(71/80). Conclusions:The PET/CT characteristics may be useful in differentiating STAS status among patients with T1-2 lung adenocarcinoma. SUV max >3.85, pathological papillary pattern and lymph node metastasis are independent risk factors to predict STAS.

In this study, through the analysis of the composition of domestic large radioactive medical equipment PET/CT and the characteristics of each subsystem, combing the vulnerable spots, according to the standard requirements of PET/CT for 10 years in its service life, we research the PET/CT service life's effectiveness. Firstly, this study introduces the concept of service life, the relationship between service life and risk analysis, the pivotal system composition of PET/CT, the importance of reliability of each component, the traditional test method to verify its reliability is researched. This study suggests a test procedure and method to prove the reliability of various components of PET/CT equipment during the service life. This method is described in detail, and the specific test process in practical engineering application is discussed, which proves that it is beneficial to ensure the effectiveness of PET/CT during the service life.
Positron Emission Tomography Computed Tomography ; Positron-Emission Tomography ; Reproducibility of Results ; Tomography, X-Ray Computed

Based on the clinical application data of medical X-ray computed tomography (CT) in the Shanghai Sixth People's Hospital, this study transformed it into the product reliability index requirements, and took the mechanical representative component-examination table (hereinafter referred to as "patient table") and the electronic representative component-DCB (data control board) as examples. Based on the relationship between failure characteristics and clinical application data, a complete set of closed-loop implementation methods from reliability index requirements to reliability design and verification are discussed.
China ; Humans ; Reproducibility of Results ; Tomography, X-Ray Computed

In this study, the virtual simulation tutoring system was applied to the teaching of dental residents in the standardized training stage for the first time, including the curriculum preparation, curriculum design and teaching practice. Through the practice of the preparation of class Ⅱ holes and the tooth preparation of PFM (porcelain fused to metal) by the dental residents in the virtual simulation teaching system, the teaching arrangement of three courses as one term was explored. Each course adopted the matching interactive teaching mode. Finally, the transcripts would be given by the virtual simulation teaching system to comment and summarize. This study has laid a foundation for future promotion of virtual simulation teaching system in the standardized training stage of stomatology residents and found a new direction for improving the proficiency and accuracy of residents' clinical operation skills.

Combined with the clinical use condition of MR in use in Shanghai Sixth People's Hospital, MR components are divided into scanning type I and scanning type II. At the same time, combined with the main loss force of MR components, the research divides MR components into dynamic components and electric thermal components. In this study, a complete set of MR system reliability indexes and implementation methods are given, including system reliability index determination, system reliability allocation, component reliability index realization, system reliability prediction and system reliability verification. At the same time, this study also gives the methods of reliability prediction and reliability verification, and gives the MTBF calculation method of MR system based on clinical use data statistics.
China ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Reproducibility of Results

This study mainly discusses the contents, methods and characteristics of the collection of operation and maintenance data, as well as the establishment and evaluation methods of the distribution model of the failure time of medical electrical equipment. The distribution models of failure time at three levels of medical electrical equipment are established by linear regression method and goodness of fit test:The first is the device level MTBF distribution model, the second is the failure rate distribution model of the failure mode of key components, the third is the calculation model of the influence coefficient of influence factor on the failure mode of key components. This study presents a method of establishing MTBF segment model and implements a calculation model of influence coefficient varying with time.
Maintenance

Objective To investigate the specific sites that estrogen receptor (ER)α could be recruited to in the p21WAF1/CIP1 promoter region to regulate its transcriptional activity in MCF-7 cells,and to clarify the molecular mechanism of suberoylanilide hydroxamic acid (SAHA) and leptin in the regulation of p21WAFI/CIP1 promoter function.Methods MCF-7 cells were starved by culturing them in fetal calf serum-free medium for 24 hours,and then treated with 20 μmol/L of 0.88 μL SAHA (SAHA group) or 0.625 nmol/L of 10 μL leptin (leptin group) for 24 hours,or cultured in complete RPMI-1640 medium (control group).Cell lysates were incubated with anti-ERα antibody for ChIP analysis.The relative expression levels of DNA fragments,ranging from the TSS to upstream of the p21WAF1/CIP1 promoter region (+2 to-4 000 bp),that bound the antibody were detected by real-time PCR.Results In the control group,the relative expression levels of f1,f2,and f8 DNA fragments that bound the antiERα antibody were two-fold higher than the relative expression of the f9 fragment (P ＜ 0.01).In the SAHA and leptin groups,the relative expression of f1 to f10 DNA fragment that bound anti-ERα antibody was significantly lower than that of the control.The binding affinity of ERα for the f8 fragment was the lowest (P ＜ 0.01) in the SAHA group,and it was significantly lower than that in the leptin group (P ＜ 0.01).Conclusion ERα could be recruited to the p21WAFI/CIP1 promoter via signaling pathways activated during the proliferation of breast cancer MCF-7 cells.Moreover,the DNA fragment ranging from-2 800 to-3 200 bp upstream of the p21 WAF1/CIP1 promoter is the target functional region for high-affinity binding with ERα.

Aim To investigate the specific binding sites that histone deacetylases 1(HDAC1) and estrogen receptor α(ERα)can be recruited to regulate the transcriptional activity of p21WAF1/CIP1 promoter in the breast cancer MCF-7 cells, and to clarify the molecular mechanism of suberoylanilide hydroxamic acid(SAHA) and leptin regulating p21WAF1/CIP1 promoter function.Methods The breast cancer MCF-7 cells in logarithmic growth phase were starved with FBS free medium for 24 hours, and treated with 20 μmol·L-1 SAHA(SAHA group) or 0.625 nmol·L-1 leptin(Leptin group) for 24 hours.The cells that were cultured in complete RPMI 1640 medium without any treatment were assigned as control group(Basal group).The cell lysis was prepared and incubated respectively with anti-HDAC1 and anti-ERα antibody by chromatin-immunoprecipitation(ChIP) method overnight at 4℃.The DNA-ChIP was followed the manufacturer′s protocol for the assay.DNA fragments binding anti-HDAC1 and anti-ERα antibody were gathered and purified.The relative expression level of DNA fragments from TSS to the upstream of the p21WAF1/CIP1 promoter region(+2~-4 000 bp) binding with antibody was detected by real-time PCR and analyzed by 2-△△CT method.Results In basal group, HDAC1 and ERα had high affinity with the f1 and f8 fragments of p21WAF1/CIP1 promoter compared to the f4 fragment.In SAHA group, the binding ability of HDAC1 and ERα to the f1 and f8 fragments of p21WAF1/CIP1 promoter was significantly lower than that of the control, while reversing to reach the peak after leptin treatment.Conclusions HDAC1 and ERα can be recruited to p21WAF1/CIP1 promoter by the cell proliferation signal during the proliferation of breast cancer MCF-7 cells.The DNA f1(from 0 to-400 bp) and f8(from-2 800 to-3 200 bp) fragment in the upstream of p21WAF1/CIP1 promoter are the target functional region for the binding with HDAC1and ERα.

Aim Toinvestigatethespecificbinding sites that HDAC1 can be recruited to regulate the tran-scriptional activity of p21 WAF1/CIP1 promoter in the breast cancer MCF-7 cells.Methods ThebreastcancerMCF-7 cells in logarithmic growth phase were starved with FBS free medium for 24 hours,and treated with 20 μmol·L-1 SAHA(S group)or 0. 625 nmol·L-1 Leptin(L group)for 24 hours,and the cells that were cultured in the complete RPMI 1640 medium without any treatment were assigned as control group (B group).The DNA-ChIP was followed the manufactur-er′s protocol for the assay.The cell lysis was prepared and incubated with anti-HDAC1 antibody overnight at 4℃.DNA fragments binding anti-HDAC1 antibody were gathered and purified.The relative expression level of DNA fragments from TSS to the upstream of the p21 WAF1/CIP1 promoter region(+2 ~-4000 bp)bind-ing with antibody was detected by Real-time PCR and analyzedby2-ΔΔCTmethod.Results InBgroup, HDAC1 had high affinity with the f1 and f 8 fragmentsof p21 WAF1/CIP1 promoter compared to the other fragemts,and showed the highest affinity with the f8 fragment.In S group,the binding ability of HDAC1 to the f1 ~f10 fragment of p21 WAF1/CIP1 promoter was sig-nificantly lower than that of the control.The binding activity of HDAC1 to f8 fragment was the lowest,while reversing to reach the peak after leptin treatment.Con-clusions HDAC1canberecruitedtop21WAF1/CIP1pro-moter by the cell proliferation signal during the prolifer-ation of breast cancer MCF-7 cells.The DNA fragment from -2800 to -3200 bp in the upstream of p21 WAF1/CIP1 promoter is the target functional region for the binding with HDAC1 .