Objective:To carry out opening experiments on occupational health and occupational medicine for students majoring in preventive medicine, reform the experimental teaching mode, and explore the teaching methods to improve students' professional quality and scientific research ability.Methods:Opening experiments were carried out in the experimental course of occupational health and occupational medicine for students of preventive medicine major. A total of 147 students majoring in preventive medicine of Batch 2016 were classified as the control group, and the routine confirmatory experiment was carried out in the group; 176 students majoring in preventive medicine of Batch 2017 were classified as the experimental group, and this group carried out opening experiment. The evaluation was made from three aspects: comprehensive evaluation results, teacher self-evaluation and student satisfaction survey. SPSS 22.0 software was used for analysis and comparison by independent-samples t-test and Chi-square test. Results:The theoretical scores of the experimental group and the control group students were (84.37±10.45) vs. (81.44±9.22) ( t=2.68, P=0.008), and the experimental skills scores were (93.66±3.89) vs. (88.41±5.67) ( t=9.51, P<0.001). Questionnaire investigation showed that the students in the opening experimental group were more satisfied with the courses arrangement ( χ2=8.31, P=0.004), group cooperation ( χ2=21.10, P<0.001), assessment form ( χ2 =7.92, P=0.005), improvement of the writing ability of scientific research papers ( χ2 =17.56, P<0.001), improvement of practical skills ( χ2=11.70, P=0.001), logical thinking, language organization and expression ability ( χ2=10.33, P=0.001). They considered the opening experiment was helpful to cultivate innovative thinking and ability, but it had limited effect on the cultivation of employment advantages. And the students considered the opening experiments of setting up professional courses was sufficient and necessary. Conclusion:Carrying out opening experiments for students majoring in preventive medicine is helpful to improve students' professional quality and cultivate their practical ability and scientific research ability.

Objective To investigate the effects of long noncoding RNA H19 on lipid accumulation of macrophages under high fat stress and its mechanism. Methods Human THP-1 cells-derived macrophages were incubated with ox-LDL, and the effects of H19 siRNA intervention on lipid accumulation was observed. The THP-1 cells were divided into control group (conventional culture), ox-LDL group, siRNA negative control (NC siRNA) combined with ox-LDL treatment group, and H19 siRNA combined with ox-LDL treatment group. Oil red O staining was used to determine the lipid accumulation in cells, and cholesterol concentration was analyzed by enzymatic method; ATP assay kit for detecting celluar ATP content; colorimetry was used to detect the levels of oxidative stress indicators and ELISA was used to detect the levels of monocyte chemoattractant protein-1 (MCP-1) in the cell supernatant. Western blot analysis was used to detect the protein expression of ATP binding cassette transporter A1 (ABCA1), peroxisome proliferator-activated receptor α (PPARα), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and nuclear factor κB p-p65 (NF-κB p-p65). Results Knockdown H19 significantly inhibited intracellular lipid accumulation, decreased total cholesterol (TC) and cholesterol ester (CE) content, and decreased CE/TC ratio. Knockdown H19 significantly alleviated cell damage including an increase in ATP content, a decrease in oxidative stress levels and a decrease in MCP-1 levels, which caused by high-fat stress. H19 siRNA upregulated expression of ABCA1, PPARα and PGC-1α in THP-1 derived macrophages, downregulated NF-κB signal pathway. Conclusion Knockdown H19 upregulates PGC-1α expression in THP-1 cells and downregulates NF-κB pathway, which promotes cholesterol reverse transport, reduces inflammatory reaction and inhibits lipid accumulation.
Humans ; Adenosine Triphosphate ; Cholesterol ; NF-kappa B ; PPAR alpha ; RNA, Long Noncoding/genetics* ; RNA, Small Interfering/genetics* ; THP-1 Cells ; Macrophages/metabolism* ; Lipid Metabolism

Objective:To investigate the comprehensive ability and influencing factors of clinical medicine graduates from a medical college in Xi'an, and provide a scientific basis for improving the training model and comprehensive ability of clinical medicine students.Methods:Based on the Chinese Undergraduate Medical Education Standard-Clinical Medicine Specialty (2016 Edition), we conducted a self-designed questionnaire, the Clinical Medicine Graduate Comprehensive Ability Evaluation Questionnaire, containing 62 items in 4 dimensions, selected the clinical medicine graduates as the research objects by random sampling method, used SPSS 22.0 to make data analysis, and performed multiple linear regression to analyze its influencing factors.Results:Clinical medicine graduates had the highest score in the field of clinical competence (3.05±0.84), followed by the field of professionalism (2.48±0.81), and the lowest score was in the field of science and academics (1.89±0.68). The top three scores of each factor were clinical practice ability (3.39±0.76), theoretical knowledge mastery (3.55±0.48) and medical knowledge mastery (2.98±0.81). The three factors with the lowest scores were literature search ability (1.31±0.64), global health issues (1.49±0.82) and self-improvement willingness and ability (1.81±0.73). Using the multiple stepwise regression method to analyze the influencing factors of comprehensive ability, the optimal equation was obtained: Y=8.412+0.063 X6+0.190 X8+0.266 X10+0.031 X11+0.187 X12 ( X6, working level; X8, academic performance ranking; X10, practical teaching satisfaction; X11, mode of teaching satisfaction; X12, Re-education satisfaction after graduation). Among them, the higher the practical teaching satisfaction, the satisfaction of re-education and the satisfaction of teaching mode after graduation, the higher the student's performance ranking, and the higher the comprehensive ability score of clinical graduates. Graduates whose employment level was in a general hospitals had higher comprehensive ability scores than those of grassroots hospitals such as community/township hospitals. Conclusions:In the process of training clinical medicine students, we should improve the quality of practical teaching and the teaching model, increase the training of science and academic fields, increase the investment in re-education of primary medical institutions, and raise the satisfaction of graduates in education, so as to improve the clinical medicine profession comprehensive ability of graduates.

Objective:To introduce the clinical dosimetry commissioning methods and results of the 1.5 T MR-linac.Methods:In May, 2019, an Elekta Unity 1.5 T MR-linac was installed in Cancer Hospital, Chinese Academy of Medical Sciences and dosimetry commissioning was performed with magnetic field compatible measuring instruments. Commissioning items include absolute dose calibration, data acquisition and planning system model verification.Results:Absolute dose calibration in magnetic field should be corrected by magnetic field correction factor. The standard output dose of Unity was 87 cGy. Gamma analysis (3%/2 mm) was performed on the beam collection data and the planning system calculation data. The average pass rate of dose verification of standard field test cases was 96.41%, and the TG119 test case was 98.24%. The IROC end to end test case was 97.5%(7%/4 mm).Conclusions:The planning system model and the beam collection data have good consistency. The dose verification results of the standard field and TG119 test cases meet the general tolerance limit requirements of the AAPM TG218 report, and the verification results of the IROC end-to-end test cases meet the IROC center standards.

Objective:To evaluate the effect of fast cone beam CT (CBCT) scan mode on image quality and registration results, and to establish the scanning pre-settings for fast CBCT.Methods:Three scanning modes were utilized to the CBCT phantom, and the registration accuracy and image quality were quantitatively evaluated. The correlation and consistency of measurement results under different scanning modes were further verified by 278 sets of CBCT data from 33 clinical tumor patients.Results:The maximum deviation between the measurement results of three scanning models and the actual value was 0.70 mm (0.51 mm on average). The measurement results of the same location were consistent among three scanning modes (0.00 mm). For the uniformity, the results of the normal mode were the best (3.62% on average), followed by the fast 1 mode (3.90% on average) and the fast 2 mode (4.84% on average). For the noise, the results of the normal mode were the best (15.69 on average), followed by the fast 2 mode (17.23 on average) and the fast 1 mode (21.74 on average). Regarding the high contrast resolution, the measurement results of three scanning modes were consistent (at least 3 pairs could be distinguished). For the low contrast resolution, the results of the fast 1 mode were the best (1.69 on average), followed by the normal mode (2.10 on average), and the fast 2 mode (2.31 on average). For the geometric accuracy, the measurement results of the three scanning modes were basically consistent with a mean deviation of 0.05 mm. The correlation of the measurement results between normal mode and fast 1 mode was the highest in clinical cases ( R2>0.90, P<0.01) with a high degree of consistency (95% consistency limit of the above two scanning modes< 1 mm threshold). Conclusion:Compared with the normal mode, the fast 1 mode can yield equivalent image quality, consistent registration results, faster scanning speed and lower scanning dose. Therefore, the fast 1 mode is recommended as the scan mode in clinical practice.

Objective:The Lorentz force produced by magnetic field deflects the paths of secondary electrons. The X-ray beam dosimetry characteristics of the magnetic resonance accelerator (MR-Linac) are different from conventional accelerators. The purpose of this study was to measure and analyze the X-ray beam dosimetry characteristics of 1.5T MR-Linac.Methods:In May 2019, our hospital installed a Unity 1.5T MR-Linac and measured it with magnetic field compatible tools. The measurement indexes include: surface dose, maximum dose point depth, beam quality, off-axis dose profile center, beam symmetry, penumbra width, output changes of different gantry angles.Results:The average surface dose was 40.48%, and the average maximum dose depth was 1.25 cm. The center of the 10 cm×10 cm beam field was offset by 1.47 mm to the x2 side and 0.3 mm to the y2 side. The x-axis symmetry was 101.33%, and the penumbra width on both sides was 6.86 mm and 7.14 mm, respectively. The y-axis symmetry was 100.85%, and the penumbra width on both sides was 5.92 mm and 5.95 mm, respectively. The maximum deviation of output dose with different gantry angles reached 1.50%. Conclusions:The surface dose of MR-Linac tend to be consistent, and the depth of the maximum dose point became shallower. The off-axis in the x-axis direction was shifted to the x2 side, which resulting in worse symmetry and penumbra asymmetry. The output dose at different angles has obvious variation and needs correction.

Objective The IAEA report No.483 describes the latest method of small field dosimetry.The field output factor measurement and correction methods are used to improve the accuracy and consistency of the measurement results for different type detectors.Methods The field output factors from 0.6 cm×0.6 cm to 10 cm× 10 cm were measured using IBA's CC13 ionization chamber,CC01 ionization chamber,PFD semiconductor detector,EFD semiconductor detector and Razor semiconductor detector,respectively.The field output correction factors were used to correct the measurement result.Results Compared with the corrected data,the results of ionization chamber are mainly affected by the volume averaging and the fluence perturbation effect,lead to the measurement result which is 4.70％ lower at 0.6 cm × 0.6 cm;The results of Shielded semiconductors are mainly affected by fluence perturbation effect,lead to the measurement result which is 4.80％ higher at 0.6 cm × 0.6 cm.The results of unshielded semiconductors are mainly affected by energy response and fluence perturbation effect,resulting in lower measurement results at the field size＞0.8 cm×0.8 cm,2.10％ lower at field size of 1.5 cm× 1.5 cm,higher measurement results at field size＜0.8 cm×0.8 cm and 1.1％ higher at field size of 0.6 cm×0.6 cm.Before the correction,the measurement results from different types of detectors are quite different,average standard deviation is 0.016 6.After the correction,the difference among the detectors is significantly reduced,average standard deviation is 0.006 6.Conclusions For detectors such as ionization chambers and semiconductors,the field output correction factors can be used to correct the output factors of the small field to improve the accuracy and consistency of the measurement results.

OBJECTIVE: To determine the effects of hawthorn extract on serum lipid levels, pathological changes in aortic atherosclerosis plaque, inflammatory factors, and apoptosis-related protein and mRNA expression in apolipoprotein E gene knockout (ApoE) mice. METHODS: Thirty-six ApoE mice were fed with a high-fat diet starting at the age of 8 weeks. Mice were randomly divided into 3 groups by a random number table including model group, hawthorn extract group, and simvastatin group, 12 mice in each group. Twelve 8-week-old C57BL/6 mice were fed a basic diet and served as control. The mice in the control and model groups were administered 0.2 mL saline daily, the mice in the hawthorn extract and simvastatin groups were administered with 50 mg/kg hawthorn extract or 5 mg/kg simvastatin daily for 16 weeks. After 16 weeks, plasma lipids including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were determined by an enzymatic assay. Aortic atherosclerotic lesions were observed by light microscopy, scanning and transmission electron microscopy, respectively. Plasma levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-1β (IL-1β), adiponectin (APN), and hypersensitive C-reactive protein (hs-CRP) were measured by enzyme-linked immunosorbent assay (ELISA). Protein and mRNA expressions of Bax and Bcl-2 in the aorta were assessed by Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. RESULTS: Compared to the control group, the plasma levels of TC, TG and LDL-C were significantly increased and HDL-C were significantly decreased in the model group (P<0.01). Compared to the model group, treatment with hawthorn extract significantly decreased the plasma levels of TC, TG, and LDL-C and increased the plasma level of HDL-C in ApoE mice (P<0.01). The levels of MCP-1, IL-1ß, and hs-CRP in the model group were significantly increased and APN was significantly decreased compared with the control group (P<0.01). Compared to the model group, treatment with hawthorn extract decreased the levels of MCP-1, IL-1ß, and hs-CRP and increased the APN level (P<0.01). Compared to the control group, the protein and mRNA expression of Bax in the model group were significantly increased and the expression of Bcl-2 was significantly decreased (P<0.01). Hawthorn extract also reduced the protein and mRNA expression of Bax and increased the Bcl-2 expression in the aorta (P<0.01). CONCLUSION Hawthorn extract has anti-atherosclerosis and stabilizing unstable plaque effects. The mechanism may be related to the inflflammation and apoptosis signaling pathways.
Animals ; Aorta ; pathology ; ultrastructure ; Apoptosis ; drug effects ; Atherosclerosis ; blood ; complications ; drug therapy ; Crataegus ; chemistry ; Inflammation ; blood ; complications ; drug therapy ; Inflammation Mediators ; metabolism ; Lipids ; blood ; Male ; Mice, Inbred C57BL ; Plant Extracts ; pharmacology ; therapeutic use ; RNA, Messenger ; genetics ; metabolism ; bcl-2-Associated X Protein ; metabolism

Objective improve the accuracy of the measurement results by using the field output factor measurement method based on daisy-chaining.Methods The Varian Edge Accelerator 6 MV X-ray data were measured using the IBA CC13 ionization chamber, IBA CC01 ionization chamber, IBA Razor semiconductor detector , IBA EFD semiconductor detector and Gafchromic EBT 3 film , respectively. Results Compared with the daisy-chaining measurement method,the results obtained by the conventional measurement method using CC13 were smaller. The deviation value was 16. 71% in the 1 cm × 1 cm field. The measurement results in a larger field via CC01 were bigger with a deviation of 8. 39% in the 40 cm × 40 cm filed. The measurement results via Razor in a larger field were larger with a deviation of 9. 40% in the 40 cm × 40 cm field. The measurement results were similar between EFD and Razor with a deviation of 9. 14% in the 40 cm × 40 cm field. The results of the film measurement were equivalent to those obtained from the daisy-chaining method in a field of＞ 1 cm × 1 cm with a deviation within 1. 60%,whereas the deviation was increased to 3. 13% in the 1 cm× 1 cm field. The results were consistent with daisy-chaining measurement if the 3 cm × 3 cm or 4 cm × 4 cm fields were selected as the intermediate fields with the maximum deviation of 0. 29%. Conclusions For the detectors with changing response along with the field size,daisy-chaining measurement method can be utilized to extend the measurement range and improve the accuracy of the measurement results.

Objective To explore the mechanical properties of erythrocytes in the patients with hypertension.Methods Venous blood of 32 patients with hypertension were collected and divided into three groups of H1,H2,and H3 (degree Ⅰ,Ⅱ,Ⅲ),with 8 cases of healthy adults into a control group.Erythrocytes were isolated,the diameter,height and elastic modulus were detected by the atomic force microscope (AFM).Statistical analysis was carried out.Results The RDW-CV of H2,H3 were much larger than the control group (P＜0.05,P＜0.01);The height of erythrocyte in H2,H3 groups were lower than that of the control group (P＜0.05).The elastic modulus of H 1,H2 groups were larger compared with normal erythrocytes (P＜0.05).Furthermore,erythrocytes elastic modulus correlated with RDW-CV (R2=0.629).Conclusion Hypertension could affect the elasticity modulus of erythrocytes.AFM could be an effective tool in measuring the mechanical characteristics of erythrocytes at single cell level.This study investigates the relationship between hypertension and the structure and function of erythrocytes from a biomechanical aspect.