Objective The distribution of the photon energy spectrum in isocenter plane of the medical linear accelerator and the influence of secondary collimator on the photon energy spectrum are studied.Methods Use the BEAMnrc program to simulate the transmission of the 6 MeV electrons and photons in 5 cm×5 cm,10 cm×10 cm,15 cm×15 cm and 20 cm×20 cm fields in treatment head of the medical linear accelerator,where a phase space file was set up at the isocenter plane to record the particle information passing through this plane.The BEAMdp program is used to analyze the phase space file,in order to obtain the distribution of the photon energy spectrum in isocenter plane and the influence of secondary collimator on the photon energy spectrum.Results By analyzing the photon energy spectrum of a medical linear accelerator with a nominal energy of 6 MV,it is found that the secondary collimator has little effect on the photon energy spectrum;different fields have different photon energy spectrum distributions;the photon energy spectrum in different central regions of the same field have the same normalized distribution.Conclusion In the dose calculation of radiation therapy,the influence of photon energy spectrum should be carefully considered.

Objective:To investigate the characteristics of gut microbiota in patients with type 2 diabetes (T2DM) complicated by nonalcoholic fatty liver disease (NAFLD).Methods:A total of 74 patients first diagnosed with T2DM at the Endocrinology Department of Peking Union Medical College Hospital from April 2021 to October 2023 were included. Among them, 28 patients had concurrent NAFLD while 46 patients did not. Additionally, 51 healthy controls were matched (HC group). Clinical laboratory parameters were collected, and 16S rRNA sequencing with fecal samples was conducted to compare the differences in gut microbiota across the groups.Results:Compared to the group with T2DM, patients with concurrent T2DM and NAFLD were younger, had higher level of insulin resistance as assessed by the homeostatic model assessment of insulin resistance, higher body mass index (BMI), and higher triglyceride levels. There was no difference in α-diversity across the three groups ( P>0.05), while there was a significant difference in β-diversity ( P=0.03). The Eubacterium coprostanoligenes, Fusicatenibacter, Parasutterella and Tyzzerella 3 were enriched in the group with concurrent T2DM and NAFLD as shown by the relative abundance, while the relative abundance of Flavonifractor was decreased in this group. Tyzzerella 3 abundance was positively correlated with triglyceride and albumin levels and negatively correlated with high-density lipoprotein cholesterol (HDL-C) levels. Conclusion:Patients with T2DM complicated by NAFLD exhibit dysbiosis in gut microbiota composition and specific genera abundance, with Flavonifractor identified as a potential protective factor for T2DM complicated by NAFLD.

Objective:To investigate the predictive performance of triglyceride and triglyceride glucose (TyG) index in the first trimester for the onset of gestational diabetes mellitus (GDM).Methods:Pregnant women who visited Beijing Chaoyang Maternal and Child Health Care Hospital and Beijing Haidian Maternal and Child Health Care Hospital from 2019 to 2022 were prospectively included. Concurrently, 78 healthy non-pregnant women who visited the Department of Endocrinology of Peking Union Medical College Hospital were included. The clinical characteristics and laboratory biomarkers including fasting blood glucose and blood lipid profiles were collected at the first visit in early pregnancy. Oral glucose tolerance test (OGTT) was performed at 24-28 weeks of gestation for GDM screening. Multivariate Logistic regression analysis was used to determine the association between biomarkers in early pregnancy and the risk of GDM. The receiver operating characteristic curve was used to evaluate the predictive performance and to identify the optimal cut-off value of triglyceride and TyG index in the first trimester for the risk of GDM.Results:A total of 1 677 pregnant women were included in this study, and the prevalence of GDM in our cohort was 19.6%. Compared with women who did not develop GDM, women with GDM showed an older maternal age, higher pre-pregnancy body mass index, and increased levels of laboratory biomarkers including fasting blood glucose, fasting insulin, total cholesterol, triglyceride, low-density lipoprotein cholesterol, TyG index, and Homeostasis Model Assessment of Insulin Resistance ( P<0.001). Logistic regression analysis showed that both triglyceride and TyG index in the first trimester were independent risk factors for GDM. The optimal cut-off values of triglyceride and TyG index for predicting the risk of GDM were 0.93 mmol/L and 8.10, respectively. The predictive performance can be further improved if maternal age and pre-pregnancy BMI are included. Conclusion:Triglyceride and TyG index in early pregnancy are closely associated with the risk of GDM, and can be used as early predictors of GDM.

Objective:The decline in nutritional status in patients with severe pneumonia may contribute to an increase in in-hospital mortality. Enteral nutrition support can improve the nutritional status of patients, and is relatively easy to manage, with low cost and fewer serious complications. On the other hand, adverse reactions such as gastric retention and gastric microbiota translocation may increase the incidence of nosocomial pneumonia and increase the uncertainty of patient prognosis. There is no predictive model for in-hospital death in severe pneumonia patients receiving enteral nutrition support. The objective of this study was to investigate the risk factors of in-hospital death in patients with severe pneumonia receiving enteral nutrition support and to establish a prognostic model for such patients.Methods:This was a single-center retrospective study. Patients with severe pneumonia who were hospitalized in Peking Union Medical College Hospital and received enteral nutrition support were included from January 1, 2015 to December 31, 2020. The primary endpoints were in-hospital mortality rate and unordered discharge rate. The independent risk factors were determined using univariate and multifactorial logistic regression analysis, the nomogram scoring model was constructed, and the decision curve analysis (DCA) was performed.Results:A total of 632 severe pneumonia patients who received enteral nutrition support were included. Patients were divided into death and survival groups according to the presence or absence of in-hospital death, and 24 parameters were found with significant differences between groups. Nine parameters were independent predictors of mortality, namely the duration of ventilator use, the presence of malignant hyperplasia diseases, the maximal levels of platelet and prothrombin during hospitalization, and the nadir levels of alanine aminotransferase, serum albumin, sodium, potassium, and blood glucose. Based on these variables, a risk prediction scoring model was established (ROC = 0.782; 95% CI: 0.744 to 0.819, concordance index: 0.772). Calibration curves, DCA, and clinical impact curve were plotted to evaluate the goodness of function, accuracy, and applicability of the predictive nomogram, using the training and test sets. Conclusion:This study summarized the clinical characteristics of patients with severe pneumonia receiving enteral nutrition support and developed a scoring model to identify risk factors and establish prognostic models.

Objective:To explore the application effect of parent-child emotional regulation and resilience group training in adolescent depression patients.Methods:From August 2020 to September 2021, a total of 118 adolescent depression patients were enrolled and randomly divided into the intervention group(66 cases) and the control group(66 cases) by a random number table method.The intervention group received medication therapy and parent-child group emotional regulation and psychological resilience training, while the control group received medication therapy and commonly used individual, family or group therapy in clinical practice.The Hamilton Depression rating scale(HAMD-24 version), Herth hope scale(HHS), Connor-Davidson resilience scale(CD-RISC), and family adaptability and cohesion evaluation scale, second edition Chinese version(FACES-Ⅱ-CV) were adopted to investigate participants at baseline, 12-week, 24-week, and 36-week after intervention.SPSS 26.0 statistical software was used to perform repeated measurement analysis of variance on the data.Results:(1)The interaction effect between two groups of HAMD scores( F=54.0, P<0.001), group main effect( F=401.4, P<0.001), and time main effect( F=116.6, P<0.001) were all significant.Further simple effect analysis showed that there were statistically significant differences in HAMD scores at various time points after intervention between the intervention group(26.2±6.5, 19.3±5.9, 11.3±5.6) and the control group(33.1±9.1, 30.3±7.9, 25.0±8.4)(all P<0.05). Intragroup comparison showed the HAMD scores of the intervention group and control group at each time point after intervention were lower than those before intervention (all P<0.05). (2)The interaction effect of CD-RISC scores between two groups of patients( F=72.1, P<0.001), group main effect( F=48.9, P<0.001), and time main effect( F=174.9, P<0.001) were significant.Further simple effect analysis showed that the CD-RISC score of the intervention group at each time point after intervention were higher than those of the control group(all P<0.05). Intragroup comparison showed the scores of CD-RISC at each time point after intervention in the intervention group and the control group were higher than those before intervention(all P<0.05). (3)The interaction effect of HHS scores( F=121.6, P<0.001), group main effect( F=57.4, P<0.001), and time main effect( F=208.1, P<0.001) of the two groups of patients were significant.Further simple effect analysis showed that the HHS scores of the intervention group were higher than those of the control group at all time points after intervention(all P<0.05). Intragroup comparison showed the HHS scores of the intervention group and the control group at each time point after intervention were higher than those before intervention(all P<0.05). (4)The interaction effect of FACES-Ⅱ-CV scores( F=45.0, P<0.001), group main effect( F=20.3, P<0.001), and time main effect( F=154.5, P<0.001) of the two groups of patients were significant.Further simple effect analysis showed that the FACES-Ⅱ-CV scores of the intervention group were higher than those of the control group at all time points after intervention(all P<0.05). Intragroup comparison showed the FACES-Ⅱ-CV scores of the intervention group and the control group at each time point after intervention were higher than those before intervention(all P<0.05). (5)The total effective rate of the intervention group was higher than that of the control group(95.1%, 87.7%)( P<0.001). Conclusion:In adolescents with depression, parent-child group emotional regulation and resilience training can effectively reduce depression emotion, increase the level of hope and resilience of patients and enhance family intimacy and adaptability.

Objective:To explore the intention of exclusive breastfeeding and its influencing factors within six months after delivery of pregnant women in the third trimester of pregnancy in Xi'an.Methods:From January to February 2019, convenience sampling was used to select 2 671 pregnant women in the third trimester of pregnancy who underwent regular obstetric examinations in Obstetrics Clinic of five hospitals in Xi'an for a cross-sectional survey. Pregnant women were surveyed by means of a field survey using a self-designed Exclusive Breastfeeding Intention of Pregnant Women in the Third Trimester Questionnaire. Multivariate Logistic regression was used to analyze the influencing factors of the intention of exclusive breastfeeding among pregnant women in the third trimester. A total of 2 671 questionnaires were distributed, 2 479 valid questionnaires were recovered, and the valid recovery rate was 92.8% (2 479/2 671) .Results:A total of 60.8% (1 507/2 479) of pregnant women planned to exclusively breastfeed within 6 months of delivery. Pregnant women in the third trimester of pregnancy whose husbands ( OR=2.950, 95% CI: 2.097-4.066) and family members ( OR=2.171, 95% CI: 1.571-3.000) supported exclusive breastfeeding had high intention to exclusively breastfeed, and those who participated in breastfeeding courses had a high intention to exclusively breastfeed ( OR=1.436, 95% CI: 1.199-1.719) . Conclusions:More than half of third-trimester women plan to exclusively breastfeed within six months postpartum. Husband and family support and enrolment in breastfeeding classes increase the intention of pregnant women to exclusively breastfeed. Prenatal breastfeeding courses should be carried out to raise the awareness of pregnant women and family members about exclusive breastfeeding, and focus on the support of husbands and family members for exclusive breastfeeding, so as to increase the exclusive breastfeeding rate within six months after delivery.

Objective:To explore effects of mindfulness training on the psychological resilience, subjective well-being and blood glucose metabolism indexes of middle-aged and young diabetic patients.Methods:From April to September 2019, convenience sampling was used to select 100 inpatient diabetic patients admitted to the Endocrinology Department of a provincial hospital in Hebei Province. The patients were divided into the control group and the observation group with the random number table method, each with 50 cases. The control group was given routine nursing, and the observation group was given mindfulness training on the basis of routine nursing. The psychological resilience, subjective well-being and blood glucose metabolism indexes of the two groups of patients were evaluated before the intervention and 6 months after the intervention.Results:Before the intervention, there was no statistically significant difference in the psychological resilience, subjective well-being scores, and blood glucose metabolism indexes of patients between two groups ( P>0.05) . After the intervention, the scores of psychological resilience and subjective well-being of observation group were (63.04±3.19) and (71.67±5.40) respectively, higher than those [ (50.68±3.50) and (53.83±6.06) ] of the control group, and the fasting blood glucose, 2 hours postprandial blood glucose, and glycosylated hemoglobin of the observation group were lower than those of the control group, and the differences were statistically significant ( P<0.05) . Conclusions:Mindfulness training can improve the psychological resilience, subjective well-being, and blood glucose control of young and middle-aged diabetic patients.

Objective:To analyze the performance of clinical theoretical examination of the five year clinical medical students in a medical school, and to explore the existing problems and direction involving in the medical education.Methods:The difficulty coefficient and degree of discrimination were used to analyze the quality of this test, and F test and LSD- t test were conducted with SPSS 24.0 to analyze the mastery rate of various modules and secondary disciplines including basic medicine, medical humanities, clinical medicine and preventive medicine. Results:The overall difficulty coefficient of the test was 0.74, and the degree of discrimination was 0.37. The coefficient of difficulty of each module is more than 0.70, and the degree of discrimination is about 0.40. The mastery rates of each module were all greater than 70%, with clinical medicine being the highest and medical humanities and basic medicine being the lowest, and the mastery rate of each secondary discipline was more than 60%, with a significant difference.Conclusion:This exam is sample, the degree of discrimination is good, and the overall knowledge is well mastered. However, it is still necessary to innovate education reform and improve the teaching quality based on weak points.

With the market-oriented application of new technologies and the development of various subjects in hospitals, more and more point-of-care test(POCT) devices appear in medical institutions, as an important method for rapid clinical acquisition of test results. As introduced by the authors, the hospital since 2017, established based on the hospital′s total quality management system, the POCT management committee, and built the hospital′s POCT quality management system. Thanks to its efforts, the hospital has fully standardized the POCT management from equipment procurement, test, maintenance, personnel training and examination, thus further ensuring medical quality.

Objective To evaluate the effects of mindfulness training on diabetes-related distress and quality of life in patients with type 2 diabetes mellitus, so as to provide evidence for nursing interventions. Methods A total of 90 inpatients with type 2 diabetes mellitus were randomly assigned to a control group and an observation group of 45 cases. The control group received routine health education, while the observation group received mindfulness training by the mindfulness training team composed of seven members including psychological counselors and nurse educators. Both groups were followed up for 6 months, and the scores of diabetes-related distress and quality of life were measured before and 6 months after the intervention. t-test was adopted to compare the difference between the two groups. Results After the intervention, the total score and scores of each dimension of diabetes-related distress in the observation group were (1.81±0.40), (1.99±0.45), (1.45±0.20), (2.01±0.27), and (1.51±0.21) respectively. Correspondingly, the scores of the control group were (2.07±0.24), (2.21±0.40), (1.61±0.19), (2.57±0.25) and (2.20±0.23), which were all higher than the observation group, with statistical differences (t=3.54, 2.32, 3.69, 9.68, 14.11;P<0.05). The scores of quality of life in disease dimension, physiological dimension, psychological dimension, social dimension and satisfaction dimension were (28.41±5.40), (21.05±4.16), (21.08±5.16), (19.04±3.30) and (22.84±3.79) in the observation group, which were all lower than those in the control group respectively [(36.08±5.20), (23.80±5.00), (24.11±5.22), (21.34±3.47), (24.64±3.50)], the differences were statistically significant (t=6.51, 2.69, 2.63, 3.06, 2.22;P< 0.05). Conclusions Mindfulness training can reduce the degree of diabetes-related distress and improve the quality of life in patients with type 2 diabetes mellitus.