ObjectiveA mouse model of vaccinia virus Tiantan strain (VTT)-induced encephalopathy was developed using AG6 mice. MethodsVTT was amplified by infecting Vero cells at a multiplicity of infection (MOI) of 0.01, followed by concentration and titration. After 72 h of incubation, virus-containing cells were collected and subjected to concentration. The concentrated viral suspension was serially diluted (10-fold dilutions) and added to 6-well plates containing confluent Vero cell monolayers for plaque assay. The number of plaques formed in each well was counted, and the virus titer was calculated based on the dilution factor. Fourteen 5-6-week-old AG6 mice (half male and half female, housed separately by sex) were randomly divided into a control group (n=3, PBS), a low-dose group (n=6, 1×10⁵ PFU), and a high-dose group (n=5, 5×10⁵ PFU). The mice were anesthetized by isoflurane inhalation and then infected via intranasal instillation. The mental state of the mice in each group was observed daily, and the body weight and mortality were recorded. On day 13 post-infection, 2% Evans Blue (4 mL/kg body weight) was administered via tail vein injection to assess blood-brain barrier (BBB) disruption. Subsequently, brain tissue samples were collected for immunofluorescence analysis to evaluate the activation of astrocytes and microglia. ResultsThe titer of purified VTT was 1×10⁷ PFU/mL. Compared with the control group, mice in the low-dose group showed no significant change in body weight, and no lethality was observed. In contrast, mice in the high-dose group exhibited significant weight loss starting on day 5 post-infection (P<0.05), accompanied by lethality. On day 13 post-infection, no Evans Blue extravasation was detected in the brain tissues of the low-dose group, while the olfactory bulb region of the high-dose group displayed distinct blue staining, indicating disruption of the BBB. Immunofluorescence analysis revealed no significant proliferation of astrocytes and microglia in the olfactory bulb region of the low-dose group on day 13 post-infection. In contrast, marked activation of glial cells was observable in the high-dose group. ConclusionAn animal model of VTT-induced encephalopathy in AG6 mice is successfully established, characterized by BBB disruption and reactive gliosis specifically localized to the olfactory bulb region, manifested as astrocytic and microglial proliferation.

Objective To address the need for rapid review of automated organ-at-risk (OAR) contouring for head-and-neck cancer in online adaptive radiotherapy, this study used dosimetric indices as the reference standard to evaluate the suitability of geometric similarity metrics and to develop a rapid screening model that balances the risk of missed errors with review efficiency. Methods This retrospective study included 29 patients with head-and-neck radiotherapy, yielding 243 pairs of OAR contours (auto-generated vs. manual). Geometric similarity metrics, including the Dice similarity coefficient (Dice), the 95th percentile Hausdorff distance (HD95), and the maximum Hausdorff distance (HD100), were computed between the two contour sets. Using the dose distributions from clinical treatment plans, dosimetric differences between the two contour sets were calculated for key indices, including mean dose (D_mean) and maximum dose (D_max). Correlations between geometric metrics and dosimetric differences were analyzed. Dosimetric discrepancy events were defined as Y_3Gy using a threshold of 3 Gy. Within a univariable logistic regression triage framework, each geometric metric was used as an independent variable to estimate the probability of Y_3Gy. Discriminative performance was assessed using receiver operating characteristic (ROC) curves and precision-recall (PR) curves, with the area under the curve (AUC) including ROC-AUC and PR-AUC. Practical operating thresholds were determined via threshold sweeping. Results Geometric similarity metrics showed weak-to-moderate correlations with dosimetric differences; compared with maximum dose, correlations with mean dose differences were more consistent. Among the evaluated metrics, HD95 achieved the best classification performance for Y_3Gy. Threshold sweeping suggested that an HD95 threshold in the range of 4-9 mm can balance the risk of missed discrepancies with the efficiency of automated contour quality assurance (QA). Conclusion Several geometric similarity metrics demonstrated only weak-to-moderate associations with dosimetric differences. For head-and-neck OAR contour QA in this study, HD95 provided the best discriminative performance and can support rapid triage of automated contours, with a practical operating threshold range of 4-9 mm, potentially improving the efficiency of adaptive radiotherapy workflows.

Objective To detect the isocenter of a medical linear accelerator using an optical surface monitoring system (OSMS) combined with a self-made 3D-printed phantom, and compare with the conventional front pointer measurement method. Methods A phantom that could be fixed to the front pointer of the accelerator was fabricated using 3D printing technology. The front pointer method and OSMS were used to detect the rotation isocenter deviations of the accelerator. During the experiments, the collimator, gantry, and couch linear displacement readings were recorded at different angles. We also recorded the measurement time of different surveyors. Results Compared to the front pointer measurement method, the OSMS method showed lower standard deviations. The reductions in standard deviations showed statistical significance in the Lat direction for the collimator rotation isocenter as well as in the Lat and Vrt directions for the gantry rotation isocenter. The mean deviation of Mag values for the collimator rotation isocenter using the OSMS method was 0.50 mm, which was larger than the 0.42 mm using the front pointer method. However, the standard deviation was 0.06 using the OSMS method, which was smaller than the 0.18 using the front pointer method. The mean deviation and standard deviation of Sag values for the gantry rotation isocenter using the OSMS method were 1.03 mm and 0.12, respectively, which were both larger than 0.47 mm and 0.06 using the front pointer method. For the couch rotation isocenter, the mean deviation and standard deviation using the OSMS method were 0.32 mm and 0.04, respectively, which were both smaller than the 0.55 mm and 0.20 using the front pointer method. All surveyors spent less time in isocenter measurements using the OSMS method compared to the front pointer method. Conclusion Compared with the front pointer method, the OSMS method significantly reduces the standard deviation among surveyors, effectively reduces the influence of the angle deviation of the accelerator on the measurement results, reduces detection time, improves detection efficiency, and provides a powerful practical basis for the application of OSMS in detecting the mechanical accuracy of the linear accelerator.

Objective To address the need for rapid review of automated organ-at-risk (OAR) contouring for head-and-neck cancer in online adaptive radiotherapy, this study used dosimetric indices as the reference standard to evaluate the suitability of geometric similarity metrics and to develop a rapid screening model that balances the risk of missed errors with review efficiency. Methods This retrospective study included 29 patients with head-and-neck radiotherapy, yielding 243 pairs of OAR contours (auto-generated vs. manual). Geometric similarity metrics, including the Dice similarity coefficient (Dice), the 95th percentile Hausdorff distance (HD95), and the maximum Hausdorff distance (HD100), were computed between the two contour sets. Using the dose distributions from clinical treatment plans, dosimetric differences between the two contour sets were calculated for key indices, including mean dose (D_mean) and maximum dose (D_max). Correlations between geometric metrics and dosimetric differences were analyzed. Dosimetric discrepancy events were defined as Y_3Gy using a threshold of 3 Gy. Within a univariable logistic regression triage framework, each geometric metric was used as an independent variable to estimate the probability of Y_3Gy. Discriminative performance was assessed using receiver operating characteristic (ROC) curves and precision-recall (PR) curves, with the area under the curve (AUC) including ROC-AUC and PR-AUC. Practical operating thresholds were determined via threshold sweeping. Results Geometric similarity metrics showed weak-to-moderate correlations with dosimetric differences; compared with maximum dose, correlations with mean dose differences were more consistent. Among the evaluated metrics, HD95 achieved the best classification performance for Y_3Gy. Threshold sweeping suggested that an HD95 threshold in the range of 4-9 mm can balance the risk of missed discrepancies with the efficiency of automated contour quality assurance (QA). Conclusion Several geometric similarity metrics demonstrated only weak-to-moderate associations with dosimetric differences. For head-and-neck OAR contour QA in this study, HD95 provided the best discriminative performance and can support rapid triage of automated contours, with a practical operating threshold range of 4-9 mm, potentially improving the efficiency of adaptive radiotherapy workflows.

Objective To detect the isocenter of a medical linear accelerator using an optical surface monitoring system (OSMS) combined with a self-made 3D-printed phantom, and compare with the conventional front pointer measurement method. Methods A phantom that could be fixed to the front pointer of the accelerator was fabricated using 3D printing technology. The front pointer method and OSMS were used to detect the rotation isocenter deviations of the accelerator. During the experiments, the collimator, gantry, and couch linear displacement readings were recorded at different angles. We also recorded the measurement time of different surveyors. Results Compared to the front pointer measurement method, the OSMS method showed lower standard deviations. The reductions in standard deviations showed statistical significance in the Lat direction for the collimator rotation isocenter as well as in the Lat and Vrt directions for the gantry rotation isocenter. The mean deviation of Mag values for the collimator rotation isocenter using the OSMS method was 0.50 mm, which was larger than the 0.42 mm using the front pointer method. However, the standard deviation was 0.06 using the OSMS method, which was smaller than the 0.18 using the front pointer method. The mean deviation and standard deviation of Sag values for the gantry rotation isocenter using the OSMS method were 1.03 mm and 0.12, respectively, which were both larger than 0.47 mm and 0.06 using the front pointer method. For the couch rotation isocenter, the mean deviation and standard deviation using the OSMS method were 0.32 mm and 0.04, respectively, which were both smaller than the 0.55 mm and 0.20 using the front pointer method. All surveyors spent less time in isocenter measurements using the OSMS method compared to the front pointer method. Conclusion Compared with the front pointer method, the OSMS method significantly reduces the standard deviation among surveyors, effectively reduces the influence of the angle deviation of the accelerator on the measurement results, reduces detection time, improves detection efficiency, and provides a powerful practical basis for the application of OSMS in detecting the mechanical accuracy of the linear accelerator.

Objective To address the need for rapid review of automated organ-at-risk (OAR) contouring for head-and-neck cancer in online adaptive radiotherapy, this study used dosimetric indices as the reference standard to evaluate the suitability of geometric similarity metrics and to develop a rapid screening model that balances the risk of missed errors with review efficiency. Methods This retrospective study included 29 patients with head-and-neck radiotherapy, yielding 243 pairs of OAR contours (auto-generated vs. manual). Geometric similarity metrics, including the Dice similarity coefficient (Dice), the 95th percentile Hausdorff distance (HD95), and the maximum Hausdorff distance (HD100), were computed between the two contour sets. Using the dose distributions from clinical treatment plans, dosimetric differences between the two contour sets were calculated for key indices, including mean dose (D_mean) and maximum dose (D_max). Correlations between geometric metrics and dosimetric differences were analyzed. Dosimetric discrepancy events were defined as Y_3Gy using a threshold of 3 Gy. Within a univariable logistic regression triage framework, each geometric metric was used as an independent variable to estimate the probability of Y_3Gy. Discriminative performance was assessed using receiver operating characteristic (ROC) curves and precision-recall (PR) curves, with the area under the curve (AUC) including ROC-AUC and PR-AUC. Practical operating thresholds were determined via threshold sweeping. Results Geometric similarity metrics showed weak-to-moderate correlations with dosimetric differences; compared with maximum dose, correlations with mean dose differences were more consistent. Among the evaluated metrics, HD95 achieved the best classification performance for Y_3Gy. Threshold sweeping suggested that an HD95 threshold in the range of 4-9 mm can balance the risk of missed discrepancies with the efficiency of automated contour quality assurance (QA). Conclusion Several geometric similarity metrics demonstrated only weak-to-moderate associations with dosimetric differences. For head-and-neck OAR contour QA in this study, HD95 provided the best discriminative performance and can support rapid triage of automated contours, with a practical operating threshold range of 4-9 mm, potentially improving the efficiency of adaptive radiotherapy workflows.

Objective To detect the isocenter of a medical linear accelerator using an optical surface monitoring system (OSMS) combined with a self-made 3D-printed phantom, and compare with the conventional front pointer measurement method. Methods A phantom that could be fixed to the front pointer of the accelerator was fabricated using 3D printing technology. The front pointer method and OSMS were used to detect the rotation isocenter deviations of the accelerator. During the experiments, the collimator, gantry, and couch linear displacement readings were recorded at different angles. We also recorded the measurement time of different surveyors. Results Compared to the front pointer measurement method, the OSMS method showed lower standard deviations. The reductions in standard deviations showed statistical significance in the Lat direction for the collimator rotation isocenter as well as in the Lat and Vrt directions for the gantry rotation isocenter. The mean deviation of Mag values for the collimator rotation isocenter using the OSMS method was 0.50 mm, which was larger than the 0.42 mm using the front pointer method. However, the standard deviation was 0.06 using the OSMS method, which was smaller than the 0.18 using the front pointer method. The mean deviation and standard deviation of Sag values for the gantry rotation isocenter using the OSMS method were 1.03 mm and 0.12, respectively, which were both larger than 0.47 mm and 0.06 using the front pointer method. For the couch rotation isocenter, the mean deviation and standard deviation using the OSMS method were 0.32 mm and 0.04, respectively, which were both smaller than the 0.55 mm and 0.20 using the front pointer method. All surveyors spent less time in isocenter measurements using the OSMS method compared to the front pointer method. Conclusion Compared with the front pointer method, the OSMS method significantly reduces the standard deviation among surveyors, effectively reduces the influence of the angle deviation of the accelerator on the measurement results, reduces detection time, improves detection efficiency, and provides a powerful practical basis for the application of OSMS in detecting the mechanical accuracy of the linear accelerator.

AKT,also known as Protein Kinase B(PKB),plays a critical role in cell proliferation and metabolism.There are three isoforms of AKT:AKT1,AKT2,and AKT3.The effects of these isoforms on the pluripotency and differentiation of mouse embryonic stem cells(mESCs)remain unclear.This study aims to explore the impact of three AKT isoform-specific knockouts on the self-renewal and differen-tiation of mouse embryonic stem cells.Using CRISPR/Cas9 gene-editing technology,AKT isoform-spe-cific knockout cell lines were established.The phenotypic and molecular changes were analyzed through Western blotting,flow cytometry,qRT-PCR,CCK-8 assays,Alkaline Phosphatase(AP)staining,and RNA-seq.The construction of AKT isoform-specific knockout cell lines was successful.The loss of AKT1 and AKT2 inhibited the proliferation of mESCs.The knockout of any single AKT isoform did not affect the expression of pluripotency genes at both mRNA or protein levels.However,during embryoid body forma-tion,the deletion of any of the three AKT isoforms affected the mRNA expression levels of genes in all three germ layers.Transcriptome analysis showed that compared to wild-type mESCs,995,547,and 429 differentially expressed genes(|log2FC|≧1,P＜0.05)were identified inAKT1,AKT2,and AKT3 isoform-specific knockout cells,respectively.There was some overlap in the differentially expressed genes regulated by these three isoforms.In conclusion,the independent knockout of AKT isoforms does not af-fect the maintenance of pluripotency in mouse embryonic stem cells,but they are crucial for differentia-tion.The three AKT isoforms can collectively regulate gene expression while retaining their own regulato-ry specificity.This study provides a foundation for understanding the unique and overlapping roles of AKT isoforms in stem cell biology,highlighting their importance in maintaining stem cell function and differen-tiation.

Objective To construct mouse models of vaccinia virus infection using C57BL/6N and BALB/C mice infected with vaccinia virus VR-1354(WR(NIH TC-adapted)),and to compare the differences between the models in the two mouse strains.Methods Vaccinia virus VR-1354 was amplified,concentrated,and titrated,according to conventional method.The median lethal doses(LD50)of vaccinia virus V R-1354 for C57BL/6N and BALB/C mice were determined,respectively,and mice from the two strains were infected with the respective LD50.Lung tissues from control and experimental mice were removed for hematoxylin and eosin staining on days 3,7,and 14,and changes in the virus load in the lung tissues were measured at the same times.Results The titer of the amplified vaccinia virus VR-1354 was 3×108 plaque forming units(PFU)/mL.The LD50 values in C57BL/6N and BALB/C mice were 2.5×103and BALB/C 2.8×103PFU,respectively.After infecting mice from both strains with 2.5× 103 PFU of vaccinia virus VR 1354,lung tissue lesions worsened with increasing infection time,but the symptoms of the mice tended to recover after day 7.The virus loads in lung tissues began to increase on day 3 in both strains,peaked on day 7,and then gradually decreased.Conclusions C57BL/6N and BALB/C mouse models infected with vaccinia virus VR-1354 were established successfully.The virus can cause obvious lesions in mouse lung tissues,including inflammatory cell infiltration and alveolar cavity fluid exudation.The degree of disease onset and susceptibility differed between the two mouse strains,with C57BL/6N mice showing higher susceptibility to this virus than BALB/C mice.