1.Monte Carlo simulation study of the effect of filter on radiotherapy dosimetry in superficial X-ray therapy apparatus
Li TAO ; Hui ZHANG ; Yikai WU ; Junyi LIU ; Miao QI ; Ning GAO ; Yankui CHANG ; Xi PEI ; Zhi CHEN ; Xie XU
Chinese Journal of Radiological Medicine and Protection 2025;45(3):194-201
Objective:To explore the dosimetry optimization strategy based on filter thickness and shape selection for the bulb superficial X-ray radiotherapy unit.Methods:Monte Carlo code TOPAS was used to model tubular equipment, and the dose distribution from six X-ray energies (50-150 kV) and five conventional aluminum filters (0.5-3.0 mm) with different thickness were simulated in the water model. The percentage depth dose (PDD) curve along the central axis, the center-axis profile dose at different depths, and the lateral dose distribution were analyzed. The dose distribution of three different designs of aluminum filters (conventional cylindrical, conical and oblique cylindrical filters) was compared to evaluate the effect of dosimetric optimization of different filter shapes.Results:Under the same energy, increasing the thickness of the filter can optimize the superficial skin dose, and the optimization effect of depth dose uniformity can be increased by 26% at a depth of 5.5 mm at 70 kV energy. The raised, flat and inclined dose distribution modes can be achieved by using conventional cylindrical, conical and inclined aluminum filters.Conclusions:By selecting the appropriate X-ray energy and filter thickness, an ideal dose distribution matching the tumor depth can be achieved. The application of personalized filters is also of great significance for diverse target areas.
3.Monte Carlo study of transmission X-ray tubes in kilovoltage radiotherapy
Yikai WU ; Zhongyu QI ; Li TAO ; Hui ZHANG ; Zeeshan MUHAMMAD ; Zirui YE ; Yankui CHANG ; Xi PEI ; Xu GEORGE
Chinese Journal of Medical Physics 2025;42(7):863-871
Transmission X-ray tubes are relatively new devices characterized by portability,suitability for miniaturization,and low requirements for shielding,making them ideal radiation sources for kilovoltage X-ray therapy.However,their application in radiotherapy remains underexplored.An electron target model of a transmission X-ray tube is developed using the Monte Carlo toolkit TOPAS 3.8.1.The study investigates the effect of tungsten target thickness on X-ray output efficiency,finding that a tube voltage of 50 kV and a tungsten thickness of 1.4 μm yields the highest emission efficiency.Based on the energy spectrum at this optimal efficiency,polynomial fitting approach is applied to determine the corresponding aluminum filter thickness for mean energies ranging from 20 keV to 35 keV,achieving a mean fitting error of 0.91%.Next,the study simulates dose deposition in a water phantom for spectra with different mean energies and various source-to-surface distances,and plots percent-depth-dose curves,relative normalized dose-depth curves,and relative normalized dose histograms under each treatment condition.Finally,the simulated results are compared with experimental data from the intraoperative radiotherapy system Intrabeam and the superficial X-ray therapy unit SRT-100,obtaining average relative errors of 3.71%and 4.38%,respectively.These findings provide a theoretical foundation for further optimization of transmission X-ray tubes in kilovoltage radiotherapy.
4.Energy efficiency of contrast-enhanced ultrasound combined with TERT promoter mutation to construct a nomogram model for the prediction of concomitant cervical lymph node metastasis in PTMC
Chang-hui WU ; Zhiping HUANG ; Huiping DAI ; Huifang QIU ; Chun HE ; Fang TANG
The Journal of Practical Medicine 2025;41(5):756-765
Objective The study aimed to investigate the predictive efficacy of contrast-enhanced ultrasound combined with telomerase reverse transcriptase(TERT)promoter mutation in constructing nomogram model for the prediction of concomitant cervical lymph node metastasis(CLNM)in papillary thyroid microcarcinoma(pTMC).Methods A total of 202 patients with pTMC who underwent partial or total thyroidectomy+lymph node dissection at our hospital from January 2021 to March 2024 were selected.Then,they were divided into the CLNM group(97 patients)and the non-CLNM group(105 patients)according to whether they had concomitant CLNM on postoperative pathological examination.General data and ultrasound(conventional ultrasound and contrast-enhanced ultrasound)characteristics were collected from all patients with pTMC,and Sanger sequencing was used to detect TERT promoter mutations.The influencing factors of pTMC complicated by CLNM were analyzed by single-factor and multifactorial unconditional logistic regression;the nomogram model of pTMC complicating CLNM with contrast-enhanced ultra-sound combined with TERT promoter mutation was constructed by RStudio 4.4.1 software,and the consistency and net benefit of the nomogram model were evaluated by using calibration curves,decision curves,and C-indexes,and the Hosmer-Lemeshow test for goodness of fit of the nomogram model;The predictive efficiency of the nomogram model constructed by combining contrast-enhanced ultrasound and TERT promoter mutation for pTMC complicated by CLNM was evaluated by plotting receiver operating characteristic(ROC)curves using MedCalc22.023 software.Results After postoperative pathological examination,the incidence of CLNM in 202 patients with pTMC was 48.02%(97/202).Univariate analysis showed that thyroglobulin antibodies,number of lesions,aspect ratio,micro-calcifications,enhancement time,enhancement mode,enhancement intensity,capsular continuity,and TERT promoter mutations were associated with pTMC complicating CLNM(P<0.05).Multifactorial unconditional logistic regression showed that multifocal tumours(OR=3.487,95%CI:1.641~7.406,P=0.001),microcalcifications(OR=4.484,95%CI:2.113~9.516,P<0.001),equal or high enhancement(OR=3.187,95%CI:1.460~6.957,P=0.004),disruption of peritoneal continuity(OR=2.201,95%CI:1.051~4.608,P=0.036),and TERT promoter mutation positivity(OR=4.460,95%CI:2.132~10.103,P<0.001)were the independent risk factors for pTMC complicating CLNM.A contrast-enhanced ultrasound combined TERT promoter mutation nomogram model was constructed based on independent risk factors for pTMC complicating CLNM[Logit(p)=-4.486+1.350×number of foci+1.399×microcalcifications+2.124×intensity of enhancement+1.524×capsular continuity+2.175×TERT promoter mutations].The C-index of this nomogram model was 0.899(95%CI:0.893~0.905),the calibra-tion curve alignment was close to the ideal curve,the decision curve was higher than the two extreme curves,and the Hosmer-Lemeshow test showed a P>0.05.The ROC curve analysis showed that the nomogram model constructed with contrast-enhanced ultrasound combined with TERT promoter mutations predicted CLNM in pTMC with an area under the curve of 0.899.This was significantly higher than the area under the curves for contrast-enhanced ultra-sound alone(0.857)and TERT promoter mutations alone(0.697)(P<0.05).Conclusion The contrast-enhanced ultrasound combined with TERT promoter mutations to construct a nomogram model has high predictive efficiency for pTMC complicating CLNM.
6.Comprehensive Analysis of Oncogenic, Prognostic, and Immunological Roles of FANCD2 in Hepatocellular Carcinoma: A Potential Predictor for Survival and Immunotherapy.
Meng Jiao XU ; Wen DENG ; Ting Ting JIANG ; Shi Yu WANG ; Ru Yu LIU ; Min CHANG ; Shu Ling WU ; Ge SHEN ; Xiao Xue CHEN ; Yuan Jiao GAO ; Hongxiao HAO ; Lei Ping HU ; Lu ZHANG ; Yao LU ; Wei YI ; Yao XIE ; Ming Hui LI
Biomedical and Environmental Sciences 2025;38(3):313-327
OBJECTIVE:
Hepatocellular carcinoma (HCC) is sensitive to ferroptosis, a new form of programmed cell death that occurs in most tumor types. However, the mechanism through which ferroptosis modulates HCC remains unclear. This study aimed to investigate the oncogenic role and prognostic value of FANCD2 and provide novel insights into the prognostic assessment and prediction of immunotherapy.
METHODS:
Using clinicopathological parameters and bioinformatic techniques, we comprehensively examined the expression of FANCD2 macroscopically and microcosmically. We conducted univariate and multivariate Cox regression analyses to identify the prognostic value of FANCD2 in HCC and elucidated the detailed molecular mechanisms underlying the involvement of FANCD2 in oncogenesis by promoting iron-related death.
RESULTS:
FANCD2 was significantly upregulated in digestive system cancers with abundant immune infiltration. As an independent risk factor for HCC, a high FANCD2 expression level was associated with poor clinical outcomes and response to immune checkpoint blockade. Gene set enrichment analysis revealed that FANCD2 was mainly involved in the cell cycle and CYP450 metabolism.
CONCLUSION
To the best of our knowledge, this is the first study to comprehensively elucidate the oncogenic role of FANCD2. FANCD2 has a tumor-promoting aspect in the digestive system and acts as an independent risk factor in HCC; hence, it has recognized value for predicting tumor aggressiveness and prognosis and may be a potential biomarker for poor responsiveness to immunotherapy.
Humans
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Carcinoma, Hepatocellular/diagnosis*
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Liver Neoplasms/diagnosis*
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Immunotherapy
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Fanconi Anemia Complementation Group D2 Protein/metabolism*
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Prognosis
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Male
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Female
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Middle Aged
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Biomarkers, Tumor/metabolism*
7.Mechanism of Euphorbiae Ebracteolatae Radix processed by milk in reducing intestinal toxicity.
Chang-Li SHEN ; Hao WU ; Hong-Li YU ; Hong-Mei WEN ; Xiao-Bing CUI ; Hui-Min BIAN ; Tong-la-Ga LI ; Min ZENG ; Yan-Qing XU ; Yu-Xin GU
China Journal of Chinese Materia Medica 2025;50(12):3204-3213
This study aimed to investigate the correlation between changes in intestinal toxicity and compositional alterations of Euphorbiae Ebracteolatae Radix(commonly known as Langdu) before and after milk processing, and to explore the detoxification mechanism of milk processing. Mice were intragastrically administered the 95% ethanol extract of raw Euphorbiae Ebracteolatae Radix, milk-decocted(milk-processed), and water-decocted(water-processed) Euphorbiae Ebracteolatae Radix. Fecal morphology, fecal water content, and the release levels of inflammatory cytokines tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β) in different intestinal segments were used as indicators to evaluate the effects of different processing methods on the cathartic effect and intestinal inflammatory toxicity of Euphorbiae Ebracteolatae Radix. LC-MS/MS was employed to analyze the small-molecule components in the raw product, the 95% ethanol extract of the milk-processed product, and the milky waste(precipitate) formed during milk processing, to assess the impact of milk processing on the chemical composition of Euphorbiae Ebracteolatae Radix. The results showed that compared with the blank group, both the raw and water-processed Euphorbiae Ebracteolatae Radix significantly increased the fecal morphology score, fecal water content, and the release levels of TNF-α and IL-1β in various intestinal segments(P<0.05). Compared with the raw group, all indicators in the milk-processed group significantly decreased(P<0.05), while no significant differences were observed in the water-processed group, indicating that milk, as an adjuvant in processing, plays a key role in reducing the intestinal toxicity of Euphorbiae Ebracteolatae Radix. Mass spectrometry results revealed that 29 components were identified in the raw product, including 28 terpenoids and 1 acetophenone. The content of these components decreased to varying extents after milk processing. A total of 28 components derived from Euphorbiae Ebracteolatae Radix were identified in the milky precipitate, of which 27 were terpenoids, suggesting that milk processing promotes the transfer of toxic components from Euphorbiae Ebracteolatae Radix into milk. To further investigate the effect of milk adjuvant processing on the toxic terpenoid components of Euphorbiae Ebracteolatae Radix, transmission electron microscopy(TEM) was used to observe the morphology of self-assembled casein micelles(the main protein in milk) in the milky precipitate. The micelles formed in casein-terpenoid solutions were characterized using particle size analysis, fluorescence spectroscopy, ultraviolet spectroscopy, and Fourier-transform infrared(FTIR) spectroscopy. TEM observations confirmed the presence of casein micelles in the milky precipitate. Characterization results showed that with increasing concentrations of toxic terpenoids, the average particle size of casein micelles increased, fluorescence intensity of the solution decreased, the maximum absorption wavelength in the UV spectrum shifted, and significant changes occurred in the infrared spectrum, indicating that interactions occurred between casein micelles and toxic terpenoid components. These findings indicate that the cathartic effect of Euphorbiae Ebracteolatae Radix becomes milder and its intestinal inflammatory toxicity is reduced after milk processing. The detoxification mechanism is that terpenoid components in Euphorbiae Ebracteolatae Radix reassemble with casein in milk to form micelles, promoting the transfer of some terpenoids into the milky precipitate.
Animals
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Mice
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Milk/chemistry*
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Drugs, Chinese Herbal/chemistry*
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Male
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Tumor Necrosis Factor-alpha/immunology*
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Intestines/drug effects*
;
Interleukin-1beta/immunology*
;
Tandem Mass Spectrometry
;
Female
8.Application of genome tagging technology in elucidating the function of sperm-specific protein 411 (Ssp411).
Xue-Hai ZHOU ; Min-Min HUA ; Jia-Nan TANG ; Bang-Guo WU ; Xue-Mei WANG ; Chang-Gen SHI ; Yang YANG ; Jun WU ; Bin WU ; Bao-Li ZHANG ; Yi-Si SUN ; Tian-Cheng ZHANG ; Hui-Juan SHI
Asian Journal of Andrology 2025;27(1):120-128
The genome tagging project (GTP) plays a pivotal role in addressing a critical gap in the understanding of protein functions. Within this framework, we successfully generated a human influenza hemagglutinin-tagged sperm-specific protein 411 (HA-tagged Ssp411) mouse model. This model is instrumental in probing the expression and function of Ssp411. Our research revealed that Ssp411 is expressed in the round spermatids, elongating spermatids, elongated spermatids, and epididymal spermatozoa. The comprehensive examination of the distribution of Ssp411 in these germ cells offers new perspectives on its involvement in spermiogenesis. Nevertheless, rigorous further inquiry is imperative to elucidate the precise mechanistic underpinnings of these functions. Ssp411 is not detectable in metaphase II (MII) oocytes, zygotes, or 2-cell stage embryos, highlighting its intricate role in early embryonic development. These findings not only advance our understanding of the role of Ssp411 in reproductive physiology but also significantly contribute to the overarching goals of the GTP, fostering groundbreaking advancements in the fields of spermiogenesis and reproductive biology.
Animals
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Female
;
Humans
;
Male
;
Mice
;
Spermatids/metabolism*
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Spermatogenesis/physiology*
;
Spermatozoa/metabolism*
;
Thioredoxins/genetics*
9.Emergency medical response strategy for the 2025 Dingri, Tibet Earthquake
Chenggong HU ; Xiaoyang DONG ; Hai HU ; Hui YAN ; Yaowen JIANG ; Qian HE ; Chang ZOU ; Si ZHANG ; Wei DONG ; Yan LIU ; Huanhuan ZHONG ; Ji DE ; Duoji MIMA ; Jin YANG ; Qiongda DAWA ; Lü ; JI ; La ZHA ; Qiongda JIBA ; Lunxu LIU ; Lei CHEN ; Dong WU
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(04):421-426
This paper systematically summarizes the practical experience of the 2025 Dingri earthquake emergency medical rescue in Tibet. It analyzes the requirements for earthquake medical rescue under conditions of high-altitude hypoxia, low temperature, and low air pressure. The paper provides a detailed discussion on the strategic layout of earthquake medical rescue at the national level, local government level, and through social participation. It covers the construction of rescue organizational systems, technical systems, material support systems, and information systems. The importance of building rescue teams is emphasized. In high-altitude and cold conditions, rapid response, scientific decision-making, and multi-party collaboration are identified as key elements to enhance rescue efficiency. By optimizing rescue organizational structures, strengthening the development of new equipment, and promoting telemedicine technologies, the precision and effectiveness of medical rescue can be significantly improved, providing important references for future similar disaster rescues.
10.Predictive value of dose-surface histogram for acute radiation proctitis in prostate cancer patients following radiotherapy
Xin ZHAO ; Mei-Liu YANG ; Xiao-Hui HAO ; Tian-Xiong WEI ; Qi ZHANG ; Hao-Yu CHANG ; Xiu-Xia WU
Medical Journal of Chinese People's Liberation Army 2025;50(1):44-49
Objective To evaluate the predictive value of dose-surface histogram(DSH)for radiation proctitis(RP)in prostate cancer(PCa)patients undergoing radiotherapy.Methods This prospective randomized controlled clinical trial included 380 PCa patients who underwent image-guided radiotherapy in the First Affiliated Hospital of Hebei Northern University from January 2018 to January 2023.Patients were randomly divided into observation group(n=200)and control group(n=180).The rectal dose distribution of patients in the two groups was evaluated by using DSH and dose-volume histogram(DVH),respectively.The receiver operating characteristic(ROC)curve was utilized to evaluate the predictive value of DSH for acute RP,with DVH serving as a reference.Results The difference was not statistically significant in clinical information such as age,KPS score,and body mass index(BMI)between the observation and control groups(P>0.05),as well as in acute RP incidence(P>0.05).There were significant differences in S40 and V40,S50 and V50,S60 and V60,S70 and V70,and S78 and V78 between the two groups(P<0.05).S40,S50,V40,and V50 showed low efficacy(P<0.001)in predicting acute RP at each level,with AUC≤0.700.S60 and V60 showed moderate efficacy(P<0.001)in predicting acute RP at each level,with AUC 0.700-0.900.S70,S78,V70 and V78 showed high efficacy(P<0.001)in predicting acute RP at each level,with AUC>0.900.Conclusions The predictive value of DSH for rectal toxicity in patients with PCa is basically consistent with that of DVH.It is expected to become a novel and valuable tool for evaluating radiotherapy plans in the future.

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