Objective:To explore the role of mechanical hemodynamic support (MHS) in mapping and catheter ablation of patients with hemodynamically unstable ventricular tachycardia (VT), report single-center experience in a cohort of consecutive patients receiving VT ablation during MHS therapy, and provide evidence-based medical evidence for clinical practice.Methods:This was a retrospective cohort study. Patients with hemodynamically unstable VT who underwent catheter ablation with MHS at Beijing Anzhen Hospital, Capital Medical University between August 2021 and December 2023 were included. Patients were divided into rescue group and preventive group according to the purpose of treatment. Their demographic data, periprocedural details, and clinical outcomes were collected and analyzed.Results:A total of 15 patients with hemodynamically unstable VT were included (8 patients in the rescue group and 7 patients in the preventive group). The acute procedure was successful in all patients. One patient in the rescue group had surgical left ventricular assist device (LVAD) implantation, remaining 14 patients received extracorporeal membrane oxygenation (ECMO) for circulation support. ECMO decannulation was performed in 12 patients due to clinical and hemodynamic stability, of which 6 patients were decannulation immediately after surgery and the remaining patients were decannulation at 2.0 (2.5) d after surgery. Two patients in the rescue group died during the index admission due to refractory heart failure and cerebral hemorrhage. During a median follow-up of 30 d (1 d to 12 months), one patient with LVAD had one episode of ventricular fibrillation at 6 months after discharge, and no further episodes of ventricular fibrillation and/or VT occurred after treatment with antiarrhythmic drugs. No malignant ventricular arrhythmia occurred in the remaining 12 patients who were followed up.Conclusions:MHS contributes to the successful completion of mapping and catheter ablation in patients with hemodynamically unstable VT, providing desirable hemodynamic status for emergency and elective conditions.

Iron is indispensable for the viablility of nearly all living organisms, and it is imperative for cells, tissues, and organisms to acquire this essential metal sufficiently and maintain its metabolic stability for survival. Disruption of iron homeostasis can lead to the development of various diseases. There is a robust connection between iron metabolism and infection, immunity, inflammation, and aging, suggesting that disorders in iron metabolism may contribute to the pathogenesis of arthritis. Numerous studies have focused on the significant role of iron metabolism in the development of arthritis and its potential for targeted drug therapy. Targeting iron metabolism offers a promising approach for individualized treatment of arthritis. Therefore, this review aimed to investigate the mechanisms by which the body maintains iron metabolism and the impacts of iron and iron metabolism disorders on arthritis. Furthermore, this review aimed to identify potential therapeutic targets and active substances related to iron metabolism, which could provide promising research directions in this field.

Objective To explore the correlation among P16INK4a expression,human papilloma virus(HPV)infection,and cervical intraepithelial neoplasia(CIN).Methods A total of 197 patients with CIN who visited our hospital between February 2020 and May 2023 were selected,including 62 with CIN1,89 with CIN2,and 46 with CIN3.At the same time,50 patients who underwent total hyste-rectomy and had normal cervical tissue confirmed by postoperative pathology were selected as the control group.P16INK4a expression and HPV infection were detected in each patient.Results The positive P16INK4a expression and HPV infection rates of the control group were 10.00% and 0.00%,respectively,significantly lower than those of patients with CIN(72.08% and 45.69%,respectively)(P<0.05).The positive P16INK4a expression rates of patients with CIN2 and CIN3 were 80.90% and 91.30%,respectively,significantly higher than that of patients with CIN1(45.16% )(P<0.05).The HPV infection rate among patients with CIN3 was 63.04%,significantly higher than those of patients with CIN1(33.87% )and CIN2(44.94% )(P<0.05).The positive P16INK4a expression rate of patients with CIN and HPV infec-tion was 93.33%,significantly higher than that of patients with CIN but without HPV infection(54.21% )(P<0.05).The positive P16INK4a expression rate of patients with HPV16/18 infection was 100.00%,significantly higher than that of patients with HPV31/33/53 infection(85.00% )(P<0.05).There was no statistically significant difference in the positive P16INK4a expression rate among patients with CIN by clinical characteristics such as age and body mass index(P>0.05).Conclusion The P16INK4a expression rate among patients with CIN is significantly increased and correlated with lesion degree and HPV infection status.

ObjectiveTo evaluate the metabolic stability of lucidin by incubating liver microsomes and liver S9 from 4 species， and to compare the species differences in metabolism of lucidin in vitro. MethodA qualitative and quantitative method of lucidin based on ultra-high performance liquid chromatography-high resolution mass spectrometry （UHPLC-HRMS） was established and verified. Lucidin was incubated with rat， mouse， beagle dog， human liver microsomes and liver S9 to investigate the metabolic stability parameters， metabolites， metabolic pathways. ResultHepatic clearance （CL_h） of lucidin was in order of mouse>rat>beagle dog>human in both phase Ⅰ and phase Ⅱ incubation system. Its metabolic stability was good in rat， beagle dog and human， while it showed metabolic instability and moderate metabolic stability in mouse microsomes and liver S9， respectively. A total of 5 metabolites were rapidly identified， including 3 oxidation metabolites of phase Ⅰ and 2 sulfation metabolites of phase Ⅱ. The production rate of metabolites was consistent with the results of metabolic stability. ConclusionThe established UHPLC-HRMS is simple and specific， which can be used for the study on the metabolic stability and metabolites of lucidin. Its metabolic stability and metabolite production rate in vitro are significantly different among species， the metabolic characteristics of rat and beagle dog are similar to human， which provides an important reference for subsequent research in vivo， safety evaluation and animal model selection of lucidin.

Objective:To explore the difference in the complexity of different treatment planning systems, multi-leaf collimator (MLC) types and treatment sites of volume-modulated arc therapy (VMAT), and propose a complexity score for plan quality control.Methods:Statistical analysis of 12 complexity metrics including Monaco and Eclipse, Agility, Millennium and High-definition MLC, nasopharyngeal, lung and cervical cancer was performed. Spearman correlation coefficient between complexity metrics was calculated. Principal component analysis was conducted to reduce the dimensionality of the original data set to the first two principal components and explain its physical meaning. Complexity score based on the principal components was calculated to establish warning and action thresholds for plan quality control. The correlation between complexity metrics and γ pass rate was analyzed.Results:Except cervical cancer aperture sub-regions metric, other metrics had significant differences between Monaco and Eclipse. Monaco MLC had a more regular field but higher MU, smaller leaf gap, and longer leaf travel distance. High-definition MLC with smaller leaf width significantly added MLC aperture-related metrics. The first two principal components explained over 80% of the total variance of the original dataset, complexity score was weighted average of first two principal components. The distribution of complexity score for different equipment and sites was different. The warning threshold was expressed as the average plus standard deviation, and the action threshold was expressed as the average plus 2 standard deviations. Complexity metrics and complexity scores had small correlation with γ pass rate, showing weak or irrelevant but statistically significant. Conclusions:Different planning systems, MLC types, and treatment site complexity metrics are significantly different. The complexity score is a useful tool for plan quality control.

Objective:To perform testing and clinical application of a volumetric-modulated arc therapy (VMAT) dosimetry verification system based on three-dimensional dose reconstruction of patient anatomical structures.Methods:ArcCheck array calibration was performed. Then, 200 MU was delivered with a 10 cm×10 cm field when the source to center of ArcCheck was 100 cm to calibrate the absolute dose and the dose was simultaneously measured by a FC65-G detector in the center of the ArcCheck. The absolute dose calibration value or the CT value of ArcCheck was adjusted to minimize the differences between the planning and measurement values of FC65-G, reconstructed value by 3DVH and reconstructed percent depth dose by 3DVH. 10 lung and 10 cervical cancer VMAT cases were selected and measured by ArcCheck and FC65-G under the delivery of a TrueBeam LINAC. The three-dimensional doses of all cases were reconstructed by 3DVH and compared with the planning and measurement values.Results:Different array calibration files of ArcCheck exerted different effect upon the two-dimensional dose measured by ArcCheck and three-dimensional dose reconstructed by 3DVH. The optimal reconstructed dose was obtained when self-calibration file was adopted and 249.96 cGy was regarded as the absolute dose calibration value. The deviations of the mean dose (D mean) and D 95% of the target were within ±4.2% and parameters of some organs at risk significantly differed compared with the reconstructed and planning dose for all cases. A negative mean point dose difference was obtained and the reconstructed dose was closer to the measured value. The γ-passing rate of the target for some cases was low, the proportion of regions irradiated by 50% prescription dose was slightly higher and the proportion of other organs was relatively high. Conclusion:The 3DVH model can be accurately established and tested with the acceptance test method in the present study, which can provide detailed information for dose verification.

Objective:To evaluate the volumetric modulated arc therapy (VMAT) dose verification of cervical cancer based on γ rule and dose volume histogram (DVH) and to perform correlation analysis between the evaluation results and the dose differences.Methods:Twenty cervical cancer VMAT plans were selected and performed on TrueBeam Linac. The delivered point and surface dose was measured by FC-65 G and ArcCheck and the results were compared to those calculated by Eclipse. The dose of patients was reconstructed by 3DVH. Then, differences between the reconstructed and plan value of D mean, D 95%, D 98% and D 2% of PTV, V 20Gy of left and right femoral head, V 40Gy of rectum, D 1cm 3 of cord, D 98%, D 2% and D 50% of the 50% prescription iso-dose volume (IDV), were evaluated and 3-dimensional (3D) γ was assessed for each organ. Lastly, Pearson’s correlation coefficient was used to analyze the relationship between point dose difference, 2D γ pass-rate (γ%), γ mean and 3D γ% of each organ and the dose difference. Results:Small differences were found between the point dose measured, reconstructed and the plan value. Differences between D mean of PTV, all dose parameters of IDV and plan values were all within 3% and V 40Gy of rectum showed the largest difference. As for the 3D γ%, the maximum pass rate was found for the left and right femoral head and the maximum variance for cord D 1cm 3. There was a moderate correlation between measured and reconstructed point dose deviation and dose difference of each organ, while no significant correlation was found for 2D γ%. Strong correlation was found between 3D γ% of target and D 50% of PTV/IDV and no correlation was found for other organs. Conclusion:The performance of both γ-and DVH-based evaluation can reveal dose error for dose verification, but both of them have some limitations and should be combined in clinical practice.

Objective:To analyze the competence assessment examinations of registered dietitians in China during 2017-2021 to inform the training of dietetic professionals.Methods:A systematic review was conducted about the composition and changing trends of examination participants during 2017-2021. Participants were divided into subgroups based on gender, age, education, professional background and affiliations and the qualification rate was compared across different subgroups.Results:The number of examination participants showed an increasing trend overall, with the majority being females and aged 26-35 years. The ratio of participants with bachelor's: master's: doctor's degree was about 15: 9: 1. The proportion of participants majoring in nutrition science decreased from 32.1% to 20.3%, while that of participants majoring in other medical and food sciences increased. Among participants from healthcare institutions, a decreasing proportion of participants were with a major in nutrition science, while this proportion among participants from companies were stable at 38.8% to 50.2%. The average qualification rate was 35.7%, showing no significant differences among different gender and age groups. But the qualification rate varied significantly across subgroups with different education level, professional background, and affiliations ( P < 0.05). Subgroups with more advanced degrees showed higher qualification rate and the best rate was observed in the subgroups with professional background in nutrition science and from nutrition-related institutions. Conclusion:The training of dietetic professionals in China should be improved, lifelong learning should be promoted in nutrition practitioners, and the sustainable development of dietitians should be impelled.

Objective:To evaluate the combined effect of an trajectory log field based(LBF)and two commercial dose reconstruction systems on volume-modulated arc therapy(VMAT)dose verification of lung cancer.Methods:An in-house program was developed to introduce errors in trajectory log of TrueBeam to the origin plan and recalculate the dose of the error plan in treatment planning system(TPS). A total of 18 lung cancer cases treated by two-arc VMAT were selected to perform on LINAC and measured by ArcCheck simultaneously. Then, the reconstructed doses were obtained by 3DVH. The mode of reconstruction was calculated by LFB and Compass. Five of the 18 cases were performed on LINAC two times in four hours and measured by ArcCheck to evaluate the stability of the TrueBeam performance. The 18 plans were recalculated and performed on LINAC with a solid water phantom with 5 cm build-up, 4 cm back scattering thickness and a FC65-G detector in the center. The measured dose by detector was compared with the reconstructed dose by three systems.Results:TheTruebeam performance was stable. For all of the 18 cases, the point dose measured by FC65-G and reconstructed by three systems had a deviation of less than 2% to the TPS calculated. For all of the organs reconstructed by LBF and most organs reconstructed by 3DVH and Compass, the γ pass rate between them and TPS all exceeded 90% under all criteria, as well as the ArcCheck measured results. For all the organ dose difference between reconstructed and TPS, LBF system had the smallest difference, followed by the Compass system except the lung, and the 3DVH had the highest difference.Conclusions:LBF, 3DVH and Compass can reflect the VMAT dose verification results of lung cancer from different perspectives. The combined application of three systems can demonstrate the verification results in an intuitive manner, which is beneficial for subsequent analysis.

Objective:To evaluate the multi-leaf collimator (MLC) performance of TrueBeam accelerator using trajectory log files.Methods:All tests were performed 5 times under different gantry-collimator angle combination. The 1 mm picket fences were constructed by static or dynamic MLC. The control ability for small-field accuracy of accelerator was evaluated. Repeatability was assessed by MLC repeat motion. The movement performance of difference velocities along one direction and the opposite direction were evaluated via a 1 cm picket fences which slipped from -7 cm to 7 cm with a uniform velocity and stopped or immediately back at 7 cm. The MLC performance in a complex program was evaluated by a cross movement test.Results:Both the static and the dynamic picket fences yielded high accuracy. The deviation spectrums of MLC in different gantry angle were consistent, however, an absolute difference of 0.001 1 mm was found. For uniform velocity movement tests with 0°gantry, the RMSE of MLC was increased from 0.015 0 mm to 0.059 8 mm when the speed was accelerated from 5 mm/s to 25 mm/s. Similar results were obtained in non-zero gantry angle. The "overspeed" effect caused by the direction change movement of MLC was less obvious than that caused by speed changed from zero to a uniform velocity movement state. There was no significant change in speed before and after the MLC crossing. The MLC speed fluctuated around the set value, which was independent of the gantry angle.Conclusion:A method for evaluating the performance of MLC using trajectory log files is established, which can evaluate the MLC performance of TrueBeam accelerator and be used for MLC rapid quality control in clinical practice.