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.

Acute Kidney Injury (AKI) is a common and severe complication after cardiac surgery. The pathogenesis of cardiac surgery-associated AKI (CSA-AKI) is complex, and it is associated with increased patient mortality and poor renal prognosis. To identify high-risk patients as early as possible, numerous clinical studies have explored perioperative risk factors and developed a variety of biomarkers with good diagnostic capabilities. Currently, multiple prediction models for AKI after cardiac surgery have been developed internationally; however, there is no effective treatment for CSA-AKI. Therefore, implementing reasonable and comprehensive preventive strategies is crucial. In addition, the clinical application of some interventions is controversial, which means more research and exploration are needed to make more informed decisions regarding the prevention and treatment of CSA-AKI.

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.

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.

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.

Acute kidney injury (AKI) usually requires renal replacement therapy (RRT). Common RRT modes include peritoneal dialysis, continuous renal replacement therapy, intermittent hemodialysis and continuous low-efficiency hemodialysis. In clinical practice, there is still controversy over how to select the appropriate RRT mode for AKI patients and when initiating RRT is more beneficial for AKI patients. This article summarizes previous studies on the impact of RRT mode and initiation timing on the prognosis of AKI patients, with the aim of providing assistance for clinical decision-making.

Acute kidney injury (AKI) usually requires renal replacement therapy (RRT). Common RRT modes include peritoneal dialysis, continuous renal replacement therapy, intermittent hemodialysis and continuous low-efficiency hemodialysis. In clinical practice, there is still controversy over how to select the appropriate RRT mode for AKI patients and when initiating RRT is more beneficial for AKI patients. This article summarizes previous studies on the impact of RRT mode and initiation timing on the prognosis of AKI patients, with the aim of providing assistance for clinical decision-making.

Acute Kidney Injury (AKI) is a common and severe complication after cardiac surgery. The pathogenesis of cardiac surgery-associated AKI (CSA-AKI) is complex, and it is associated with increased patient mortality and poor renal prognosis. To identify high-risk patients as early as possible, numerous clinical studies have explored perioperative risk factors and developed a variety of biomarkers with good diagnostic capabilities. Currently, multiple prediction models for AKI after cardiac surgery have been developed internationally; however, there is no effective treatment for CSA-AKI. Therefore, implementing reasonable and comprehensive preventive strategies is crucial. In addition, the clinical application of some interventions is controversial, which means more research and exploration are needed to make more informed decisions regarding the prevention and treatment of CSA-AKI.

ObjectiveTo investigate the change and potential role of Mindin protein in the treatment of chronic hepatitis B （CHB） with PEG-IFNα-2b. MethodsA total of 29 CHB patients who received the treatment with PEG-IFNα-2b in The Second Affiliated Hospital of Xi’an Jiaotong University from January 2018 to December 2019 were enrolled， and according to their clinical outcome， they were divided into cured group with 17 patients and uncured group with 12 patients. Peripheral blood samples were collected from both groups at baseline， 12 weeks， and 24 weeks to measure blood routine indices， liver function parameters， hepatitis B markers， and Mindin protein. HBsAg， alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， and Mindin protein at different time points were compared between the two groups. The independent-samples t test was used for comparison of normally distributed continuous data between two groups， and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups； a Spearman correlation analysis was used to investigate correlation； a multiple linear regression analysis was used to investigate the influence of HBsAg and ALT on the content of Mindin protein. ResultsThe analysis of baseline data showed that there were significant differences in the levels of HBsAg， HBeAb， albumin， and albumin/globulin ratio between the cured group and the uncured group （all P<0.05）. The cured group tended to have a gradual increase in the level of Mindin， and the level of Mindin at 24 weeks was significantly higher than that at baseline （P<0.05）. The cured group had a significantly higher level of Mindin protein than the uncured group at 24 weeks （P=0.019）. The cured group had a significantly lower level of HBsAg than the uncured group （P<0.05）， with a significant change from baseline to each time point within the cured group （P<0.05）. In addition， the levels of ALT and AST in the cured group tended to first increase and then decrease， and the expression levels at 12 weeks were significantly higher than those at baseline （P<0.05）. At 12 weeks， there was a strong linear correlation between Mindin protein levels and ALT in the untreated group （r=0.760 8， P<0.05）， and further multiple linear regression analysis also demonstrated a linear relationship between the two （b=1.571， P=0.019）. ConclusionThere is a significant difference in the level of Mindin protein between the cured group and the non-cured group after 24 weeks of PEG-IFNα-2b antiviral treatment， and therefore， detecting the dynamic changes of Mindin protein can better predict the treatment outcome of CHB， which provides a reference for clinical practice.

BACKGROUND:Mechanical stimulation has been confirmed to promote osteogenic differentiation of bone marrow stromal stem cells,but the mechanism is unknown.Primary cilia are important mechanoreceptors and regulate various signaling pathways such as TGF-β1/BMP-2/SMAD.They are likely to be important targets for mechanical regulation of bone marrow stromal stem cells. OBJECTIVE:To investigate the effect and mechanism of fluid shear stress on osteogenic differentiation of bone marrow stromal stem cells. METHODS:Rat bone marrow stromal stem cells were divided into control group,mechanical stimulation group(fluid shear mechanics intervention by shaking table),mechanical stimulation + IFT88 silencing group(mechanical stimulation + silencing IFT88 expression with siRNA).After 24 hours of intervention,qRT-PCR was utilized to determine the expression of transforming growth factor β1 and bone morphogenetic protein 2.Western blot assay was used to detect the expression of phosphorylated SMAD2/3 protein.Immunofluorescent staining of primary cilia was conducted and morphology was analyzed. RESULTS AND CONCLUSION:Shear stress stimulation could promote the transcriptional activity of transforming growth factor β1 and bone morphogenetic protein 2 genes,and increase the expression of phosphorylated SMAD2/3 protein.After siRNA interfered with primary cilia,this mechanical response effect was significantly reduced.There was a Spearman correlation between the change ratio of the primary cilium area of bone marrow stromal stem cells and the increased ratio of transforming growth factor β1 and bone morphogenetic protein 2 gene transcription.These findings indicate that primary cilia/intraflagellar transport mediates the activation of fluid shear stress-responsive transforming growth factor β1/bone morphogenetic protein 2/SMAD signaling pathway and promotes osteogenic differentiation of bone marrow stromal stem cells.