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 systematically examine research progress and evolutionary trajectories of public hospitals in China in digital intelligence era,providing foundational references for digital intelligence management studies.Methods Based on papers published in core journals indexed by China National Knowledge Infrastructure(CNKI)from January 2018 to Septem-ber 2024,including those from Peking University Core,CSCD,and CSSCI journals,we conducted a visualized analysis using CiteSpace 6.2.R6 software.The analysis covered publication trends,collaboration networks,research hotspots,and core topics in the field of public hospital management research in the digital intelligence era.Results A total of 385 papers were finally in-cluded,the publication exhibiting an upward trend in number.The authors and affiliations were relatively independent.Such top-ics as"high-quality development""informatization""big data",and"smart hospital"were the predominant hotspots in public hospital management research in China.The research themes included high-quality development of public hospitals,big data ap-plications,and digital transformation and upgrading.Conclusion Smart hospital development remains to be a key research fo-cus.Enhanced interdisciplinary collaboration,methodology innovation,and multidimensional perspectives are recommended to advance hospital digitalization.

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 systematically examine research progress and evolutionary trajectories of public hospitals in China in digital intelligence era,providing foundational references for digital intelligence management studies.Methods Based on papers published in core journals indexed by China National Knowledge Infrastructure(CNKI)from January 2018 to Septem-ber 2024,including those from Peking University Core,CSCD,and CSSCI journals,we conducted a visualized analysis using CiteSpace 6.2.R6 software.The analysis covered publication trends,collaboration networks,research hotspots,and core topics in the field of public hospital management research in the digital intelligence era.Results A total of 385 papers were finally in-cluded,the publication exhibiting an upward trend in number.The authors and affiliations were relatively independent.Such top-ics as"high-quality development""informatization""big data",and"smart hospital"were the predominant hotspots in public hospital management research in China.The research themes included high-quality development of public hospitals,big data ap-plications,and digital transformation and upgrading.Conclusion Smart hospital development remains to be a key research fo-cus.Enhanced interdisciplinary collaboration,methodology innovation,and multidimensional perspectives are recommended to advance hospital digitalization.

Objective To validate the performance of droplet digital polymerase chain reaction (ddPCR) reagents using clinical and standard strains, and to evaluate the effectiveness and practicability of ddPCR technology in clinical applications. Methods The concordance rate, specificity, precision, and lower limit of detection of the ddPCR kit were validated using clinical and standard strains. Blood samples from 74 patients with suspected bloodstream infections were collected, and both ddPCR and blood culture methods were used to determine the pathogens in the patient's blood samples. Results The average detection time of ddPCR for pathogens of bloodstream infection was 3.5 hours, which was able to complete the detection of over a dozen common pathogens simultaneously. The concordance rate, specificity, precision, and lower limit of detection of the ddPCR kit for bloodstream infection pathogens all met clinical requirements. Among the 74 patients with suspected bloodstream infections, the positive detection rate using the ddPCR method was 64.86%, while was 40.54% using blood culture, with a statistically significant difference (P < 0.05). Conclusion The method of ddPCR can detect common pathogens of bloodstream infections rapidly, efficiently, and in large quantities, and its main detection performance can meet clinical needs. The combination of blood culture and ddPCR technology is conductive to early and rapid diagnosis of clinical bloodstream infection patients.

Objective To observe the value of 5.0T MRI for quantifying proton density fat fraction(PDFF)of liver.Methods Liver chemical shift encoded(CSE)MR scanning were prospectively performed using 5.0T,3.0T and 1.5T scanner in 30 volunteers,respectively,and CSE-PDFF were measured.Then MR spectroscopy(MRS)were performed using 5.0T and 1.5T scanner,respectively,and MRS-PDFF were also measured.The consistency of liver PDFF measured on different images was observed,and the value of 5.0T MRI for liver PDFF was analyzed.Results The overall consistencies of liver CSE-PDFF measured with 5.0T,3.0T and 1.5T MR scanner were all good(all ICC＞0.75,all P＜0.001).The consistency of liver CSE-PDFF based on 5.0T and 3.0T,1.5T MR scanner were both good(ICC=0.989,0.992,both P＜0.001).The overall consistencies of CSE-PDFF based on 5.0T MR and MRS-PDFF based on 5.0T and 1.5T MR were both good(both ICC＞0.75,both P＜0.001).CSE-PDFF had good consistency with MRS-PDFF based on same 5.0T MR scanner(ICC=0.988,P＜0.001),and CSE-PDFF based on 5.0T had good consistency with MRS-PDFF based on 1.5T MR scanner(ICC=0.978,P＜0.001).Conclusion 5.0T MRI had high value for quantifying liver PDFF.

Objective To observe the consistency of 5.0T and 1.5T MR spectroscopy(MRS)for quantitating proton density fat fraction(PDFF)of liver.Methods Lipid emulsion models with lipid content of 0,5％,10％,15％,20％,25％and 30％were prepared.1H-MRS were collected using 5.0T and 1.5T MR scanners,respectively,and PDFF were obtained with jMRUI software.Totally 23 people,including 11 cases of fatty liver and 12 healthy adults were prospectively collected,and volume of interest(VOI)in the liver were selected to acquire 1H-MRS,and PDFF were obtained with jMRUI software and corresponding workstation,respectively.The consistencies of PDFF measured with different methods were analyzed.Results PDFF of lipid emulsion models with lipid content of 0,5％,10％,15％,20％,25％and 30％measured with jMRUI software and workstations based on 5.0T and 1.5T 1H-MRS all had good consistencies and being positively correlated,so were PDFF of liver tissue measured with jMRUI software and workstations based on 5.0T and 1.5T 1H-MRS.Conclusion 5.0T and 1.5T 1H-MRS had good consistency for quantitating liver PDFF.Measuring liver PDFF with workstation in clinical practice was helpful to simplifying workflow.

Objective To construct and preliminarily apply a graded exercise rehabilitation program for patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD),and to provide a theoretical basis for the scientific implementation of exercise rehabilitation by medical staff.Methods Based on Triangle model and evidence-based method,the first draft of the graded exercise rehabilitation program was constructed,and the items were revised through 2 rounds of expert consultations from March to October,2023.The graded exercise rehabilitation program was preliminarily applied in 10 patients with AECOPD.Results The effective recovery rates of the 2 rounds of expert consultation questionnaires were 100％;the expert authority coefficients were 0.857 and 0.863;the coefficients of variation were 0-0.285 and 0.052-0.244;the Kendall's harmony coefficients were 0.167 and 0.145,respectively(all P＜0.001).The final plan includes 4 first-level indicators,13 second-level indicators,and 25 third-level indicators.The scores of 6 min walking test,mMRC and CAT after exercise were improved compared with those before exercise,and the differences were statistically significant(all P＜0.05).Conclusion The graded exercise rehabilitation program for patients with AECOPD constructed in this study has good scientificity and practicability,which can provide references for clinical implementation of exercise rehabilitation.

Objective:To observe the effect of high expression of polypyrimidine tract-binding protein-associated splicing factor (PSF) on low concentration of 4-hydroxynonenal (4-HNE) induced human retinal microvascular endothelial cells (HRMECs), and explore the possible mechanism.Methods:The HRMECs cultured in vitro were divided into 4-HNE treated group, PSF overexpression group combined with 4-HNE group (PSF+4-HNE group), PSF overexpression+ML385 treatment combined with 4-HNE group (PSF+ML385+4-HNE group), and 4-HNE induced PSF overexpression group with LY294002 pretreatment (LY294002+4-HNE+PSF group). Cell culture medium containing 10 μmmol/L 4-HNE was added into 4-HNE treatment group, PSF+4-HNE group, PSF+ML385+4-HNE group for 12 hours to stimulate oxidative stress. 1.0 μg of pcDNA-PSF eukaryotic expression plasmid were transfected into PSF+4-HNE group and PSF+ML385+4-HNE group to achieve the overexpression of PSF. Also cells were pretreated with ML385 (5 μmol/L) for 48 hours in the PSF+ML385+4-HNE group, meanwhile within the LY294002+4-HNE+PSF group, after pretreatment with LY294002, cells were treated with plasmid transfection and 4-HNE induction. Transwell detects the migration ability of PSF to HRMECs. The effect of PSF on the lumen formation of HRMECs was detected by using Matrigel in vitro three-dimensional molding method. Flow cytometer was used to detect the effect of PSF overexpression on reactive oxygen (ROS) level in HRMECs. Protein immunoblotting was used to detect the relative expression of PSF, nuclear factor E2 related factor 2 (Nrf2), heme oxygenase-1 (HO-1) protein, and phosphoserine threonine protein kinase (pAkt) protein. The comparison between the two groups was performed using a t-test. Results:The number of live cells, migrating cells, and intact lumen formation in the 4-HNE treatment group and the PSF+4-HNE group were 1.70±0.06, 0.80±0.13, 24.00±0.58, 10.00±0.67, and 725.00±5.77, 318.7±12.13, respectively. There were significant differences in the number of live cells, migrating cells, and intact lumen formation between the two groups ( t=12.311, 15.643, 17.346; P<0.001). The results of flow cytometry showed that the ROS levels in the 4-HNE treatment group, PSF+4-HNE group, and PSF+ML385+4-HNE group were 816.70±16.67, 416.70±15.44, and 783.30±17.41, respectively. There were statistically significant differences between the two groups ( t=16.311, 14.833, 18.442; P<0.001). Western blot analysis showed that the relative expression levels of pAkt, Nrf2, and HO-1 proteins in HRMECs in the 4-HNE treatment group, PSF+4-HNE group and LY294002+4-HNE+PSF group were 0.08±0.01, 0.57±0.04, 0.35±0.09, 0.17±0.03, 1.10±0.06, 0.08±0.11 and 0.80±0.14, 2.50±0.07, 0.50±0.05, respectively. Compared with the PSF+4-HNE group, the relative expression of pAkt, Nrf2, and HO-1 proteins in the LY294002+4-HNE+PSF group decreased significantly, with significant differences ( t=17.342, 16.813, 18.794; P<0.001). Conclusion:PSF upregulates the expression of HO-1 by activating the phosphatidylinositol 3 kinase/Akt pathway and inhibits cell proliferation, migration, and lumen formation induced by low concentrations of 4-HNE.

【Objective】 Compare the early outcome and safety of endoscopy-unilateral laminectomy for bilateral decompression （Endo-ULBD） and posterior lumbar interbody fusion （PLIF） in the treatment of multi-segment lumbar central spinal stenosis. 【Methods】 We retrospectively analyzed 68 patients with multi-segment central lumbar spinal stenosis treated between October 2019 and October 2020 in the Department of Spine Surgery， Affiliated Hospital of Qingdao University. Of them 33 patients were treated with Endo-ULBD and 35 ones were treated with PLIF. We compared the operation time， times of intraoperative fluoroscopy， estimated intraoperative blood loss， incision length， postoperative time to get out of bed， postoperative hospital duration， complications， visual analogue scale （VAS）， Oswestry dysfunction index （ODI） score before and 1 day， 1 month， and 3 months after operation， Japanese Orthopedic Association Assessment Treatment Score （JOA）， and modified MacNab score 3 months after operation between the two groups of patients. 【Results】 Compared with PLIF group， Endo-ULBD group had significantly shorter operation time， smaller incision length， less intraoperative blood loss， shorter postoperative bed time and postoperative hospital stay， and fewer surgical complications （all P<0.05）. There was significantly more intraoperative fluoroscopy in Endo-ULBD group than in PLIF group （P<0.05）. The VAS， ODI and JOA scores of the two groups were significantly improved after treatment （P<0.05）. There was no statistical difference in VAS of leg pain between the two groups after treatment （P>0.05）. However， after treatment Endo-ULBD group outperformed PLIF group in lower back pain VAS， ODI， JOA and the 3-month follow-up excellent and good rates （P<0.05）. 【Conclusion】 For patients with multi-segment central lumbar spinal stenosis， Endo-ULBD treatment can achieve better early clinical outcome than PLIF surgery， with less bleeding， shorter operation time， faster postoperative recovery， and fewer complications.