Objective:To analyze the influence of magnetic field on the proton beam delivery and dose distribution, and develop a correction method for the Bragg peak (BP) shift under the vertical magnetic field, providing reference for the dose calculation and beam delivery of MRI-guided proton therapy.Methods:Monte Carlo (MC) simulation was used to study the dose distribution of the proton beam in the water phantom under the magnetic field. The BP location was corrected by the method of" angle correction+ energy correction" , and the correction parameters were calculated by the analytical formula based on the simulation data.Results:The magnetic field caused the dose distortion and shift of BP location. The shift degree was increased with the increase of field strength and initial energy. Compared with MC simulation, the result of calculating proton deflection in the air by the analytical method yielded a deviation within 0.2%. Based on the simulation data and calculation formulas, the correction parameters under different conditions could be calculated within 1 s by using the MATLAB programming. The calculation results showed that the air layer with magnetic field, isocenter depth, irradiation direction exerted different influence on the correction parameters. After correction, the BP location was basically consistent with the expected (offset ≤0.2 mm).Conclusions:The BP shift under the vertical magnetic field can be effectively corrected by " the angle correction+ energy correction" method. The correction parameters under different conditions can be quickly and accurately calculated by the calculation formulas based on simulation data.

Objective:To develop and validate the accuracy of an independent dose calculation toolkit for the horizontal beamline of Shanghai Advanced Proton Therapy (SAPT) facility based on an open-source dose calculation engine.Methods:Machine data, such as absolute integral depth doses (IDDs) and lateral profiles in air were measured and lateral profiles in water were derived by Monte-Carlo simulations. The dose computation models for SAPT horizontal beamline pencil beams in water were achieved by combining machine data and dose calculation engine. The verification of the dose reconstruction toolkit included absolute dose verification and relative dose verification. The absolute dose verification is performed to mainly compare the reconstructed value and the measured value at different depths along the center axis of the beam direction of a cube plan. The relative dose verification is conducted to mainly compare the lateral profile or two-dimensional dose distribution between the measured value and the reconstructed value. Meanwhile, the precision of double-gaussian and single-gaussian lateral beam models was compared.Results:The deviations of the absolute dose between the calculated and measured values were basically within 2%. The deviations of 20%-80% penumbra between the measured and the calculated values were within 1 mm, and deviations of the full width at half height were within 2 mm. For 3 cube plans and 2 clinical cases, the two-dimensional gamma pass rates (3 mm/3%) between the measured and calculated dose distributions at the corresponding depths were greater than 95%. The double-gaussian lateral beam model was more accurate in the high dose gradient region and deeper depth.Conclusion:The precision of independent dose calculation toolkit is acceptable for clinical requirements, which can be employed to investigate other dose-related issues.

Objective:To compare the postoperative liver function injury condition in patients with intermediate-and advanced-stage hepatocellular carcinoma (HCC) treated with hepatic artery infusion chemotherapy (HAIC) and hepatic artery chemoembolization (TACE) combined with immune checkpoint inhibitors (ICIs) and multi-target tyrosine kinase inhibitors (TKIs).Methods:Patients with intermediate-and advanced-stage HCC who were admitted and treated with HAIC/TACE+ICIs+TKIs therapy at Nanfang Hospital of Southern Medical University from January 2019 to November 2021, with follow-up up to July 2023, were retrospectively enrolled. The results of liver function tests within one week before interventional surgery and on the first day after surgery were recorded. The degree of postoperative liver injury was graded according to the common terminology criteria for adverse events 5.0 (CTCAE 5.0). The treatment efficacy was evaluated according to RECIST 1.1 criteria. Measurement data were compared between groups using a t-test or a non-parametric rank sum test. Enumeration data were compared between the groups using the χ2 test or Fisher's exact probability method. The survival condition differences were analyzed by the log-rank method. Results:This study included 82 and 77 cases in the HAIC and TACE groups. There were no statistically significant differences between the two groups of patients in terms of gender, age, physical condition score, number of tumors, presence or absence of liver cirrhosis, Child-Pugh grade, albumin-bilirubin (ALBI) grade, and combined ICIs and TKIs . The HAIC group had later tumor staging, a greater tumor burden, poorer liver reserve function, and a larger proportion of patients in stage C (81.7% vs. 63.6%), χ2=6.573, P = 0.01). There were 53 cases (64.6% vs. 32.5%) with a maximum tumor diameter of ≥ 10cm, χ2=16.441, P < 0.001), and more patients had a retention rate of ≥ 10% for indocyanine green (ICG) at 15 minutes (68.3% vs. 51.9%, P = 0.035). The postoperative incidence rate of increased levels of alanine aminotransferase, aspartate aminotransferase, and total bilirubin was significantly lower in the HAIC group than that in the TACE group (28.0% vs. 63.6%, χ2=20.298, P < 0.001, 54.9% vs. 85.7%, χ2=17.917, P < 0.001;40.2% vs. 55.8%, χ2=3.873, P = 0.049). The number of patients with postoperative ALBI grade 3 was significantly lower in the HAIC group than that in the TACE group (6.1% vs. 16.9%, χ2=4.601, P = 0.032). There was no statistically significant difference in the incidence rate of postoperative hypoalbuminemia, activated partial thromboplastin time, or increased international standardized ratio between the two groups of patients. There was no statistically significant difference in median progression-free survival (7.3 months vs. 8.2 months, P = 0.296) or median overall survival (16.5 months vs. 21.9 months, P = 0.678) between the two groups of patients. Conclusion:The incidence rate of postoperative liver injury is higher in patients with intermediate-and advanced-stage HCC treated with TACE combined with ICIs and TKIs than in patients with HAIC combined with ICIs and TKIs.

Objective:To explore the rapid evaluation of the early pathogen of severe Chlamydophila psittaci pneumonia by bedside diagnostic bronchoscopy, so as to start effective anti-infection treatment before the results of macrogenome next generation sequencing (mNGS) test. Methods:The clinical data of three patients with severe Chlamydophila psittaci pneumonia who were successfully treated in the First Affiliated Hospital of Xinjiang Medical University, the First People's Hospital of Aksu District, and the First Division Hospital of Xinjiang Production and Construction Corps from October 2020 to June 2021 were retrospectively analyzed, including the rapid assessment of early pathogens by bedside diagnostic bronchoscopy and the use of antibiotics to start anti-infection treatment. These patients were successfully treated. Results:The three patients were male, aged 63, 45 and 58 years old, respectively. Before the onset of the penumonia, they had a clear medical history of bird exposure. The clinical manifestations mainly included fever, dry cough, shortness of breath and dyspnea. One case had abdominal pain and lethargy. The results of laboratory examination indicated that the peripheral blood white blood cell count (WBC) of two patients were high [(10.2-11.9)×10 9/L], the percentage of neutrophils increased (85.2%-94.6%) and the percentage of lymphocytes decreased (3.2%-7.7%) in all 3 patients after admission to hospital and entering into intensive care unit (ICU). The procalcitonin (PCT) of 3 patients increased after admission, and still increased when entering ICU (0.3-4.8 ng/L), so did C-reactive protein (CRP, 58.0-162.0 mg/L) and erythrocyte sedimentation rate (ESR, 36.0-90.0 mm/1 h). After admission, serum alanine transaminase (ALT) increased in 2 cases (136.7 U/L, 220.5 U/L), so did aspartate transaminase (AST) in 2 cases (249.6 U/L, 164.2 U/L). ALT (162.2-267.9 U/L) and AST (189.8-223.2 U/L) increased in 3 patients when they entered ICU. The level of serum creatinine (SCr) of 3 patients were normal after admission and entering ICU. The chest computed tomography (CT) findings of 3 patients were acute interstitial pneumonia, bronchopneumonia and lung consolidation, of which 2 cases were accompanied by a small amount of pleural effusion, and 1 case was accompanied by more regular small air sacs. Multiple lung lobes were involved, but mainly one lung lobe. The oxygenation index (PaO 2/FiO 2) of the 3 patients admitting to ICU were 100.0, 57.5 and 105.4 mmHg (1 mmHg ≈ 0.133 kPa), respectively, which met with the diagnostic criteria of moderate and severe acute respiratory distress syndrome (ARDS). All three patients received endotracheal intubation and mechanical ventilation. Under the bedside bronchoscope, the bronchial mucosa of 3 patients were obviously congested and edematous, without purulent secretion, and there was 1 case with mucosal hemorrhage. Three patients underwent bedside diagnostic bronchoscopy, and the evaluation result of the pathogen was that it might be atypical pathogen infection, so they were given moxifloxacin, cisromet and doxycycline intravenously, respectively, and combined with carbapenem antibiotics intravenously. After 3 days, the detection results of mNGS in bronchoalveolar lavage fluid (BALF) showed that only Chlamydia psittaci was infected. At this time, the condition was significantly improved, and PaO 2/FiO 2 was significantly increased. Therefore, the antibiotic treatment scheme remained unchanged, and mNGS only served to verify the initial diagnosis. Two patients were extubated on the 7th and 12th day of admission to the ICU, respectively, while one patient was extubated on the 16th day of admission to the ICU due to nosocomial infection. All 3 patients were transferred to the respiratory ward after the condition was stable. Conclusion:The bedside diagnostic bronchoscopy based on clinical characteristics is conducive to not only the rapid assessment of the early pathogens of severe Chlamydia psittaci pneumonia, but also effective anti-infection treatment before the returning of mNGS test results, which can make up for the lag and uncertainty of the mNGS test results.

Background: Dysregulation of intestinal flora is a key risk factor for colorectal cancer (CRC). In recent years, traditional Chinese medicine preparations and probiotics have been increasingly applied in the prevention of CRC. Aims: To investigate the preventive effect of Panax notoginseng saponins (PNS) combined with Bacillus subtilis on CRC. Methods: Thirty female BALB/c mice were randomly divided into normal control group (NC group), model group, PNS group, Bacillus subtilis group and PNS combined with Bacillus subtilis group (PaB group). CRC mice model was constructed by azoxymethane (AOM)/dextran sulfate sodium (DSS) method. During the experiment, the mice were weighed, and disease activity index (DAI) score was evaluated. The length of colorectum and tumor number were measured. Serum interleukin (IL) - 6 and IL - 10 contents were determined by ELISA. 16S rRNA sequencing was used to analyze the composition of intestinal flora. Results: Compared with model group, DAI score was significantly decreased (P<0.001), colorectal length was significantly increased (P<0.001), number of tumor was significantly decreased (P<0.001), tumor volume was significantly decreased (P<0.01), serum IL-6 content was significantly decreased (P<0.000 1), and serum IL-10 content was significantly increased in PaB group (P<0.000 1). The results of intestinal flora sequencing showed that Simpson index was significantly decreased in PaB group than in model group (P<0.05), Shannon index and Chao index were significantly increased (P<0.05), abundance of Bacteroidota was significantly increased (P<0.01), abundances of Firmicutes, Helicobacter and Oscillibacter were significantly decreased (P all <0.05), abundance of Lactococcus was significantly increased (P<0.05). Conclusions: The combination of PNS and Bacillus subtilis can effectively alleviate the occurrence of CRC caused by AOM/DSS, and its mechanism may be related to the improvement of composition of intestinal microbial community.

Objective:To analyze the serum anti-Müllerian hormone (AMH) levels in women of childbearing age in different age groups in Henan, and establish the medical reference intervals based on measurement results from this population.Methods:From January to June 2017, 620 healthy women of childbearing age (20-34 years old), who underwent pre-pregnancy eugenics and pre-marital checkups in 13 project sites in Henan, were included in this study. Participants were divided into 3 age groups: 20-24 years group ( n=210), 25-29 years group ( n=207), and 30-34 years group ( n=203). Spearman correlation coefficient was used to evaluate the correlation between serum AMH level and age; Kruskal-Wallis H test was used to compare the serum AMH levels of different age groups; Wilcoxon test was used for comparison between pairs; the percentile method ( P2.5, P97.5) was used to establish medical reference interval of serum AMH in women of childbearing age for the whole population and different age groups, respectively. Results:The correlation coefficient between serum AMH and age in women of childbearing age (20-34 years old) is -0.17 ( P<0.001). There was a statistically significant difference in the overall frequency distribution of serum AMH levels among the three different age groups ( H=21.978, P<0.05). Among them, there is a statistically significant difference between the 20-24 years group and the 30-34 years group ( Z=4.292, P<0.05). There is a statistically significant difference between the 25-29 years group and the 30-34 years group ( Z=3.803, P<0.05). The reference range of serum AMH is 0.281-9.693 μg/L in this cohort; the reference range of serum AMH is 0.524-10.760, 0.229-9.200, 0.115-8.200 μg/L for women of childbearing age at 20-24, 25-29 and 30-34 years, respectively. Conclusion:The serum AMH level of women of childbearing age (20-34 years old) decreases with age. It is of great significance to establish the serum AMH reference interval for women of childbearing age in different age groups in Henan.