Objective:To reveal the coupling mechanism of beam temporal profile and tissue oxygen content on radical kinetics, further explain the potential biological basis of the FLASH effect, and provide a reference for beam optimization and treatment planning design of FLASH radiotherapy (FLASH-RT).Methods:TOPAS-nBio v3.0 was used to simulate the physical and chemical processes of electron beams in water, and a full-scale kinetic model was established covering the generation, diffusion, reaction, and quenching of free radicals such as hydroxyl radical (·OH) and hydrated electrons (e aq-). Under different beam temporal profiles (single pulse, multi-pulses, continuous wave irradiation) and different oxygen concentration conditions, the evolution dynamics of free radicals were systematically simulated. At the same time, the data on e aq- content were obtained by experimental measurement of laser absorption spectroscopy to verify the accuracy of the model prediction. Results:The changing trend of e aq- concentration measured in the experiment was highly consistent with the simulation result, verifying the reliability of the constructed model. The beam time structure had a significant impact on the peak value and duration of free radical concentration. The single-pulse structure can cause the free radicals to rapidly increase and then quickly quench in a short time, while the continuous or long-pulse structure can cause the radical concentration to remain at a high level for a long time. The evolution of ·OH was not sensitive to the oxygen environment, while e aq- are greatly affected by the oxygen environment. The scavenging efficiency of free radicals in a hypoxic environment was significantly decreased, leading to an enhanced accumulation of oxidative damage to biological macromolecules. The lifespan of e aq- in an oxygen-rich environment decreased rapidly. Conclusions:Radical kinetics are regulated by both the beam temporal profile and oxygen content. FLASH-RT can utilize single-pulse or multi-pulses intervals to form periodic windows, reducing normal tissue damage by efficiently scavenging free radicals through antioxidants, while free radicals in tumor tissues continuously accumulate and amplify damage, thus generating a selective protective effect.

Objective To propose an effective objective acoustic voice assessment method for detecting vocal fold nodules in children.Methods Continuous vowel sounds/a/from 48 children with vocal fold nodules and 40 healthy chil-dren were analyzed using multi-band cepstral analysis.Thirteen Mel-frequency cepstral coefficients(MFCC),five cepstral peak values,and six cepstral distances were extracted as subband features.An independent sample t-test was conducted to compare the acoustic feature parameters between the two groups.Features with statistically significant differences were fur-ther analyzed using the receiver operating characteristic(ROC)curve to identify the optimal acoustic features with the high-est discriminative power for detecting vocal fold nodule disorders.Results The MFCC2,MFCC3,MFCC5,MFCC11,MFCC12,DQP,EP1,and EP2 feature values were significantly higher in the vocal fold nodule group compared to the nor-mal children group(P＜0.05,P＜0.001),while MFCC1,MFCC6,MFCC8,MFCC13,and EEP were significantly lower(P＜0.05).ROC curve analysis of these features showed that the combined ROC curve area under the curve(AUC)for MFCC1,MFCC2,MFCC3,MFCC5,MFCC6,MFCC8,MFCC11,MFCC12,MFCC13,DQP,EP1,EP2,and EEP was 0.98.The individual AUCs for MFCC1,MFCC2,MFCC3,MFCC5,MFCC6,MFCC8,MFCC11,MFCC12,DQP,and EP2 were all greater than 0.7,indicating a certain level of accuracy.Among these,MFCC2 and MFCC3 had AUCs of 0.85 and 0.87,respectively,indicating that these features have high diagnostic value for vocal fold nodule-related voice seg-ments in children.Conclusion The specific combination of acoustic parameters derived from multiband cepstral features of sustained vowels,including Mel-frequency cepstral coefficients(MFCC1,MFCC2,MFCC3,MFCC5,MFCC6,MFCC8,MFCC11,MFCC12,MFCC13)and cepstral peak values(DQP,EP1,EP2,EEP),can enhance the accuracy of detecting vocal fold nodule-related voice disorders in children.Particularly,MFCC2 and MFCC3 demonstrate high sensitivity and specificity,enabling more accurate identification of vocal fold nodule-related voice disorders in children.

Objective To analyze the risk factors for elevated serum amylase level in patients with abdominal aortic aneurysm(AAA)after receiving endovascular aortic repair(EVAR).Methods The clinical data of 162 patients with AAA,who received EVAR at the First Medical Center of Chinese PLA General Hospital of China from June 2020 to June 2021,were retrospectively analyzed.According to postoperative blood amylase level,the patients were divided into elevated amylase group(＞150 U/L)and non-elevated amylase group(≤150 U/L).Univariate analysis and multivariate logistic regression model were used to screen out the independent risk factors for elevated amylase.Results Of the 162 patients with AAA after receiving EVAR,54(33.3％,54/162)developed elevated blood amylase.Multivariate logistic regression analysis showed that after adjusting the age,systolic blood pressure,leukocyte,platelet,thrombin time,APTT,fibrinogen,D-dimer,creatinine,alanine aminotransferase,aspartate aminotransferase,operation time and amount of intraoperative blood loss,the preoperative urea level was well correlated with the postoperative blood amylase elevation(OR=1.69,95％CI=1.085-2.650).Conclusion Preoperative urea level is a risk factor for the postoperative blood amylase elevation in patients with AAA after receiving EVAR.

Objective To propose an effective objective acoustic voice assessment method for detecting vocal fold nodules in children.Methods Continuous vowel sounds/a/from 48 children with vocal fold nodules and 40 healthy chil-dren were analyzed using multi-band cepstral analysis.Thirteen Mel-frequency cepstral coefficients(MFCC),five cepstral peak values,and six cepstral distances were extracted as subband features.An independent sample t-test was conducted to compare the acoustic feature parameters between the two groups.Features with statistically significant differences were fur-ther analyzed using the receiver operating characteristic(ROC)curve to identify the optimal acoustic features with the high-est discriminative power for detecting vocal fold nodule disorders.Results The MFCC2,MFCC3,MFCC5,MFCC11,MFCC12,DQP,EP1,and EP2 feature values were significantly higher in the vocal fold nodule group compared to the nor-mal children group(P＜0.05,P＜0.001),while MFCC1,MFCC6,MFCC8,MFCC13,and EEP were significantly lower(P＜0.05).ROC curve analysis of these features showed that the combined ROC curve area under the curve(AUC)for MFCC1,MFCC2,MFCC3,MFCC5,MFCC6,MFCC8,MFCC11,MFCC12,MFCC13,DQP,EP1,EP2,and EEP was 0.98.The individual AUCs for MFCC1,MFCC2,MFCC3,MFCC5,MFCC6,MFCC8,MFCC11,MFCC12,DQP,and EP2 were all greater than 0.7,indicating a certain level of accuracy.Among these,MFCC2 and MFCC3 had AUCs of 0.85 and 0.87,respectively,indicating that these features have high diagnostic value for vocal fold nodule-related voice seg-ments in children.Conclusion The specific combination of acoustic parameters derived from multiband cepstral features of sustained vowels,including Mel-frequency cepstral coefficients(MFCC1,MFCC2,MFCC3,MFCC5,MFCC6,MFCC8,MFCC11,MFCC12,MFCC13)and cepstral peak values(DQP,EP1,EP2,EEP),can enhance the accuracy of detecting vocal fold nodule-related voice disorders in children.Particularly,MFCC2 and MFCC3 demonstrate high sensitivity and specificity,enabling more accurate identification of vocal fold nodule-related voice disorders in children.

Objective:To reveal the coupling mechanism of beam temporal profile and tissue oxygen content on radical kinetics, further explain the potential biological basis of the FLASH effect, and provide a reference for beam optimization and treatment planning design of FLASH radiotherapy (FLASH-RT).Methods:TOPAS-nBio v3.0 was used to simulate the physical and chemical processes of electron beams in water, and a full-scale kinetic model was established covering the generation, diffusion, reaction, and quenching of free radicals such as hydroxyl radical (·OH) and hydrated electrons (e aq-). Under different beam temporal profiles (single pulse, multi-pulses, continuous wave irradiation) and different oxygen concentration conditions, the evolution dynamics of free radicals were systematically simulated. At the same time, the data on e aq- content were obtained by experimental measurement of laser absorption spectroscopy to verify the accuracy of the model prediction. Results:The changing trend of e aq- concentration measured in the experiment was highly consistent with the simulation result, verifying the reliability of the constructed model. The beam time structure had a significant impact on the peak value and duration of free radical concentration. The single-pulse structure can cause the free radicals to rapidly increase and then quickly quench in a short time, while the continuous or long-pulse structure can cause the radical concentration to remain at a high level for a long time. The evolution of ·OH was not sensitive to the oxygen environment, while e aq- are greatly affected by the oxygen environment. The scavenging efficiency of free radicals in a hypoxic environment was significantly decreased, leading to an enhanced accumulation of oxidative damage to biological macromolecules. The lifespan of e aq- in an oxygen-rich environment decreased rapidly. Conclusions:Radical kinetics are regulated by both the beam temporal profile and oxygen content. FLASH-RT can utilize single-pulse or multi-pulses intervals to form periodic windows, reducing normal tissue damage by efficiently scavenging free radicals through antioxidants, while free radicals in tumor tissues continuously accumulate and amplify damage, thus generating a selective protective effect.

Objective:To evaluate the application effect of a new type of laparoscopic multi-degree-of-freedom surgical instrument in the training of basic surgical skills and analyze the learning curve.Methods:The teaching records of the trainees who received training in the training base of laparoscopic surgeons in Chinese People′s Liberation Army General Hospital from January to October, 2023 were collected. The 50 trainees were randomly divided into conventional instrumentation group and new instrumentation group with 25 trainees in each group according to the random number table method before the training. According to the research design, five modules such as "accurate bean clamping, plum blossom pile bean clamping, ferrule positioning, threading with both hands, sewing and knotting" were trained. After the training, they were assessed and the completion time of each module was recorded. The comparison of the changes of the completion time of the two groups of students before and after training was statistically analyzed by differences-in-differences(DID) method, and the fitting analysis of learning curve was analyzed by cumulative summation method .Results:Before the training, there was no statistically significant difference in the time required to complete five modules between the two groups of trainees (all P>0.05). After the training, the time to complete the five modules in both groups was reduced compared to before the training (accurate bean clamping: (63.7±9.3) seconds vs. (85.4±18.2) seconds, t=2.38, P=0.035; plum blossom pile bean clamping: (45.2±6.8) seconds vs. (103.1±57.2) seconds, t=8.77, P=0.047; ring positioning: (78.5±19.1) seconds vs. (126.2±26.3) seconds, t=6.96, P=0.019; threading with both hands: (63.3±21.2) seconds vs. (105.8±27.9) seconds, t=3.43, P=0.015; sewing and knotting: (160.2±79.5) seconds vs. (228.9±96.6) seconds, t=4.58, P=0.008).The average time required to complete the five modules was shorter in the new instrument group compared to the conventional instrument group (DID for accurate bean clamping=37.66, t=2.43, P=0.007; DID for plum blossom pile bean clamping=58.42, t=3.03, P=0.013; DID for ferrule positioning=28.33, t=2.83, P=0.031; DID for threading with both hands=48.89, t=2.10, P=0.042; DID for sewing and knotting=54.78, t=3.57, P=0.012). In the learning curves for the plum blossom pile bean clamping, ferrule positioning, and sewing and knotting modules, the new instrument group required fewer class hours to reach proficiency compared to the conventional instrument group (plum blossom pile bean clamping: 3 class hours vs. 4 class hours; ferrule positioning: 4 class hours vs. 5 class hours; sewing and knotting: 3 class hours vs. 5 class hours). In the accurate bean clamping and threading with both hands modules, both the conventional and new instrument groups crossed the learning curve at the 5 th class hour, but there was a statistically significant difference in the slopes of the curves between the two groups (accurate bean clamping: t=-2.85, P=0.004; threading with both hands: t=-2.66, P=0.008). Conclusion:The new type of laparoscopic multi-degree-of-freedom surgical instruments can improve the learning effect and shorten the learning curve in laparoscopic training teaching, which shows good application effect and has the possibility of clinical trial.

Objective:To evaluate the application effect of a new type of laparoscopic multi-degree-of-freedom surgical instrument in the training of basic surgical skills and analyze the learning curve.Methods:The teaching records of the trainees who received training in the training base of laparoscopic surgeons in Chinese People′s Liberation Army General Hospital from January to October, 2023 were collected. The 50 trainees were randomly divided into conventional instrumentation group and new instrumentation group with 25 trainees in each group according to the random number table method before the training. According to the research design, five modules such as "accurate bean clamping, plum blossom pile bean clamping, ferrule positioning, threading with both hands, sewing and knotting" were trained. After the training, they were assessed and the completion time of each module was recorded. The comparison of the changes of the completion time of the two groups of students before and after training was statistically analyzed by differences-in-differences(DID) method, and the fitting analysis of learning curve was analyzed by cumulative summation method .Results:Before the training, there was no statistically significant difference in the time required to complete five modules between the two groups of trainees (all P>0.05). After the training, the time to complete the five modules in both groups was reduced compared to before the training (accurate bean clamping: (63.7±9.3) seconds vs. (85.4±18.2) seconds, t=2.38, P=0.035; plum blossom pile bean clamping: (45.2±6.8) seconds vs. (103.1±57.2) seconds, t=8.77, P=0.047; ring positioning: (78.5±19.1) seconds vs. (126.2±26.3) seconds, t=6.96, P=0.019; threading with both hands: (63.3±21.2) seconds vs. (105.8±27.9) seconds, t=3.43, P=0.015; sewing and knotting: (160.2±79.5) seconds vs. (228.9±96.6) seconds, t=4.58, P=0.008).The average time required to complete the five modules was shorter in the new instrument group compared to the conventional instrument group (DID for accurate bean clamping=37.66, t=2.43, P=0.007; DID for plum blossom pile bean clamping=58.42, t=3.03, P=0.013; DID for ferrule positioning=28.33, t=2.83, P=0.031; DID for threading with both hands=48.89, t=2.10, P=0.042; DID for sewing and knotting=54.78, t=3.57, P=0.012). In the learning curves for the plum blossom pile bean clamping, ferrule positioning, and sewing and knotting modules, the new instrument group required fewer class hours to reach proficiency compared to the conventional instrument group (plum blossom pile bean clamping: 3 class hours vs. 4 class hours; ferrule positioning: 4 class hours vs. 5 class hours; sewing and knotting: 3 class hours vs. 5 class hours). In the accurate bean clamping and threading with both hands modules, both the conventional and new instrument groups crossed the learning curve at the 5 th class hour, but there was a statistically significant difference in the slopes of the curves between the two groups (accurate bean clamping: t=-2.85, P=0.004; threading with both hands: t=-2.66, P=0.008). Conclusion:The new type of laparoscopic multi-degree-of-freedom surgical instruments can improve the learning effect and shorten the learning curve in laparoscopic training teaching, which shows good application effect and has the possibility of clinical trial.

ObjectiveTo investigate the expression of TM6SF2 in hepatocellular carcinoma (HCC) tissue and its biological functions by data mining in tumor databases. MethodsThe GEPIA database was applied to measure the change in the mRNA expression level of TM6SF2 in HCC tissue, and OncoLnc was used to analyze the association of TM6SF2 expression with the survival time of HCC patients. The cBioPortal and LinkedOmics databases were used to analyze the genes associated with the expression of TM6SF2 in HCC tissue, and the DAVID6.8 and STRING databases were used to perform a bioinformatics analysis of TM6SF2 and the genes associated with its expression. The t-test was used to investigate the difference in the mRNA expression of TM6SF2 between HCC tissue and adjacent tissue. The Spearman correlation coefficient was used to analyze the correlation of gene expression. The Kaplan-Meier method was used to calculate survival percentage, and the log-rank test was used to analyze the difference in survival percentage. ResultsCompared with the normal liver tissue, the HCC tissue had low mRNA expression of TM6SF2 (｜log2FC｜cut-off = 0.5, P＜0.01). Compared with those with high expression of TM6SF2, the patients with low expression had a significant reduction in overall survival time (χ2=9.897，P＜0.01). Data analysis showed that a total of 49 genes were associated with the expression of TM6SF2 in HCC tissue, and the gene ontology analysis showed that these genes were enriched in the biological processes and functions including fatty acid synthesis, fatty acid ligase activation, and thrombin regulation (P＜0.05). The Kyoto Encyclopedia of Genes and Genome pathway analysis showed that these genes were mainly involved in the signaling pathways of alanine metabolism, peroxisome proliferator-activated receptor signaling pathway, and bile secretion (P＜0.05). The protein-protein interaction network analysis showed that the genes of SERPINC1, NR1I2, SERPINA10, and SLC10A1 had marked or potential interaction with TM6SF2 (P＜0.01). ConclusionTumor data mining can quickly obtain the information on the expression of TM6SF2 in HCC tissue and provide a bioinformatics basis for exploring the role of TM6SF2 in the development and progression of HCC.

Objective: To introduce the method of transoral coblation-assisted endoscopic minimally invasive surgery for superficial tongue base tumour. Methods: A total of 15 patients treated with transoral coblation-assisted endoscopic minimally invasive surgery from Mar. 2006 to Aug. 2016 were retrospectively reviewed. There were 9 patients with malignant tumors, 6 patients with benign neoplasms. Adjuvant postoperative radiation therapy was applied in three cases of squamous cell carcinoma, neck was performed in four cases of cancer. One case of non-Hodgkin lymphoma received postoperative chemotherapy. Results: One case with ectopic thyroid gland was treated by subtotal resection and one case with squamous cell carcinoma changed into open surgery because of major lingual artery bleeding. The En bloc resection under edoscope was achieved in 92.86%(13/14)of patients. Fifteen cases of neoplasms were followed-up for 8-50 months(median 20 months), one patient with Cowden syndrome was lost to follow-up because of appendical carcinoid combined pulmonary metastasis, one patient with non-Hodgkin lymphoma died of recurrence in other head neck areas 2 years after chemotherapy. Conclusion Transoral coblation-assisted endoscopic surgery can successfully treat for the patients with superficial tongue base tumours.