Aim To investigate the effect and mecha-nism of quercetin combined with cisplatin on prolifera-tion and apoptosis of human osteosarcoma cell line MG-63 . Methods MG-63 cells were treated with quercetin alone or combined with cisplatin. Cellular morphologic changes were observed under inverted phase contrast microscope. The effects of proliferation inhibition were assayed by CCK-8 method. The combination effect was judged through Chou-Talaly analysis. The apoptosis ra-tios of cells were analyzed by flow cytometry. The gene expression of Bcl-2 and caspase-3 was detected by RT-PCR assay. The protein expression of Bcl-2 and caspase-3 was measured by Western blot assay. Re-sults Quercetin alone or combined with cisplatin could inhibit the proliferation, but induce the apoptosis of MG-63 cells. Combination of quercetin and cisplatin revealed a synergistic effect on cell proliferation and apoptosis as it reduced the expression of Bcl-2 but en-hanced that of caspase-3 at both gene and protein lev-els. Conclusion Synergistic effect of quercetin com-bined with cisplatin on cell proliferation and apoptosis of MG-63 cells is possibly due to reduction of Bcl-2 and enhancement of caspase-3 expression.

Objective To construct an objective analysis system of corneal nerve tortuosity and detect the changes of corneal subbasal nerve tortuosity in patients with dry eye and diabetes. Methods GradeⅠtoⅣnerve tortuosity were evaluated and 80 photos of each grade were randomly chosen from the in vivo confocal microscopy library. Nerve fibers were extracted,segmented and then analyzed by 6 tortuosity related parameters including L C, Seg L C mean,Cur mean,Specific p,ICM and SCC mean. After verifying the validaty of parameters above,a cross-sectional study was conducted. Subjects were collected from June,2018 to February,2019 in Peking University Third Hospital,and were divided into healthy control group (28 persons 56 eyes),dry eye without diabetes group (28 patients 56 eyes),diabetes without dry eye group(24 patients 48 eyes),diabetes with dry eye group (23 patients 46 eyes) . Basic and dry eye information includes sex,age,ocular surface disease index ( OSDI) ,tear film break-up time (TBUT),Schirmer Ⅰ test (SⅠt) and corneal fluorescence staining (CFS) score. Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) were detected in diabetic patients. Cochet-Bonnet examination (C-BE) was detected to evaluate corneal sensation and 2 corneal subbasal nerve photos of each eye were selected for effective tortuosity and density related parameters analysis. Data was analyzed by SPSS and diagnostic test were perfomed by MedCalc. This study followed the Declaration of Helsinki. This study protocol was approved by Ethic Committee of Peking University Third Hospital ( No. IRB00006761-M2017354 ) . Written informed consent was obtained from each subject prior to entering study cohort. Results L C,Seg L C mean,Cur mean,Specific p,ICM and SCC mean increased as the nerve tortuosity increased from Grade Ⅰ to Grade Ⅳ,with an overall significance among 4 groups (F=39. 100, 36. 367,57. 743,4. 043,6. 818,33. 493;all at P<0. 01). Among the above 6 parameters,Cur mean and L C of any two groups were of significant difference (all at P<0. 01). Twenty three to twenty eight persons were enrolled in each group of the cross-sectional study. Sex and age were comparable among 4 groups. Diagnostic criteria were met in dry eye and diabetes. Corneal sensation parameter C-BE decreased in diabetes without dry eye group and diabetes with dry eye group compared with healthy control group ( all at Adj P<0. 05 ) , other than in dry eye without diabetes group (AdjP≥0. 05). Nerve density of diabetes without dry eye group and diabetes with dry eye group was lower compared with healthy control group(all at P<0. 001),while no significant difference between dry eye without diabetes group and healthy control group(P≥0. 05). Among the effective parameters of tortuosity,L C,Cur mean,Seg L C mean and SCC mean of dry eye without diabetes group,diabetes without dry eye group,diabetes with dry eye group were higher compared with healthy control group ( all at P<0. 05 ) . Diagnostic tests of tortuosity related parameters all showed an area under curve (AUC) from 0. 5 to 0. 7. Conclusions L C and Cur mean can be used to analyze corneal nerve curvature more reliably. Compared with normal volunteers,patients of dry eye or diabetes show higher corneal subbasal nerve tortuosity.

Objective:To compare magnetic resonance imaging (MRI)-based and computed tomography (CT)-based target volume delineation and dose coverage in partial breast irradiation (PBI) for patients with breast cancer, aiming to explore the application value of MRI localization in PBI after breast-conserving surgery.Methods:Twenty-nine patients with early breast cancer underwent simulating CT and MRI scans in a supine position. The cavity visualization score (CVS) of tumor bed (TB) was evaluated. The TB, clinical target volume (CTV), planning target volume (PTV) were delineated on CT and MRI images, and then statistically compared. Conformity indices (CI) between CT- and MRI-defined target volumes were calculated. PBI treatment plan of 40 Gy in 10 fractions was designed based on PTV-CT, and the dose coverage for PTV-MRI was evaluated.Results:The CVS on CT and MRI images was 2.97±1.40 vs. 3.10±1.40( P=0.408). The volumes of TB, CTV, PTV on MRI were significantly larger than those on CT, (24.48±16.60) cm 3vs. (38.00±19.77) cm 3, (126.76±56.81) cm 3vs. (168.42±70.54) cm 3, (216.63±81.99) cm 3vs. (279.24±101.55) cm 3, respectively, whereas the increasing percentage of CTV and PTV were significantly smaller than those of TB. The CI between CT-based and MRI-based TB, CTV, PTV were 0.43±0.13, 0.66±0.11, 0.70±0.09( P<0.001), respectively. The median percentage of PTV-MRI receiving 40 Gy dose was 81.9%(62.3% to 92.4%), significantly lower than 95.6%(95.0%~97.5%) of PTV-CT. Conclusions:The CVS between CT and MRI is not significantly different, but the MRI-based TB, CTV, PTV are significantly larger than CT-based values. The PTV-MRI is of underdose if PBI treatment plan is designed for PTV-CT. As a supplement of CT scan, MRI can enhance the accuracy of TB delineation after breast-onserving surgery.

BackgroundCompared with absenteeism， health-related productivity loss has a long-lasting negative effect， and poses a greater harm and loss. The health-related productivity loss is mediated by self-efficacy， and perceived social support has been shown to have an impact on health-related productivity loss， whereas the interaction mechanism among the three remains unclear. ObjectiveTo investigate the status of perceived social support， occupational coping self-efficacy and health-related productivity loss among ICU nurses， and to test the mediation role of perceived social support in the relationship between occupational coping self-efficacy and health-related productivity loss. MethodsFrom September to November， 2021， purposive sampling technique was adopted to select 468 ICU nurses in 8 tertiary hospitals in Sichuan Province. Subjects were assessed using self-made general information questionnaire， Perceived Social Support Scale （PSSS）， Occupational Coping Self Efficacy Scale for Nurses （OCSE-N） and Stanford Presenteeism Scale-6 （SPS-6）. Pearson correlation analysis was used to examine the correlation among variables. Amos 24.0 was utilized to test the mediation role of perceived social support in the relationship between occupational coping self-efficacy and health-related productivity loss. ResultsA total of 415 ICU nurses completed the valid questionnaire survey. ICU nurses scored （63.13±11.62） on PSSS， （22.24±6.15） on OCSE-N， and （16.83±4.24） on SPS-6. Health-related productivity loss was detected in 279 ICU nurses （67.23%）. Correlation analysis denoted that PSSS total score was positively correlated with OCSE-N total score （r=0.348， P<0.05）， and negatively correlated with SPS-6 total score （r=-0.274， P<0.05）. OCSE-N total score was negatively correlated with SPS-6 total score （r=-0.421， P<0.05）. The direct effect value of occupational coping self-efficacy on health-related productivity loss was -0.401， and perceived social support showed a mediation role in the relationship between occupational coping self-efficacy and health-related productivity loss （the indirect effect value was -0.052， accounting for 11.48% of the total effect）. ConclusionThe occupational coping self-efficacy of ICU nurses may affect the health-related productivity loss through the action path of perceived social support.［Funded by Scientific Research Project of Sichuan Provincial Health Commission （number， 19PJ042）］