Objective: To investigate the effect of sirtuin 2(SIRT2) on the proliferation and migration of cardiac fibroblasts(CFs)in C57BL/6 mice under angiotensin II(Ang Ⅱ) stimulation. Methods : The hearts were taken from 1 to 2 days C57BL/6 milk mice. After cutting and digesting, CFs were extracted by different adhesion centrifugation. After CFs attachment, the cells were cultured under control medium and Ang Ⅱ(100 nmol/L) medium and treated using OE-SIRT2 plasmid to overexpression the SIRT2 gene. RT-qPCR was used to detect mRNA expression of SIRT2 proliferating cell nuclear antigen(PCNA), periostin(POSTN)and type Ⅰ collagen procollagen A1(Col1A1), Western blot assay was used to measure the protein expression levels of SIRT2, PCNA, POSTN and Col1A1, CCK-8 assay and EdU assay were used to evaluate CFs proliferation rate, Transwell experiment was used to assess CFs migration activity. Results: Compared with control group, Ang Ⅱ stimulation led to down-regulation of SIRT2 expression in CFs, increased collagen expression, and promoted CFs proliferation and migration. The expression of SIRT2 was up regulated in CFs treated with OE-SIRT2 plasmid under Ang Ⅱ stimulation, Col1A1, POSTN and PCNA expression was down regulated, and CFs proliferation and migration ability decreased. Conclusion Overexpression of SIRT2 can inhibit the proliferation and migration of CFs under Ang Ⅱ stimulation, indicating that SIRT2 may be a key regulatory point in the onset and progression of cardiac fibrosis.

Objective:To explore the influence of different scanning positions based on chest phantom of computed tomography(CT)scan on chest on image quality and radiation dose.Methods:A thermoluminescent dosimeter(TLD)was placed at the breast area of simulating anthropoid chest phantom.GE Revolution evo CT was used to conduct scan on the conventional supine position(supine group)and prone position(prone group)for chest phantom.Different noise indexes(NI=10-23)were adjusted to control ration doses,and other parameters were fixed,and each group collected 12 sequence images.The average value(AV),standard deviation(SD)of the CT scan at region of interest(ROI)under different scanning positions were recorded to calculate the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of the image.The radiation dose at the breast area was measured by TLD,and the volume CT dose index(CTDIvol)and dose-length product(DLP)were recorded.Results:Under different scanning positions,the radiation dose of breast organs in the prone group was lower than that in the supine group,there was a statistically significant difference between the two groups(t=6.57,P<0.05),while there were not statistically significant differences in CTDIvol and DLP between the two groups(P>0.05).There were not statistically significant differences in the CT values,SD,SNR,CNR of lung tissue,and the CT values of breast tissue between the two groups of images(P>0.05).The SD,SNR and CNR of breast tissue in the prone group were lower than those in the supine group,and the differences were statistically significant(t=-13.33,-10.59,6.70,P<0.05).There were no statistically significant differences in the subjective scores of the clarity of the edge of the tissue within lung,the layers of soft tissue of the breast,noise,and artifacts in the bone tissue between the two groups of images(P>0.05).Conclusion:When low-dose CT physical examination on chest is conducted in clinical practice,the scanning of prone position during undergoing CT scan on chest can obtain image quality that can meet the requirements in diagnosing lung,and reduce the radiation dose on the breast,and conform to the technical principle of optimal radiation protection.

Objective To investigate the knee disorders and risk factors in electromechanical soldiers of a warship,so as to provide a basis for prevention and treatment measures.Methods The knee disorders and treatment data of 200 electromechanical soldiers(study group)and 200 soldiers from other departments(control group)were colected by questionnaire survey and medical records.Results The incidence of knee diseases was 37.5%(75 cases)in the study group,which was significantly higher than that in the control group(16.0%,32 cases,P＜0.05).Traumatic and degenerative diseases were the main types of knee disorders.Age and body mass index were the influencing factors of knee disorders in electromechanical soldiers.Conclusion There is a high incidence of knee disorders in electromechanical soldiers,which is related to a variety of factors.Appropriate prevention and treatment measures are of great significance to reduce the incidence of knee disorders,promote rapid recovery,and reduce non-combat casualty.

Aim To investigate the effect of N6-methy-ladenosine(m6A)demethylase ALKBH5 on the prolif-eration and migration of cardiac fibroblasts(CFs)in-duced by high glucose.Methods Primary CFs were isolated from neonatal mouse hearts and identified u-sing optical and confocal microscopy.Cell activation was induced using a high-glucose medium(33 mmol·L-1 glucose).An ALKBH5 overexpression model was established by transfecting CFs with an ALKBH5 ex-pression vector in a high-glucose medium.The expres-sion of ALKBH5 in CFs was assessed through immuno-fluorescence staining,Western blot and RT-qPCR.Changes in m6A levels were evaluated using Dot blot a-nalysis.Additionally,Alterations in the expression of proliferating cell nuclear antigen(PCNA)and collagenⅠ,a pivotal fibrosis indicator,were measured using Western blot.The proliferation and migration ability of CFs were assessed through EdU staining and Transwell migration assay,respectively.Results Following treatment with high glucose,the expression of ALKBH5 in CFs notably decreased,while m6A level increased.This was accompanied by a significant increase in the expression of the proliferation marker PCNA and the fi-brosis marker collagen Ⅰ.Additionally,there was a sig-nificant improvement in the ability of proliferation and migration.Overexpression of ALKBH5 resulted in a significant decrease in the expressions of PCNA and collagen Ⅰ,leading to the inhibition of both proliferation and migration in CFs.Conclusion Overexpression of ALKBH5 suppresses the expression of PCNA and colla-gen Ⅰ,consequently reducing the proliferation and mi-gration of CFs,potentially through m6A methylation modification.

Aim To investigate the effect of N6-methy-ladenosine(m6A)demethylase ALKBH5 on the prolif-eration and migration of cardiac fibroblasts(CFs)in-duced by high glucose.Methods Primary CFs were isolated from neonatal mouse hearts and identified u-sing optical and confocal microscopy.Cell activation was induced using a high-glucose medium(33 mmol·L-1 glucose).An ALKBH5 overexpression model was established by transfecting CFs with an ALKBH5 ex-pression vector in a high-glucose medium.The expres-sion of ALKBH5 in CFs was assessed through immuno-fluorescence staining,Western blot and RT-qPCR.Changes in m6A levels were evaluated using Dot blot a-nalysis.Additionally,Alterations in the expression of proliferating cell nuclear antigen(PCNA)and collagenⅠ,a pivotal fibrosis indicator,were measured using Western blot.The proliferation and migration ability of CFs were assessed through EdU staining and Transwell migration assay,respectively.Results Following treatment with high glucose,the expression of ALKBH5 in CFs notably decreased,while m6A level increased.This was accompanied by a significant increase in the expression of the proliferation marker PCNA and the fi-brosis marker collagen Ⅰ.Additionally,there was a sig-nificant improvement in the ability of proliferation and migration.Overexpression of ALKBH5 resulted in a significant decrease in the expressions of PCNA and collagen Ⅰ,leading to the inhibition of both proliferation and migration in CFs.Conclusion Overexpression of ALKBH5 suppresses the expression of PCNA and colla-gen Ⅰ,consequently reducing the proliferation and mi-gration of CFs,potentially through m6A methylation modification.

As the most common phenotype of type 1 neurofibromatosis(NF1),plexiform neurofibromas(pNF)exhibit early asymptomatic presentation but multisite involvement,with a risk of progression.Imaging serves as vital tool for evaluation and management of NF1-associated pNF.The progresses of imaging for evaluating NF1-related pNF were reviewed in this article.

As the most common phenotype of type 1 neurofibromatosis(NF1),plexiform neurofibromas(pNF)exhibit early asymptomatic presentation but multisite involvement,with a risk of progression.Imaging serves as vital tool for evaluation and management of NF1-associated pNF.The progresses of imaging for evaluating NF1-related pNF were reviewed in this article.

Objective:To explore the influence of different scanning positions based on chest phantom of computed tomography(CT)scan on chest on image quality and radiation dose.Methods:A thermoluminescent dosimeter(TLD)was placed at the breast area of simulating anthropoid chest phantom.GE Revolution evo CT was used to conduct scan on the conventional supine position(supine group)and prone position(prone group)for chest phantom.Different noise indexes(NI=10-23)were adjusted to control ration doses,and other parameters were fixed,and each group collected 12 sequence images.The average value(AV),standard deviation(SD)of the CT scan at region of interest(ROI)under different scanning positions were recorded to calculate the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of the image.The radiation dose at the breast area was measured by TLD,and the volume CT dose index(CTDIvol)and dose-length product(DLP)were recorded.Results:Under different scanning positions,the radiation dose of breast organs in the prone group was lower than that in the supine group,there was a statistically significant difference between the two groups(t=6.57,P<0.05),while there were not statistically significant differences in CTDIvol and DLP between the two groups(P>0.05).There were not statistically significant differences in the CT values,SD,SNR,CNR of lung tissue,and the CT values of breast tissue between the two groups of images(P>0.05).The SD,SNR and CNR of breast tissue in the prone group were lower than those in the supine group,and the differences were statistically significant(t=-13.33,-10.59,6.70,P<0.05).There were no statistically significant differences in the subjective scores of the clarity of the edge of the tissue within lung,the layers of soft tissue of the breast,noise,and artifacts in the bone tissue between the two groups of images(P>0.05).Conclusion:When low-dose CT physical examination on chest is conducted in clinical practice,the scanning of prone position during undergoing CT scan on chest can obtain image quality that can meet the requirements in diagnosing lung,and reduce the radiation dose on the breast,and conform to the technical principle of optimal radiation protection.

A dose reconstruction algorithm for electrionic portal imaging device(EPID)based on calibration and calculation is developed.The raw data of EPID in continuous acquisition mode are corrected for dark field and gain,and the gray level features of bright field are used to determine the field boundary.Subsequently,MU calibration,off-axis calibration and field size calibration are performed on the EPID data,and dose reconstruction is carried out based on the calibrated superimposed flux and the Monte Carlo model of the linac head.Nine cases of IMRT plans are selected for verification and measurement using EPID and MapCheck separately,and the passing rates between the two tools are compared under different gamma criteria(3%/3 mm and 2%/2 mm).For a planned case,the average passing rates of multiple cases verified by MapCheck under the two criteria were 99.02%±1.28%and 90.84%±4.49%,and the average passing rates of the EPID reconstruction models were 98.86%±1.19%and 91.39%±4.80%.Compared with MapCheck,the EPID reconstruction algorithm based on calibration and calculation has no significant difference in the passing rate of IMRT plan verification(P＞0.05),which meets the clinical requirements of dose verification.

Objective A quality control(QC)system based on the electronic portal imaging device(EPID)system was used to realize the Multi-Leaf Collimator(MLC)position verification and dose verification functions on Primus and VenusX accelerators.Methods The MLC positions were calculated by the maximum gradient method of gray values to evaluate the deviation.The dose of images acquired by EPID were reconstructed using the algorithm combining dose calibration and dose calculation.The dose data obtained by EPID and two-dimensional matrix(MapCheck/PTW)were compared with the dose calculated by Pinnacle/TiGRT TPS for γ passing rate analysis.Results The position error of VenusX MLC was less than 1 mm.The position error of Primus MLC was significantly reduced after being recalibrated under the instructions of EPID.For the dose reconstructed by EPID,the average γ passing rates of Primus were 98.86%and 91.39%under the criteria of 3%/3 mm,10%threshold and 2%/2 mm,10%threshold,respectively.The average γ passing rates of VenusX were 98.49%and 91.11%,respectively.Conclusion The EPID-based accelerator quality control system can improve the efficiency of accelerator quality control and reduce the workload of physicists.