OBJECTIVE To establish a preparation system for megakaryocytes(MKs)derived from human embryonic stem cells(hESCs)and MK microparticles(MKMPs),and to assess the pro-angio-genic efficiency of these microparticles.METHODS ①hESCs were induced to mesodermal progenitor cells via monolayer culture with the first-stage induction medium for 2 days before the cells were induced to hemogenic endothelial/hematopoietic progenitor cells by culturing with the second-stage induction medium for another 3 days.Then,the cells were dissociated into single cells,seeded into the third-stage induction medium,and cultured using the suspension method for 8 days to obtain MKs.The specific characters of differentiated cells were identified through morphological observation and flow cytometry before stage-specific marker proteins in different periods were analyzed[hESCs:TRA-1-60,sialyl glycolipid stage-specific embryonic antigen4(SSEA4)];mesodermal progenitor cells:brachyury;hemogenic endothelial/hematopoietic progenitor cells:CD34,CD43;MKs:CD41a,CD42b),and immu-nofluorescence staining[β1-tubulin,von Willebrand factor(VWF)],[friend leukemia integration 1(FLI1),CD42].② MKMP collection and verification:MKMPs were collected via differential centrifugation.The concentration and size of these MKMPs were determined by nanoparticle tracking analysis(NTA),and both the morphology and ultrastructure were examined by transmission electron microscopy(TEM).Besides,the MKMPs-specific proteins[CD41,tumor susceptibility gene 101(TSG101)and CD9]were detected by Western blotting analysis.③ Biological function of MKMPs:MKMPs were stained with CD41a-PE antibodies and co-cultured with human umbilical veinvascular endothelial cells(HUVECs)labeled by CD34-APC for 3 h.Live-cell immunofluorescence was employed to find out whether HUVECs could absorb MKMPs.To find out whether MKMPs could affect the role of HUVECs in angio-genesis and cell migration,platelet microvesicles(PMPs)were used as positive controls.The experi-mental groups were added with different concentrations of microparticles(1,5,10 and 20 mg·L-1)while the control group was given no microparticles(0 mg·L-1).The number of nodes that formed the lumen after 5 h of incubation in Matrigel was counted,and the size of healing of the scratch area was analyzed after 6 h.To elucidate the mechanism through which MKMPs impacted angiogenesis,ELISA was used out to quantitatively detect the concentration of proteins in microparticles.RESULTS ① A three-stage differentiation cultural system was established to develop hESCs into MKs.Flow cytometry revealed progressive loss of pluripotency markers SSEA4 and TRA-1-60,while the mesodermal progenitor marker brachyury peaked at d 2.Subsequently,hemogenic endothelial/hematopoietic progenitor markers CD34 and CD43 emerged at d 5,followed by megakaryocytic markers CD41a and CD42b at d 13.Immunofluorescent images further demonstrated that MKs expressed specific proteins CD42,β1-tubulin,von VWF and FLI1 at d 13.②Microparticles were collected via differential centrifuga-tion.Transmission electron microscopy revealed that their substructure exhibited a typical double-layered membrane.Nanoparticle tracking analysis indicated that the size was(164.3±14.0)nm.The result of WB demonstrated that the microparticles expressed specific markers,including TSG101,CD9 and CD41.③ MKMPs were absorbed after being co-cultured with HUVECs for 3 h and enhanced the ability of HUVECs to form tubes and migrate.Notably,the treatment of 5 mg·L-1 MKMPs was more effective than 5 mg·L-1 PMPs treatment.The results of ELISA showed that the content of VEGF from MKMPs was higher than from PMPs,which may be the key factor in regulating endothelial biological function.CONCLUSION MKs derived from hESCs can generate functional microparticles which can promote angiogenesis.

OBJECTIVE To establish a preparation system for megakaryocytes(MKs)derived from human embryonic stem cells(hESCs)and MK microparticles(MKMPs),and to assess the pro-angio-genic efficiency of these microparticles.METHODS ①hESCs were induced to mesodermal progenitor cells via monolayer culture with the first-stage induction medium for 2 days before the cells were induced to hemogenic endothelial/hematopoietic progenitor cells by culturing with the second-stage induction medium for another 3 days.Then,the cells were dissociated into single cells,seeded into the third-stage induction medium,and cultured using the suspension method for 8 days to obtain MKs.The specific characters of differentiated cells were identified through morphological observation and flow cytometry before stage-specific marker proteins in different periods were analyzed[hESCs:TRA-1-60,sialyl glycolipid stage-specific embryonic antigen4(SSEA4)];mesodermal progenitor cells:brachyury;hemogenic endothelial/hematopoietic progenitor cells:CD34,CD43;MKs:CD41a,CD42b),and immu-nofluorescence staining[β1-tubulin,von Willebrand factor(VWF)],[friend leukemia integration 1(FLI1),CD42].② MKMP collection and verification:MKMPs were collected via differential centrifugation.The concentration and size of these MKMPs were determined by nanoparticle tracking analysis(NTA),and both the morphology and ultrastructure were examined by transmission electron microscopy(TEM).Besides,the MKMPs-specific proteins[CD41,tumor susceptibility gene 101(TSG101)and CD9]were detected by Western blotting analysis.③ Biological function of MKMPs:MKMPs were stained with CD41a-PE antibodies and co-cultured with human umbilical veinvascular endothelial cells(HUVECs)labeled by CD34-APC for 3 h.Live-cell immunofluorescence was employed to find out whether HUVECs could absorb MKMPs.To find out whether MKMPs could affect the role of HUVECs in angio-genesis and cell migration,platelet microvesicles(PMPs)were used as positive controls.The experi-mental groups were added with different concentrations of microparticles(1,5,10 and 20 mg·L-1)while the control group was given no microparticles(0 mg·L-1).The number of nodes that formed the lumen after 5 h of incubation in Matrigel was counted,and the size of healing of the scratch area was analyzed after 6 h.To elucidate the mechanism through which MKMPs impacted angiogenesis,ELISA was used out to quantitatively detect the concentration of proteins in microparticles.RESULTS ① A three-stage differentiation cultural system was established to develop hESCs into MKs.Flow cytometry revealed progressive loss of pluripotency markers SSEA4 and TRA-1-60,while the mesodermal progenitor marker brachyury peaked at d 2.Subsequently,hemogenic endothelial/hematopoietic progenitor markers CD34 and CD43 emerged at d 5,followed by megakaryocytic markers CD41a and CD42b at d 13.Immunofluorescent images further demonstrated that MKs expressed specific proteins CD42,β1-tubulin,von VWF and FLI1 at d 13.②Microparticles were collected via differential centrifuga-tion.Transmission electron microscopy revealed that their substructure exhibited a typical double-layered membrane.Nanoparticle tracking analysis indicated that the size was(164.3±14.0)nm.The result of WB demonstrated that the microparticles expressed specific markers,including TSG101,CD9 and CD41.③ MKMPs were absorbed after being co-cultured with HUVECs for 3 h and enhanced the ability of HUVECs to form tubes and migrate.Notably,the treatment of 5 mg·L-1 MKMPs was more effective than 5 mg·L-1 PMPs treatment.The results of ELISA showed that the content of VEGF from MKMPs was higher than from PMPs,which may be the key factor in regulating endothelial biological function.CONCLUSION MKs derived from hESCs can generate functional microparticles which can promote angiogenesis.

Objective:To develop and evaluate a medical visual question answering (VQA) model for neonatal lung ultrasound (LUS) images to enhance intelligent auxiliary diagnosis of neonatal pulmonary diseases.Methods:Using data from neonates admitted to Beijing Obstetrics and Gynecology Hospital, Capital Medical University (January 2023 to December 2024), an image-question-answer dataset comprising 251 LUS images was constructed [43 pneumonia (17.1%), 42 neonatal respiratory distress syndrome (16.7%), 83 transient tachypnea (33.1%), and 83 normal (33.1%) images] with a four-tier medical question-answer framework. Building upon the Qwen2.5-VL-7B base model and integrating LoRA fine-tuning with chain-of-thought prompting, we developed the NLUS-VQA model to enhance visual-language semantic alignment and enable stepwise clinical reasoning, achieving efficient small-sample adaptation. Model performance was comprehensively assessed through natural language generation metrics (BLEU-4, ROUGE-1/2/L), qualitative evaluation of characteristic recognition, and clinical consistency analysis.Results:(1) Quantitative evaluation demonstrated that NLUS-VQA achieved scores of 22.38 (BLEU-4), 48.26 (ROUGE-1), 22.40 (ROUGE-2), and 37.20 (ROUGE-L), representing significant improvements over baseline models. (2) Qualitatively, the model exhibited strong performance in identifying lung consolidation, coalescent B-lines, and snowflake signs, with its chain-of-thought strategy enhancing clinical interpretability and answer accuracy. (3) Clinically, NLUS-VQA achieved a Cohen's Kappa coefficient of 0.78 and diagnostic accuracy of 80.8% (21/26), indicating substantial agreement with clinical experts.Conclusion:The NLUS-VQA model demonstrates robust interpretability in recognizing key sonographic patterns (e.g. lung consolidation, confluent B-lines, and snowflake signs), providing a scalable framework for small-sample medical image analysis, though diagnostic performance on complex conditions remains limited by dataset scale and minority class representation.

Objective:To illustrate the clinical modeling and commissioning results of Monte Carlo dose calculation algorithm in RayStation treatment planning system (TPS) for a domestically developed synchrotron-based spot scanning proton therapy system (SAPT-PS-01).Methods:The proton pencil beam model in RayStation required integral depth dose curves, spot profiles and absolute dose as the input beam data. It was not necessary to collect beam parameters with range shifter. The integral depth dose curves of a single spot were measured by an 8 cm parallel ion chamber. A 2-dimensional scintillation detector was used to measure the in-air spot profile at 5 different depths including the isocenter plane. The absolute dose was calibrated by a 0.25 cm parallel ion chamber under the single energy layer irradiation with a field size of 10 cm × 10 cm. After modeling, the results of the beam model and the Monte Carlo dose calculation algorithm were validated from the range, spot profile, point-dose in a spread-out Bragg peak, planar dose in a clinical plan, point dose in an end-to-end test.Results:For the 94 energy layers, the maximum deviation between the calculated and measured range was 0.03 cm. The maximum difference between the calculated and measured in-air spot sigma was 0.015 cm, and the deviation of in-water spot sigma was measured within ±15%. Compared with the measured values, the calculated dose deviation of 138 measured points in the spread-out Bragg peak was within 3%. For the planar dose verification of clinical plans, the TPS-calculated dose distribution of 285 planes agreed well with the measurement with a minimum gamma-passing rate of 90%, and the gamma passing rate of almost 95% of planes were greater than 95%. The point dose measurements for 8 beams in the end-to-end tests under 4 clinical scenarios were within 5%.Conclusions:The acceptable beam model validation results and successful end-to-end test confirm that the Monte Carlo dose calculation algorithm modeling for the synchrotron-based spot scanning proton therapy system is accurate, which is applicable for the design of patient treatment plan.

Objective:To develop and evaluate a medical visual question answering (VQA) model for neonatal lung ultrasound (LUS) images to enhance intelligent auxiliary diagnosis of neonatal pulmonary diseases.Methods:Using data from neonates admitted to Beijing Obstetrics and Gynecology Hospital, Capital Medical University (January 2023 to December 2024), an image-question-answer dataset comprising 251 LUS images was constructed [43 pneumonia (17.1%), 42 neonatal respiratory distress syndrome (16.7%), 83 transient tachypnea (33.1%), and 83 normal (33.1%) images] with a four-tier medical question-answer framework. Building upon the Qwen2.5-VL-7B base model and integrating LoRA fine-tuning with chain-of-thought prompting, we developed the NLUS-VQA model to enhance visual-language semantic alignment and enable stepwise clinical reasoning, achieving efficient small-sample adaptation. Model performance was comprehensively assessed through natural language generation metrics (BLEU-4, ROUGE-1/2/L), qualitative evaluation of characteristic recognition, and clinical consistency analysis.Results:(1) Quantitative evaluation demonstrated that NLUS-VQA achieved scores of 22.38 (BLEU-4), 48.26 (ROUGE-1), 22.40 (ROUGE-2), and 37.20 (ROUGE-L), representing significant improvements over baseline models. (2) Qualitatively, the model exhibited strong performance in identifying lung consolidation, coalescent B-lines, and snowflake signs, with its chain-of-thought strategy enhancing clinical interpretability and answer accuracy. (3) Clinically, NLUS-VQA achieved a Cohen's Kappa coefficient of 0.78 and diagnostic accuracy of 80.8% (21/26), indicating substantial agreement with clinical experts.Conclusion:The NLUS-VQA model demonstrates robust interpretability in recognizing key sonographic patterns (e.g. lung consolidation, confluent B-lines, and snowflake signs), providing a scalable framework for small-sample medical image analysis, though diagnostic performance on complex conditions remains limited by dataset scale and minority class representation.

Objective:To illustrate the clinical modeling and commissioning results of Monte Carlo dose calculation algorithm in RayStation treatment planning system (TPS) for a domestically developed synchrotron-based spot scanning proton therapy system (SAPT-PS-01).Methods:The proton pencil beam model in RayStation required integral depth dose curves, spot profiles and absolute dose as the input beam data. It was not necessary to collect beam parameters with range shifter. The integral depth dose curves of a single spot were measured by an 8 cm parallel ion chamber. A 2-dimensional scintillation detector was used to measure the in-air spot profile at 5 different depths including the isocenter plane. The absolute dose was calibrated by a 0.25 cm parallel ion chamber under the single energy layer irradiation with a field size of 10 cm × 10 cm. After modeling, the results of the beam model and the Monte Carlo dose calculation algorithm were validated from the range, spot profile, point-dose in a spread-out Bragg peak, planar dose in a clinical plan, point dose in an end-to-end test.Results:For the 94 energy layers, the maximum deviation between the calculated and measured range was 0.03 cm. The maximum difference between the calculated and measured in-air spot sigma was 0.015 cm, and the deviation of in-water spot sigma was measured within ±15%. Compared with the measured values, the calculated dose deviation of 138 measured points in the spread-out Bragg peak was within 3%. For the planar dose verification of clinical plans, the TPS-calculated dose distribution of 285 planes agreed well with the measurement with a minimum gamma-passing rate of 90%, and the gamma passing rate of almost 95% of planes were greater than 95%. The point dose measurements for 8 beams in the end-to-end tests under 4 clinical scenarios were within 5%.Conclusions:The acceptable beam model validation results and successful end-to-end test confirm that the Monte Carlo dose calculation algorithm modeling for the synchrotron-based spot scanning proton therapy system is accurate, which is applicable for the design of patient treatment plan.

Pain not only affects the physical and mental health of individuals, but also imposes a huge burden on society as a whole. Traditional pain management measures are diverse, but each has its limitations. Therefore, there is an urgent need for new tools. Digital therapies are booming, and virtual reality (VR) has been widely used, especially in the field of pain management. VR uses assistive tools, such as headsets, to build a three-dimensional virtual world with the participation of multiple senses, including vision, hearing, and smell, so that it can make user feel being there. This review aims to summarize the application and mechanism of VR in the field of pain management, with the hope of making VR a new choice for pain management.

Objective To analyze influencing factors of paclitaxel coated ballon(PCB)on long-term restenosis in patients with severe subpatellar artery lesions in type 2 diabetes mellitus(T2DM),and to construct a prediction model.Methods A total of 268 T2DM patients with severe infra-popliteal artery disease and received PCB treatment were selected.Patients were followed up for 1 year after treatment.Patients with target vessel restenosis were included in the observation group,and the other patients were included in the control group.Clinical data of two groups were analyzed.Multivariable Logistic regression analysis was used to analyze influencing factors of long-term restenosis in T2DM patients with severe infra-knee arterial disease,and a nomogram prediction model was constructed.Results A total of 260 patients(97.00%)completed the follow-up,and the incidence of restenosis was 13.85%(36/260).Both univariate and multivariate Logistic regression analysis showed that age,coexisting coronary heart disease,Trans-Atlantic Inter-Society Consensus(TASC)Ⅱ classification,Fontaine staging,glycosylated hemoglobin(HbA1c)and low density lipoprotein cholesterol(LDL-C)were independent influencing factors for the occurrence of long-term restenosis in T2DM patients with severe infra-popliteal artery disease(P<0.05).The risk factor with the highest score in the constructed nomogram prediction model was HbA1c,followed by age,LDL-C,TASCⅡ classification,Fontaine stage and coronary heart disease.According to the column chart,the total score was 210 points,and the probability of long-term restenosis was 90%.The discrimination of the nomogram model was 0.866,with a Brier score of 0.081 and a calibration slope of 0.733.When the risk threshold was 0.15 to 1.0,the net benefit rate of long-term restenosis in T2DM patients with severe infra-popliteal artery disease was greater than that of individual evaluation.The smaller the risk threshold,the greater the net benefit rate.The benefit was the best when the threshold reached 0.23.Conclusion The influencing factors for long-term restenosis in T2DM patients with severe subknee artery disease treated by PCB include age,combined coronary heart disease,TASCⅡ grade,Fontaine stage,HbA1c and LDL-C.The prediction model based on the above influencing factors has important value in predicting long-term restenosis in patients.

Objective:To analyze the medium- and long-term outcomes of V-Y quadricepsplasty in primary total knee arthroplasty (TKA) to expose an ankylosed or stiff knee joint.Methods:From May 2010 to February 2019, a total of 12 patients with TKA revealed by V-Y quadricepsplasty in West China Hospital of Sichuan University due to knee ankylosis or stiffness were retrospectively analyzed, including 7 males and 5 females, aged (53.9±14.9) years (range, 24 to 72 years), 6 patients on the left side and 6 patients on the right side. Preoperative diagnosis: 7 cases of osteoarthritis, 2 cases of rheumatoid arthritis, 1 case of traumatic arthritis, and 2 cases of haemophilic arthritis. Visual analogue scale (VAS), range of motion, quadriceps muscle strength, Knee Society score (KSS) and postoperative complications were recorded before and after operation.Results:All patients successfully completed the operation and were followed up for 102.2±31.1 months (range, 51-141 months). The operation time was 87.0±15.7 min (range, 73 to 123 min), the intraoperative blood loss was 823.6±237.7 ml (range, 555 to 1 471 ml), and the hospital stay was 13.3±6.3 d (range, 6 to 28 d). Postoperative VAS scores were decreased in all patients, and the difference before and after operation was statistically significant ( F=132.000, P<0.001). The VAS scores at 3 months and the last follow-up were 2.2±0.7 points and 1.2±0.4 points, respectively, lower than those before operation (5.2±0.7 points), and the difference was statistically significant ( P<0.05). KSS knee scores were higher in all patients after operation, and the difference was statistically significant before and after operation ( F=40.960, P<0.001). KSS knee scores at 3 months and the last follow-up were 56.0±14.1 points and 74.3±16.1 points, respectively, higher than those before operation (26.1±7.8 points), and the difference was statistically significant ( P<0.05). Postoperative KSS functional scores were increased in all patients, and the difference before and after operation was statistically significant ( F=24.332, P<0.001). The KSS functional scores at 3 months and the last follow-up were 52.9±19.4 points and 79.2±19.6 points, respectively, higher than those before operation (27.1±15.6 points), and the difference was statistically significant ( P<0.05). Postoperative knee joint motion was increased in all patients, and the difference was statistically significant before and after operation ( F=24.145, P<0.001). The range of motion of the knee joint at 3 months and the last follow-up was 57.5°±22.2° and 70.0°±25.9°, respectively, which was higher than the preoperative 12.5°±14.1°, and the difference was statistically significant ( P<0.05). Preoperative quadriceps muscle strength was grade 3 in 2 cases and grade 4 in 10 cases; at the last follow-up, grade 4 in 1 case and grade 5 in 11 cases, and the muscle strength was improved compared with that before operation, the difference was statistically significant ( Z=11.000, P<0.001). At the last follow-up, there were no complications such as wound seepage, delayed healing, superficial or deep soft tissue infection, periprosthesis infection and loosening, deep vein thrombosis and pulmonary embolism. Conclusion:In patients with ankylosed or stiff knee receiving TKA, the use of V-Y quadricepsplasty can increase the exposure, thereby improving the range of knee motion and quadriceps muscle strength.

Objective To compare the effects of different respiratory signal acquisition methods on the delineation of moving tumor targets. Methods A cube phantom containing a sphere was placed on a motion platform to simulate respiratory movement by setting motion period, frequency, and direction. Respiratory signal was acquired by real-time position management (RPM) method and GE method independently. Target delineation was conducted using the maximum intensity projection (MIP) sequence. The difference between the reconstructed volume and the theoretical moving volume was compared under the two respiratory signal acquisition methods for cube and sphere targets. Results Under the same respiratory signal acquisition method, the same respiratory amplitude, and different respiratory frequencies, reconstructed volume changes were relatively small. For the sphere target, the deviation between the reconstructed volume and the theoretical moving volume was −1.5% to 5.7% with the RPM method and −1.3% to −13.8% with the GE method (both P < 0.05). For the cube target, the deviation between the reconstructed volume and the theoretical moving volume was 0.2% to 0.9% with the RPM method and −2.6% to 0.9% with the GE method, with no statistical significance. Conclusion For small-volume sphere targets, the target volumes obtained from MIP images by the two respiratory signal acquisition methods are both smaller than the actual moving volume. For large-volume cube targets, there is no significant difference between the reconstructed and theoretical results with any respiratory signal acquisition method. The RPM method produces smaller deviation and better image quality when reconstructing small-volume targets.