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.

We retrospectively analyzed 8 patients who had been on hemodialysis for over 30 years from two dialysis centers in Dalian, China. A literature review was conducted by searching PubMed, CNKI, Wanfang databases,and Chinese Medical Journal Network for cases of patients on hemodialysis for over 30 years. The 8 patients had good baseline health, with chronic glomerulonephritis as the primary renal disease and no comorbidities before initiating dialysis. They started hemodialysis between 21 and 38 years of age, predominantly using arteriovenous fistulas for vascular access. Dialysis was regular and adequate (KT/V 1.23-1.88). Key laboratory parameters, including hemoglobin (88-118 g/L), albumin (27.7-39.7 g/L), calcium (1.88-2.55 mmol/L), and phosphate (0.76-1.99 mmol/L), were generally within target ranges. Body mass index ranged from 15.20 to 22.96 kg/m2. This literature review of the study included 12 case reports and 4 orginal articles. Factors influencing long-term survival included baseline health status, primary renal disease, absence of comorbidities before dialysis initiation, age at dialysis initiation, type of vascular access, dialysis adequacy, complication management, and medical support. Standardized management and timely correction of complications can significantly improve prognosis and enhance long-term survival in hemodialysis patients.

Renal cell carcinoma（RCC）has a relatively high incidence among genitourinary malignancies and therefore occupies a pivotal position in the diagnosis and treatment of urological tumors. Its staging，grading，and corresponding therapeutic strategies have been relatively well established. However，in clinical practice，we have observed that a subset of patients with RCC，preoperatively diagnosed as stage T1 based on imaging，are found on postoperative pathology after partial nephrectomy to have tumor extension into the renal sinus，resulting in pathological upstaging（cT 1/pT 3a）. Multiple studies have demonstrated that the overall prognosis of cT 1/pT 3a patients undergoing partial nephrectomy is inferior to that of cT 1/pT 1 patients，but shows no significant difference compared with cT 1/pT 3a patients treated with radical nephrectomy. Moreover，partial nephrectomy offers clear advantages over radical nephrectomy in terms of intraoperative blood loss and preservation of renal function parameters such as estimated glomerular filtration rate（eGFR）and serum creatinine，which translate into improved quality of life. In addition，this paper introduces predictive methods for pathological upstaging in partial RCC，including novel imaging-based approaches such as the contour irregular degree（CID）on computed tomography（CT），histopathological predictors such as Fuhrman grading，and the preliminary application of machine learning in enhancing diagnostic accuracy.

We retrospectively analyzed 8 patients who had been on hemodialysis for over 30 years from two dialysis centers in Dalian, China. A literature review was conducted by searching PubMed, CNKI, Wanfang databases,and Chinese Medical Journal Network for cases of patients on hemodialysis for over 30 years. The 8 patients had good baseline health, with chronic glomerulonephritis as the primary renal disease and no comorbidities before initiating dialysis. They started hemodialysis between 21 and 38 years of age, predominantly using arteriovenous fistulas for vascular access. Dialysis was regular and adequate (KT/V 1.23-1.88). Key laboratory parameters, including hemoglobin (88-118 g/L), albumin (27.7-39.7 g/L), calcium (1.88-2.55 mmol/L), and phosphate (0.76-1.99 mmol/L), were generally within target ranges. Body mass index ranged from 15.20 to 22.96 kg/m2. This literature review of the study included 12 case reports and 4 orginal articles. Factors influencing long-term survival included baseline health status, primary renal disease, absence of comorbidities before dialysis initiation, age at dialysis initiation, type of vascular access, dialysis adequacy, complication management, and medical support. Standardized management and timely correction of complications can significantly improve prognosis and enhance long-term survival in hemodialysis patients.

Renal cell carcinoma（RCC）has a relatively high incidence among genitourinary malignancies and therefore occupies a pivotal position in the diagnosis and treatment of urological tumors. Its staging，grading，and corresponding therapeutic strategies have been relatively well established. However，in clinical practice，we have observed that a subset of patients with RCC，preoperatively diagnosed as stage T1 based on imaging，are found on postoperative pathology after partial nephrectomy to have tumor extension into the renal sinus，resulting in pathological upstaging（cT 1/pT 3a）. Multiple studies have demonstrated that the overall prognosis of cT 1/pT 3a patients undergoing partial nephrectomy is inferior to that of cT 1/pT 1 patients，but shows no significant difference compared with cT 1/pT 3a patients treated with radical nephrectomy. Moreover，partial nephrectomy offers clear advantages over radical nephrectomy in terms of intraoperative blood loss and preservation of renal function parameters such as estimated glomerular filtration rate（eGFR）and serum creatinine，which translate into improved quality of life. In addition，this paper introduces predictive methods for pathological upstaging in partial RCC，including novel imaging-based approaches such as the contour irregular degree（CID）on computed tomography（CT），histopathological predictors such as Fuhrman grading，and the preliminary application of machine learning in enhancing diagnostic accuracy.

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 investigate the efficacy of rigid ureteroscopic laser lithotripsy combined with N-trap(RULL+N-trap),which is scoop-shaped,in the treatment of ureteral stones with a maximum diameter ≥1.5 cm.Methods:This retrospective cohort study included patients diagnosed with ureteral calculi who underwent rigid ureteroscopic lithotripsy(RULL)combined with N-Trap stone entrapment system at the Department of Urology,Peking University Third Hospital,by the same surgical team between June 2021 and September 2024.A total of 364 patients were initially enrolled.After excluding 21 patients due to missing critical outcome variables,two distinct cohorts were established:38 patients with ureteral stones measuring ≥1.5 cm in maximum diameter,and 305 patients with stones＜1.5 cm in maximum diameter.To minimize selection bias and control for confounding variables,propensity score matching(PSM)was employed.This resulted in two well-balanced groups:31 patients with stones 1.5 cm in maximum diameter and 31 patients with stones＜1.5 cm in maximum diameter,matched on baseline demographic and clinical characteristics.The primary outcomes assessed between the two groups included stone clearance.Secondary outcomes included changes in renal function indicators,specifically serum creatinine(SCr)and estimated glomerular filtration rate(GFR),and other factors like postopera-tive hospital stay and operative time.Results:In the matched cohort,the patients with stones ≥1.5 cm in maximum diameter had significantly longer operative time compared with those with smaller stones:(85.8±28.8)min vs.(62.4±24.6)min(P＜0.05).Postoperative length of hospital stay showed no significant difference:(2.26±1.79)d vs.(2.03±0.80)d(P＞0.05).The stone clearance on postoperative day one was 90.3％in the study group vs.100.0％in the control group(P＞0.05).One month postoperatively,the stone clearance was 93.5％vs.100.0％,respectively(P＞0.05).Changes in SCr were(-6.58±16.10)μmol/L vs.(-13.70±12.50)μmol/L,and changes in GFR were(5.92±14.90)mL/(min·1.73 m2)vs.(7.47±11.20)m L/(min·1.73 m2),with no statistically significant differences observed between the two groups for either renal function marker(P＞0.05).Conclusion:Ureteroscopic lithotripsy combined with N-trap is an optional method for treating ureteral stones with a maximum diameter ≥1.5 cm.The overall therapeutic efficacy is comparable,with the added benefit of significantly reducing the economic burden on patients.

Objective:To investigate the efficacy of rigid ureteroscopic laser lithotripsy combined with N-trap(RULL+N-trap),which is scoop-shaped,in the treatment of ureteral stones with a maximum diameter ≥1.5 cm.Methods:This retrospective cohort study included patients diagnosed with ureteral calculi who underwent rigid ureteroscopic lithotripsy(RULL)combined with N-Trap stone entrapment system at the Department of Urology,Peking University Third Hospital,by the same surgical team between June 2021 and September 2024.A total of 364 patients were initially enrolled.After excluding 21 patients due to missing critical outcome variables,two distinct cohorts were established:38 patients with ureteral stones measuring ≥1.5 cm in maximum diameter,and 305 patients with stones＜1.5 cm in maximum diameter.To minimize selection bias and control for confounding variables,propensity score matching(PSM)was employed.This resulted in two well-balanced groups:31 patients with stones 1.5 cm in maximum diameter and 31 patients with stones＜1.5 cm in maximum diameter,matched on baseline demographic and clinical characteristics.The primary outcomes assessed between the two groups included stone clearance.Secondary outcomes included changes in renal function indicators,specifically serum creatinine(SCr)and estimated glomerular filtration rate(GFR),and other factors like postopera-tive hospital stay and operative time.Results:In the matched cohort,the patients with stones ≥1.5 cm in maximum diameter had significantly longer operative time compared with those with smaller stones:(85.8±28.8)min vs.(62.4±24.6)min(P＜0.05).Postoperative length of hospital stay showed no significant difference:(2.26±1.79)d vs.(2.03±0.80)d(P＞0.05).The stone clearance on postoperative day one was 90.3％in the study group vs.100.0％in the control group(P＞0.05).One month postoperatively,the stone clearance was 93.5％vs.100.0％,respectively(P＞0.05).Changes in SCr were(-6.58±16.10)μmol/L vs.(-13.70±12.50)μmol/L,and changes in GFR were(5.92±14.90)mL/(min·1.73 m2)vs.(7.47±11.20)m L/(min·1.73 m2),with no statistically significant differences observed between the two groups for either renal function marker(P＞0.05).Conclusion:Ureteroscopic lithotripsy combined with N-trap is an optional method for treating ureteral stones with a maximum diameter ≥1.5 cm.The overall therapeutic efficacy is comparable,with the added benefit of significantly reducing the economic burden on patients.

Bladder metastasis of pancreatic cancer is rare in the clinic.The male patient was diagnosed with pancreatic cancer and underwent laparoscopic pancreaticoduodenectomy. An abdominopelvic CT examination was performed 18 months after the operation and found a new bladder mass. Transurethral resection of bladder tumor was performed, and pathological examination showed that the mass was consistent with metastasis of pancreatic poorly differentiated adenocarcinoma. The patient received chemotherapy after the operation, and there was no tumor recurrence or new metastasis on PET-CT imaging after 8 months of follow-up. This case suggested the possibility of metastasis if a bladder mass was present after the surgery of pancreatic cancer.

Objective:To explore the genetic etiology of a child with Cowden syndrome 1 (CS1).Methods:A child who had visited the Ningbo Women and Children's Hospital on August 26, 2022 was selected as the study subject. Clinical information of the child was collected. Genomic DNA was extracted from peripheral blood samples of the child and his family members and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing.Results:The child, a 13-year-old boy, had manifested with severe mental retardation, hyperactivity, autistic behavior, sparse and prominent teeth, macrocephaly, and skin freckles on the penis. His mother had presented with multiple papules, hamartomatous polyps, thyroid adenoma and macrocephaly. WES results revealed that the child has harbored a nonsense c. 781C>T (p.Q261*) variant of the PTEN gene, which was inherited from his mother. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.781C>T variant was classified as likely pathogenic (PVS1+ PM2_Supporting). Conclusion:The c. 781C>T variant of the PTEN gene probably underlay the pathogenesis in the child and his mother. Above finding has facilitated genetic counseling for this family.