OBJECTIVE To establish a interview outline design process and quality control evaluation method based on grounded theory， providing ideas for qualitative research interview outline design in medical fields. METHODS A literature review was conducted to understand the current research status； a preliminary interview outline was developed around the research content. The triangulation method， group evaluation， expert review and pre-interview were adopted to execute the interview outline and conduct quality control. The evaluation indicators and target values were formulated （an average score for the overall quality evaluation of all indicators ≥4.5， and an average score for individual indicators ≥4.00） to evaluate the effect of the interview outline. Taking the research on the mechanism of physicians’ prescribing behavior under the background of Diagnosis Related Groups （DRGs） payment as an example， the methodological contents of above interview outline were applied in practical research. RESULTS The interview outline included basic information and interview questions. The interview questions were divided into three parts：influencing factors survey， promoting and hindering factors of standardizing physician prescription behavior， and communication， with a total of 12 questions. After being reviewed by members of the research group， experts review and pre- interview， a total of 9 people participated in the quality control evaluation of the interview outline. The overall evaluation score was 4.94 （＞4.50）， and the average score of each indicator was greater than 4.00， indicating that the quality of the outline met the requirements for the interview and could be used for the formal interview. CONCLUSIONS The established interview outline design and quality control method based on grounded theory provides ideas for the qualitative research interview outline design in the medical field， and lays the foundation for further using grounded theory to study the influencing factors and mechanisms of physician prescription behavior under the DRG background.

Objective To understand the relationship between air pollutants and digestive system cancers, and to provide a reference for future research and prevention and control of digestive system cancer. Methods All relevant literature published in English between 1970-2022 was searched through the databases of PubMed, web of science and Embase, and meta-analysis was used to explore the effects of specific air pollutants on digestive system cancers. Results PM_2.5 was able to increase the risk of incidence or mortality of total digestive cancers by 11% (1.05 to 1.17). For specific cancers, PM_2.5 was only associated with an increased risk of liver cancer in this study, with a combined RR (95% CI) of 1.31 (1.19 to 1.46), while there was no statistically significant association with other specific digestive cancers ( P>0.05）. NO2 increased the risk of incidence or mortality of total digestive cancers by 3% (1.00 to 1.07). Conclusion For specific digestive system cancers, PM_2.5 has the most pronounced effect on liver cancer. More evidence is needed to support the relationship between NO₂ and cancer. Currently, it has been observed that NO2 has a negative effect on overall digestive cancers. This study provides insights for the prevention and control of digestive system cancer in countries and regions with high PM_2.5 and NO₂ concentrations.

Objective:To investigate the value of detection of cell-free fetal DNA in maternal peripheral blood for Down's syndrome screening.Methods:A total of 1667 pregnant women who were at a higher risk of having a baby with Down's syndrome who received Down's syndrome screening in the First People's Hospital of Datong between January 2020 and March 2021 were prospectively analyzed. After detection of cell-free fetal DNA in maternal peripheral blood, pregnant women who were at a higher risk of having a baby with Down's syndrome decided whether to accept amniocentesis for fetal karyotype. Then follow-up was performed for collecting related information. Finally, detection results of cell-free fetal DNA in maternal peripheral blood, fetal karyotype results and pregnancy outcomes were analyzed.Results:The positive predictive value of detecting cell-free fetal DNA in maternal peripheral blood for trisomy 21, trisomy 18, and trisomy 13 and chromosome abnormality were 100.0%, 100.0%, 0.0% and 66.7%, respectively. The sensitivity and total specificity of detecting cell-free fetal DNA in maternal peripheral blood were 100.0% and 99.8%, respectively. The false positive rate of detecting cell-free fetal DNA in maternal peripheral blood for trisomy 13 and chromosome abnormality was 0.12% and 0.06%, respectively.Conclusion:A high degree of coincidence between detection results of cell-free fetal DNA in maternal peripheral blood and fetal karyotype results can be used as a prenatal screening for Down's syndrome. This has certain guiding significance for invasive prenatal diagnosis through amniocentesis-based fetal karyotype analysis.

Curcumin is a plant-derived polyphenol extracted from the rhizome of turmeric. As curcumin has such favorable properties as anti-inflammation, anti-oxidation, anti-angiogenesis, immune regulation, anti-bacterial and pro-apoptosis and showed few side effects, the application of curcumin in prevention and treatment of periodontal diseases is promising. This article reviewed the research progress of curcumin in the prevention and treatment of periodontitis.

Objective: To investigate different Er:YAG laser power settings on the bonding properties of IPS e.max CAD ceramics. Methods : 96 IPS e.max CAD ceramics blocks (5 mm × 5 mm × 5 mm) were prepared and randomly divided into 8 groups (n = 12), the untreated blocks served as the control, while one of the experimental groups was treated with 4.5% HF for 20 seconds, six remaining test group (C、D、E、F、G、H) were treated with different Er: YAG laser power settings: 100 mJ、200 mJ、300 mJ、400 mJ、500 mJ and 600 mJ. Morphology of the ceramic surface was observed by atomic force microscopy and its shear bond strength (SBS) was tested. Results : Higher shear bond strength values were found in group C-H compared to group B, the highest is group F (24.12 ± 1.91) MPa. The difference was statistically significant. The atomic force microscope observation of the surface structure showed that the control group was smooth and flat, and the HF-like etching group formed a uniform needle-like convex structure. The laser group gradually formed a regularly arranged cylindrical convex structure, in which the surface of the G and H groups was damaged. Conclusion The Er: YAG laser power settings of 400 mJ can be used as an effective pretreatment method before bonding of IPS e.max CAD ceramic.

Objective To learn the overall results of the final test paper in nursing undergraduates of Peking Union Medical College, and to provide the theoretical support for teaching quality assessment of nursing undergraduates.Methods The difficulty coefficient, the discrimination index, the reliability (Cronbach α coefficient) and the degree of coverage were analyzed based on education measurement and education statistical methods.Results The mean total score was 67.8±12.5, ranged from 38 to 95.The difficulty coefficient, the discrimination index and the Cronbach α coefficient were 0.68, 0.30 and 0.71 respectively.The rates of loss score were 33.8% for choice questions, 37.2% for completion questions, 22.5%for true or false questions and 24.8% for calculation questions respectively.Among the total 30 examination questions, the proportions of the most difficult ones, the difficult ones, the moderate ones, the easy ones and the easiest ones were 30.0%,13.3%,20.0%,20.0% and 16.7% respectively.28 examination questions (93.3%) had the best or better discrimination.Conclusions The test paper held the moderate difficulty and the good discrimination, reliability and the degree of coverage.The results of the examination accurately reflect the knowledge and ability of the students.In addition, more attention should be paidto improve the knowledge of nursing undergraduates on the importance of the medical statistics in medical scientific research.

Background:Mortality outcomes in trials of low-dose computed tomography (CT) screening for lung cancer are inconsistent.This study aimed to evaluate whether CT screening in urban areas of China could reduce lung cancer mortality and to investigate the factors that associate with the screening effect.Methods:A decision tree model with three scenarios (low-dose CT screening,chest X-ray screening,and no screening) was developed to compare screening results in a simulated Chinese urban cohort (100,000 smokers aged 45-80 years).Data of participant characteristics were obtained from national registries and epidemiological surveys for estimating lung cancer prevalence.The selection of other tree variables such as sensitivities and specificities of low-dose CT and chest X-ray screening were based on literature research.Differences in lung cancer mortality (primary outcome),false diagnoses,and deaths due to false diagnosis were calculated.Sensitivity analyses were performed to identify the factors that associate with the screening results and to ascertain worst and optimal screening effects considering possible ranges of the variables.Results:Among the 100,000 subjects,there were 448,541,and 591 lung cancer deaths in the low-dose CT,chest X-ray,and no screening scenarios,respectively (17.2％ reduction in low-dose CT screening over chest X-ray screening and 24.2％ over no screening).The costs of the two screening scenarios were 9387 and 2497 false diagnoses and 7 and 2 deaths due to false diagnosis among the 100,000 persons,respectively.The factors that most influenced death reduction with low-dose CT screening over no screening were lung cancer prevalence in the screened cohort,low dose CT sensitivity,and proportion of early-stage cancers among low-dose CT detected lung cancers.Considering all possibilities,reduction in deaths (relative numbers) with low-dose CT screening in the worst and optimal cases were 16 (5.4％) and 288 (40.2％) over no screening,respectively.Conclusions:In terms of mortality outcomes,our findings favor conducting low-dose CT screening in urban China.However,approaches to reducing false diagnoses and optimizing important screening conditions such as enrollment criteria for screening are highly needed.

Objective To analyze the value of plane QRS-T angle on prediction of malignant ventricular arrhythmia (MVA) occurred after emergency percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI). Methods The clinical data of 418 patients with STEMI who underwent PCI within 12 h of symptom onset were retrospectively analyzed, and the patients were divided into plane QRS-T angle ≤ 90° group (324 cases) and plane QRS-T angle>90° group (94 cases) according to the plane QRS-T angle after PCI. The clinical data were compared between 2 groups. Results Compared with patients in plane QRS-T angle ≤ 90° group, patients in plane QRS-T angle > 90° group was older: (67.4 ± 11.8) years vs. (63.6 ± 12.0) years, QTc interval was longer: (438.60 ± 34.97) ms vs. (425.24 ± 25.49) ms, rate of left ventricular ejection fraction (LVEF) <45% was higher: 57.4% (54/94) vs. 35.8% (116/324), rate of using of beta-blockers was less: 74.5% (70/94) vs. 84.9% (275/324), but the incidences of hypertension and MVA were higher:79.8%(75/94) vs. 64.5%(209/324) and 10.6%(10/94) vs. 1.2%(4/324), and there were statistical differences (P<0.01 or<0.05). Logistic regression analysis showed that plane QRS-T angle >90° was an independent risk factor of MVA after PCI in STEMI patients (OR = 9.640, P =0.001), and using of beta-blockers was a protective factor (OR = 0.266, P = 0.028). Conclusions Plane QRS-T angle>90° is an independent risk factor of MVA after PCI in STEMI patients, while the use of beta-blockers is a protective factor. Paients with STEMI after PCI should be alert to the occurrence of MVA in the condition of plane QRS-T angle>90° and not taking beta-blockers.

Objective To explore the medication rules of national TCM masters’ treatment for phymatosis. Methods The prescriptions for phymatosis of national TCM masters were collected to build a database. The methods of association rules with apriori algorithm and complex system entropy cluster were used to achieve frequency of individual herbs, frequency of medicine combinations, association rules of herbs and core medicine combinations. Results In the prescriptions for phymatosis, Chinese medicinal herbs with the highest frequency were Astragali Radix, Pinelliae Rhizoma, Poria, Herba Oldenlandiae, Rehmanniae Radix Exsiccata, and so on. Medicine combinations with the highest frequencywere Atractylodis Macrocephalae Rhizoma-Poria, Citri Reticulatae Pericarpium-Poria, Atractylodis Macrocephalae Rhizoma-Codonopsis Radix, and Poria-Codonopsis Radix. The medicine association rules of confidence coefficient 1 were Sparganii Rhizoma→Curcumae Rhizoma, and Moutan Cortex, Persicae Semen→Paeoniae Radix Rubra. The new prescriptions composited by “Curcumae Rhizoma, Sparganii Rhizoma, Manis Squama, Prunella Spica, Dipsacus Asperoides”, or “Paridis Rhizoma, Adenophorae Radix, Gleditsiae Spina, Sargassum, Laminariae Thallus”. Conclusions Chinese medicinal herbs used in the prescriptions of national TCM masters for the treatment of phymatosis were often with the actions of invigorating the spleen and benefiting qi, clearing away heat and toxic material, and promoting blood circulation to remove blood stasis, which were complied with the medication rule of treating both the incidental and fundamental aspects in TCM.

Objective To investigate the correlation of Bax and apoptosis in enterocytes of neonatal rats with necrotizing enterocolitis (NEC).Methods Forty-eight neonatal rats (1 day) were randomly divided into control group (n =24) and NEC model group (n =24) by use of odd and even.The rats in control group were maternal breast-fed.The rats in NEC model group were separated from their mothers.To be given formula feeding,cold exposure after hypoxic-reoxygenation treatment.The intestinal tissue located at the boundary of ileum and caecum of two groups were gained on the 24 h,48 h and 72 h with which that all rats were sacrificed by cutting neck.Section of intestinal tissue were stained with immunohistochemistry to detect the expression of Bax and were stained with TdT mediated dUTP nick end labeling(TUNEL) to evaluate the apoptosis in each group.Results The integrate optical density (IOD) value of expression of Bax in the NEC model group began to increase on the 24 h [(1 005.06-± 11.96) IOD] and reached the summit on the 72 h [(3 340.66 ±68.72)] compared with the control group[(666.55 ± 15.77)IOD].A few of TUNEL positive cells began to increase with time dependence.A lot of TUNEL positive cells could be found in NEC model group on the 24 h [(15.04 ± 0.24) ％],and the apoptotic index reached the peak on the 72 h [(35.65 ±0.61) ％] compared with the control group[(4.73 ±0.04) ％,P ＜0.01]-There was a significantly positive correlation between the cell apoptosis and the ratio change of Bax in NEC model group (r =0.94,P ＜ 0.01).Conclusion There is a significantly positive correlation between the cell apoptosis and the ratio change of Bax in enterocytes of neonatal rats with NEC.The cell apoptosis in enterocytes of neonatal rats with NEC maybe be induced by Bax.