1.A Geant4-based research on radiation field distribution in a 9 MeV e-FLASH treatment room
Deqi CHENG ; Qin YANG ; Xufan HUANG ; Peng WU ; Haoran XIE ; Jing XIA ; Erfeng WANG ; Guofu YU ; Yu JIANG ; Xianhong LIU
Chinese Journal of Radiological Medicine and Protection 2025;45(11):1152-1156
Objective:To investigate the radiation field distribution characteristics in a 9 MeV electron FLASH (e-FLASH) linear accelerator treatment room.Methods:The Geant4 Monte Carlo program was employed for physical simulating of the radiation field distribution inside and outside the treatment room under a single-beam delivery condition with a total dose of 50 Gy at the reference point and a dose rate of 250 Gy/s. High-sensitivity radiation detectors (AT1123) were used to validate the measurements at key points.Results:The dose rate at the reference point was approximately 9×10 11 μSv/h. Due to the scattering and shielding effects, the deviation of the attenuation rate from the inverse-square law was observed and the isodose lines exhibited spatial drift. Measured dose rates at key points showed good agreement with the simulation result, with a maximum deviation within 30%. Conclusions:The complex radiation field distribution can be effectively simulated using Geant4 in an e-FLASH treatment room. This indicated the Geant4 is not only applicable for the shielding calculations in e-FLASH radiotherapy facilities, but also for the design optimization through, reduction of trial-and-error iterations and engineering costs.
2.A Geant4-based research on radiation field distribution in a 9 MeV e-FLASH treatment room
Deqi CHENG ; Qin YANG ; Xufan HUANG ; Peng WU ; Haoran XIE ; Jing XIA ; Erfeng WANG ; Guofu YU ; Yu JIANG ; Xianhong LIU
Chinese Journal of Radiological Medicine and Protection 2025;45(11):1152-1156
Objective:To investigate the radiation field distribution characteristics in a 9 MeV electron FLASH (e-FLASH) linear accelerator treatment room.Methods:The Geant4 Monte Carlo program was employed for physical simulating of the radiation field distribution inside and outside the treatment room under a single-beam delivery condition with a total dose of 50 Gy at the reference point and a dose rate of 250 Gy/s. High-sensitivity radiation detectors (AT1123) were used to validate the measurements at key points.Results:The dose rate at the reference point was approximately 9×10 11 μSv/h. Due to the scattering and shielding effects, the deviation of the attenuation rate from the inverse-square law was observed and the isodose lines exhibited spatial drift. Measured dose rates at key points showed good agreement with the simulation result, with a maximum deviation within 30%. Conclusions:The complex radiation field distribution can be effectively simulated using Geant4 in an e-FLASH treatment room. This indicated the Geant4 is not only applicable for the shielding calculations in e-FLASH radiotherapy facilities, but also for the design optimization through, reduction of trial-and-error iterations and engineering costs.
3.Research progress on the role of ferroptosis in infectious diseases
Linzhi YUE ; Tao MA ; Yumei DAI ; Wenya DU ; Guofu WANG ; Lixian WU
Chinese Journal of Comparative Medicine 2024;34(7):175-180
Ferroptosis is a newly discovered mode of programmed cell death characterized by the accumulation of intracellular iron-dependent lipid peroxidation.Current research has mainly focused on the role of ferroptosis in the field of cancer,but increasing evidence shows that ferroptosis is also related to the occurrence of infectious diseases.Ferroptosis has accordingly been detected in cases of COVID-19,tuberculosis,and cryptococcal meningitis,as well as other diseases.This article reviews the role of ferroptosis in infectious diseases,to provide new ideas for the prevention and treatment of ferroptosis-related infectious diseases.
4.Effects of pulsed electron beams with ultra-high dose rate and conventional dose rate on Caenorhabditis elegans
Shuang WU ; Zhihui LI ; Wenxi YANG ; Guofu DONG ; Changzhen WANG
Chinese Journal of Radiological Medicine and Protection 2024;44(11):903-908
Objective:To explore the effects of ultra-high dose rate pulsed electron beams on Caenorhabditis elegans ( C. elegans). Methods:The adult wild-type strain (N2) of C. elegans was synchronized and cultured to L4 stage, and then randomly divided into control group (SHAM group), conventional radiotherapy dose rate group (CONV group) and ultra-high dose rate radiation group (UHDR group). The CONV and UHDR groups were exposed to 3 Gy of the pulsed electron beam at dose rates of 0.3 and 200 Gy/s, respectively. After irradiation, the egg-laying capacity of each group was assessed, and the developmental progress, motility, and survival rates each were evaluated at day 3, 6, and 10. Results:On the 3 rd day post-irradiation, both the CONV and UHDR groups showed shorter body lengths compared to the SHAM group ( t=4.81, 4.83, P<0.05), with no significant differences in body width ( P>0.05). On the 6 th and 10 th days, the CONV group showed a significant reduction in both body length and width compared to the SHAM group ( t=3.18-3.63, P<0.05), whereas the UHDR group displayed a significant increase in body length ( t=-9.85, -2.87, P<0.05) with no significant change in body width. When comparing the UHDR group to the CONV group on day 6 and 10, a significant increase in body width was observed ( t=-4.43, -3.37, P<0.05). Motor activity, including head swinging and body bending, significantly decreased in the CONV and UHDR groups compared to the SHAM group on day 6 ( t=2.91, 3.52, 3.97, 2.71, P<0.05), with no significant differences among the three groups by day 10 ( P>0.05). Egg-laying capacity significantly reduced in both irradiated groups compared to the SHAM group ( t=1.72, 5.54, P<0.05), while the UHDR group exhibited higher fecundity than the CONV group ( t=-5.99, P<0.05). Lifespan was significantly shortened in the CONV group compared to the SHAM group ( χ2=8.49, P<0.05), whereas the survival time of the UHDR group was not significantly differ from that of the SHAM group ( P>0.05). Conclusions:Exposure to a conventional electron beam result in developmental delays, reduced mobility, decreased fecundity, and a shortened lifespan in C. elegans. However, only slight side effects were observed when C. elegans were exposed to an ultra-high dose rate pulsed electron beam at the same dosage.
5.Mechanism of Buyang Huanwutang Combined with Bone Marrow Mesenchymal Stem Cell Transplantation in Treatment of Spinal Cord Injury Based on PI3K/Akt Signaling Pathway
Yang XU ; Chenglin WU ; Dehua GUO ; Yinzhen YU ; Guofu ZHANG
Chinese Journal of Experimental Traditional Medical Formulae 2023;29(4):9-17
ObjectiveTo explore the mechanism of Buyang Huanwutang combined with bone marrow mesenchymal stem cell (BMSC) transplantation in the treatment of spinal cord injury (SCI). MethodDifferent concentrations (12.5, 25, 50 g·kg-1) of Buyang Huanwutang were administrated to rats by gavage. The spinal cord function of rats was measured by modified Tarlov score, and the most suitable concentration of Buyang Huanwutang was screened out. SD rats were then divided into 6 groups, namely, the sham operation group (gavage of equal amount of normal saline), the model group (gavage of equal amount of normal saline), the Buyang Huanwutang group (gavage of 25 g·kg-1 Buyang Huanwutang), the BMSC transplantation group (tail vein injection of BMSCs 1 mL), the Buyang Huanwutang+BMSC group (gavage of 25 g·kg-1 Buyang Huanwutang and tail vein injection of BMSCs 1 mL), the Buyang Huanwutang+BMSC+LY294002 group (gavage of 25 g·kg-1 Buyang Huanwutang and tail vein injection of BMSCs 1 mL and 40 mg·kg-1 LY294002), with 10 rats in each group. The spinal cord function was measured by the modified Tarlov score, inclined plate test, and latency of cortical somatosensory evoked potential. Immunohistochemistry was used to detect the number of 5-bromo-2-deoxyuracil nucleoside (Brdu)-labeled positive cells in the spinal cord tissue. The protein expression levels of phosphorylated protein kinase B (p-Akt), glycoprotein 130 (gp130), and interleukin-6 (IL-6) in spinal cord were detected by Western blot. ResultAs compared with the sham operation group, the Tarlov score and the critical angle of tilt plane in the model group were significantly decreased (P<0.05), and the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt, gp130, and IL-6 were significantly increased (P<0.05). As compared with the model group, the Tarlov score and the critical angle of tilt plane in the sham operation group and each treatment group were significantly increased (P<0.05), and the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt, gp130, and IL-6 were significantly decreased (P<0.05). As compared with the BMSC group, the Tarlov score and the critical angle of inclined plane in the Buyang Huanwutang+BMSC group increased (P<0.05), the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt, gp130, and IL-6 decreased (P<0.05), and the number of Brdu-labeled positive cells increased 5 weeks after transplantation (P<0.05). As compared with the Buyang Huanwutang+BMSC group, the Tarlov score and the critical angle of the inclined plane in the Buyang Huanwutang+BMSC+LY294002 group increased (P<0.05), and the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt, gp130, and IL-6 decreased significantly (P<0.05). Five weeks after transplantation, the number of Brdu-labeled positive cells increased significantly in the Buyang Huanwutang+BMSC+LY294002 group (P<0.05). ConclusionBuyang Huanwutang can promote BMSCs migration and restore spinal cord function by inhibiting phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signal.
6.Effect of Calycosin-mediated GP130/JAK/STAT Signaling Pathway on Oxidative Injury of Astrocytes in Spinal Cord
Dehua GUO ; Xiaozhou LIU ; Chenglin WU ; Yang XU ; Guofu ZHANG
Chinese Journal of Experimental Traditional Medical Formulae 2022;28(18):54-61
ObjectiveTo investigate the effect of calycosin-mediated glucoprotein130/Janus kinase/signal transducer and activator of transcription factor (GP130/JAK/STAT) signaling pathway on oxidative injury of astrocytes in spinal cord. MethodAstrocytes in rat spinal cord were isolated and identified by immunofluorescence detection of glial fibrillary acidic protein (GFAP). The cells were respectively pre-treated with 5, 10, 20 μmol·L-1 calycosin for 12 h, and then 100 μmol·L-1 H2O2 (24 h) was added to induce oxidative injury. Cell counting kit-8 (CCK-8) assay was employed to detect cell proliferation and select the optimal concentration of calycosin. The following experimental groups were designed: control group, model group (100 μmol·L-1 H2O2), calycosin group (20 μmol·L-1 calycosin), calycosin + LY294002 group (20 μmol·L-1 calycosin + 10 μmol·L-1 LY294002), and calycosin + Stattic group (20 μmol·L-1 calycosin + 3 μmol·L-1 Stattic). CCK-8 assay and immunofluorescence method were used to detect the proliferation of cells and flow cytometry was applied to detect cell apoptosis and cycle. The protein expression of phosphorylated (p)-JAK2, p-STAT3, p-protein kinase B (Akt), GP130, and interleukin-6 (IL-6) was detected by Western blotting. ResultCompared with the control group, the model group showed low proliferation activity and high apoptosis rate of cells (P<0.05). Compared with the model group, calycosin (20 μmol·L-1) group displayed high proliferation activity and low apoptosis rate of cells (P<0.05). Compared with calycosin (20 μmol·L-1) group, both phosphatidylinosirtol-3-kinases (PI3K) inhibitor LY294002 and STAT3 inhibitor Stattic significantly reduced the proliferation activity and increased the apoptosis rate of cells (P<0.05). The protein expression of p-JAK2, p-STAT3, p-Akt, GP130, and IL-6 in the model group was higher than that in the control group (P<0.05), and the expression of the above indicators was lower in each treatment group than in the model group (P<0.05). ConclusionCalycosin can promote the proliferation and inhibit the apoptosis of astrocytes with oxidative injury by inhibiting the phosphorylation of PI3K/Akt pathway and JAK2/STAT3 pathway.
7.Screening and functional studies of long non - coding RNA in protecting ischemic acute kidney injury by Astragaloside Ⅳ
Yazhen WANG ; Jihuan DAI ; Genxiang MAO ; Qing WU ; Guofu WANG
Chinese Journal of Primary Medicine and Pharmacy 2019;26(6):687-692
Objective To investigate the expression profile of long non - coding RNAs(lncRNAs) in acute kidney injury (AKI) rats upon astragaloside IV(AS - IV) treatment. Methods Eight male SD rats were selected and randomly divided into two groups. AKI model group(group 1):4 rats were subjected to ischemia - reperfusion(I/ R);AS - Ⅳ pretreatment group (group 2):4 rats were orally administered AS - Ⅳ for 7 days prior to I/ R. Renal tissues were collected after I/ R treatment of 24h,total RNA was extracted from renal tissues and tested for quality. Sequencing experiments were carried out after being qualified. The threshold set for up - and down - regulated genes was a fold change(group1 / group2)≥2 and P≤0. 05. Afterwards,GO analysis and KEGG analysis were used to determine the roles that these differentially expressed mRNAs played in these GO terms or pathways. Results Two hundred and thirty - two lncRNAs were differentially expressed(127 lncRNAs were up - regulated and 105 lncRNAs were down -regulated). Three hundred and forty - one mRNAs were differentially expressed(178 mRNAs were up - regulated and 163 mRNAs were down - regulated). GO analysis indicated that differentially expressed mRNAs were mainly involved in biological processes such as nucleosome assembly,chromatin assembly,nucleosome organization,chromatin assembly or disassembly and DNA conformation change. GO analysis indicated that differentially expressed mRNAs were mainly involved in cellular components such as nucleosome,protein - DNA complex,nuclear chromatin,chromatin and nuclear nucleosome. GO analysis indicated that differentially expressed mRNAs were mainly involved in molecular functions such as protein heterodimerization activity,protein dimerization activity,DNA binding,nucleic acid binding. Signal pathway analysis indicated that lncRNAs and mRNAs were involved in systemic lupus erythematosus,alcoholism and viral carcinogenesis. Conclusion LncRNAs expression differed significantly in renal tissues of AKI model group and AS - Ⅳ preconditioning group. Study of the biological functions and pathways of these lncRNAs indicated that they may be involved in the mechanism of AS - Ⅳ ameliorated ischemic acute renal injury.
8.Feasibility study of in vivo fingernail dosimetry by electron paramagnetic resonance
Ye TIAN ; Junwang GUO ; Jierui ZOU ; Lei MA ; Guofu DONG ; Jianbo CONG ; Ke WU
Chinese Journal of Radiological Medicine and Protection 2019;39(5):392-396
Objective To explore the feasibility of EPR in vivo fingernail dosimetry to address the difficulty in separating mechanically induced signals from fingernail EPR dosimetry for need of nuclear medical emergency aid.Methods Using the specially designed EPR in vivo measurement system,uncut fingernails were measured to obtain the characteristics of EPR signal without mechanically induced signals.The in vivo fingernail experiment was carried out to evaluate the impact of in vivo condition on the spectra.Actual in vivo measurement experiment was conducted to evaluate the interference of the in vivo condition on EPR spectra.Results The background signal distribution of uncut fingernails was obtained and background signals had no significant difference between male and female(P>0.05).The dose response curve in the range of 2-10 Gy was established,and the half-life of the fingernail radiation-induced signal was approximately 5 d.The water treatment combined with temperature-changing was established for restoring the background signal.EPR signal obtained after restoring treatment has no significant difference with background signal (P> 0.05).The EPR spectra of in vivo fingernails were obtained.Conclusions The EPR spectra without mechanically induced signals can be acquired by this method.The feasibility of the in vivo fingernail EPR dosimetry is preliminarily verified.
9.ADC measurement in assessment of tumor grade and myometrial invasion of endometrial carcinoma
Jia LIU ; Shijia WANG ; Guofu ZHANG ; Fenghua MA ; Xiaomei TIAN ; Dongyan WANG ; Yanyu ZHANG ; Shouxin GU ; Minjie WU
Journal of Practical Radiology 2018;34(12):1893-1897
Objective To investigate the value of the apparent diffusion coefficient (ADC)measurement in assessment of tumor grade and myometrial invasion of endometrial carcinoma (EC).Methods 80 EC patients and 28 cervical cancer patients with normal endometrium were studied retrospectively.1.5T conventional MRI and DWI (b=0,1 000 s/mm2)were performed,and ADC values were calculated by two radiologists.Statistical analyses were performed by using SPSS 19.0 and Medcalc software.Results The mean ADC values (×10-3mm2/s)were 0.851±0.131,0.752±0.099,0.681±0.089 for G1,G2 and G3 EC,respectively.Significant statistical differences were achieved for the three groups (G1 vs G2:P=0.005;G2 vs G3:P=0.03;G1 vs G3:P< 0.000 1).For the prediction of G3,the area under the curve (AUC)of 0.851 and the cut-off value of ≤0.742×10-3mm2/s were identified,with the sensitivity, specificity and accuracy of 88.24%,76.19% and 85%,respectively.Conclusion There are significant statistical differences between histologic grades of EC.ADC measurement may have the potential to select G3 EC patients.
10.Intraoperative obeservation of laparoscopic splenectomy assisted with splenic artery embolization in patients with hypersplenism secondary to portal hypertension and splenomegaly
Pengfei JIN ; Huawen WU ; Dexi JIN ; Guofu CHEN
Chinese Journal of Postgraduates of Medicine 2018;41(12):1090-1093
Objective To discuss introperative value of laparoscopic splenectomy (LS) treatment assisted with preoperative splenic artery embolization (SAE) in the patients with the hypersplenism secondary to portal hypertension and splenomegaly. Methods The clinical data of 38 patients with the hypersplenism secondary to portal hypertension and splenomegaly admitted to the First People′s Hospital of Wenling from April 2015 to April 2018 were analyzed. Among them, 21 patients underwent LS alone (alone group) and 17 patients underwent LS assisted with preoperative SAE (combined group). Including length of the spleen and liver function Child-Pugh grade, operative time, blood transfusion rate, intraoperative blood loss, intraoperative blood transfusion volume and conversion rate were compared between two groups. Then the clinical value of LS treatment assisted with preoperative splenic artery embolization was discussed. Results The splenic volume of combined group was significantly reduced after SAE: (627 ± 195) cm3vs. (998 ± 251) cm3, P<0.05. The conversion rate was 23.8%(5/21) in alone group, while no patient required open surgery in the combined group. Compared with that in alone group, operative time of the combined group was shorter [(143 ± 27) min vs. (189 ± 33) min], the blood loss volume was less [(155 ± 49) ml vs. (302 ± 76) ml)], and the differences were statistically significant (P< 0.05). The blood transfusion rates of combined group was lower [2/17 vs. 33.3% (7/21)], and intraoperative blood transfusion volume was less [(192 ± 42) ml vs. (399 ± 87) ml] . The differences were statistically significant (P<0.05). Conclusions LS treatment assisted with preoperative SAE has some advantages, such as shorter operative time, lower surgical laparotomy rate, less intraoperative blood transfusion, less bleeding and shorter length of stay.

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