Objective To propose a novel method based on three-dimensional depthwise separable convolution network(3D DSN)for the separation of PET images with dual tracers of 18F-FDG and 18F-FAPI.Methods A total of 120 pairs of 18F-FDG and 18F-FAPI PET images of the same patient scanned separately at different time points were collected,and the dual-tracer PET image was generated through simulation.After the image registration of PET images of two tracers for ensuring spatial position matching,the registered PET images were forward-projected to generate sinogram data,and the sinogram data of two tracers were accumulated to obtain mixed sinogram data.Subsequently,the dual-tracer PET image was reconstructed using maximum likelihood expectation maximization and input into a 3D DSN based network for image separation,thereby obtaining PET images of two single tracers.Results Compared with 3D CNN method,the proposed method increased the structure similarity index measure(SSIM)of the separated 18F-FDG images to the real 18F-FDG images by 0.87%,increased the peak signal-to-noise ratio(PSNR)by 11.8%,and reduced the normalized root mean square error(NRMSE)by 52%.The SSIM of the separated 18F-FAPI images to the real 18F-FAPI images increased by 1.1%,PSNR increased by 17.0%,and NRMSE decreased by 51%.Conclusion The proposed method can be effectively applied to simultaneous PET imaging with dual PET tracers,reducing the number of scans and costs in time and money,and providing clinical doctors more accurate and abundant diagnostic information.

Objectives:Using data from the heart transplant patient dataset of our center,we aimed to develop a preoperative risk scoring model specifically suitable for the Chinese population undergoing heart transplantation.This model was established to predict the likelihood of graft failure within the first year post-surgery and classify recipients according to their risk level.Methods:A retrospective study was conducted at a single center on 1 210 consecutive heart transplant recipients between June 2004 and December 2022.Risk factor screening was performed using univariate and multivariate logistic regression analyses.Variable selection was carried out through a stepwise backward procedure based on the Akaike Information Criterion(AIC).The regression coefficients obtained from the final model were employed as weighting factors in the multifactor analysis.The study utilized the area under the receiver operating characteristic(ROC)area under curve(AUC)as a metric to evaluate the performance of the model.Patients were stratified into low,medium,and high-risk groups based on the distribution of the calculated scores.Survival analysis was conducted on the various risk groups using the Kaplan-Meier method,with statistical comparisons performed using the log-rank test.A significance level of P<0.05 was deemed statistically significant.Results:A risk scoring model,denoted as the heart transplant(HTx)score,was developed,comprising 11 variables and yielding a total score of 20.6 points.In comparison to the low-risk group,the OR for 1-year graft failure in the medium-risk group was 2.0(95%CI:1.1-3.6,P=0.02),while the high-risk group had an OR of 9.8(95%CI:5.4-17.7,P<0.01).The risk scoring model exhibited strong discriminative ability with an AUC of 0.712(95%CI:0.646-0.778)and an internally validated bias-corrected AUC of 0.713.The results of the Hosmer-Lemeshow goodness-of-fit test indicated that the predictive model demonstrated a strong calibration ability(Hosmer-Lemeshow χ2=2.92,P=0.71).Within the cohort,the AUC values for the IMPACT score,UNOS score,RSS score,Mayo score,BO score,and TRS score models were 0.645,0.651,0.632,0.589,0.610,and 0.604,respectively.These findings suggest that the HTx scoring model exhibited superior predictive performance compared to the aforementioned models in forecasting outcomes within our cohort.The Kaplan-Meier survival analysis revealed statistically significant differences in long-term survival rates between the three risk groups,a noticeable decrease in long-term survival rates were observed with increasing levels of HTx risk stratification(P<0.05).Conclusions:Present results indicate a significant association between the developed HTx risk scores and graft failure within the initial year post-surgery,present model effectively categorizes the heart transplant recipients into low,medium,and high-risk groups and is valuable for risk stratification.

Objective To establish a research protocol to clarify the characteristic changes in major functional activities and cellular processes involved in bone marrow during aging using RNA sequencing,and to identify potential targets for aging prediction and intervention.Methods Bone marrow cells were extracted from the bilateral tibiae and femurs of three C57BL/6J male mice aged 2,10,and 18 months,respectively.After red blood cell lysis,RNA was extracted for sequencing analysis.Results The result of gene expression and Venn analysis showed that gene expression levels were predominantly down-regulated from 2～10 months,but mainly up-regulated from 10～18 months.Gene expression thus changed from mainly down-regulation to mainly up-regulation during maturation and development in mice.Kyoto encyclopedia of genes and genomes and gene set enrichment analyses indicated that bone marrow tissues in mice at different ages showed significant expression differences in the"immune system""development and regeneration""transport and catabolism""cell growth and death"and other pathways.Specifically,inflammatory,cytoskeletal,and DNA repair pathways showed sustained activation,contrasting with progressive hematopoietic decline and fluctuating immune regulation.Enriched pathway screening revealed interactions among differentially expressed genes,such us upregulated genes Bmpr1a and Inhba,downregulated genes Dntt and Ccnd1,and downregulated genes Col1a1,Col1a2,Fcgr1,Fyn,Lgmn,Ctsl,Ctsk,Ctss,Gnail,Myl4,and Ccr5,involved in HSCs homeostasis,cell cycle,DNA repair,immune regulation,and apoptosis.Conclusions This study provides data on gene expression changes at the transcriptional level and offers a research strategy to explore the major characteristic changes in bone marrow during aging in mice.The result identify aging-related genes and signaling pathways,thus providing new strategies for delaying aging and preventing aging-related diseases.

Objective To propose a novel method based on three-dimensional depthwise separable convolution network(3D DSN)for the separation of PET images with dual tracers of 18F-FDG and 18F-FAPI.Methods A total of 120 pairs of 18F-FDG and 18F-FAPI PET images of the same patient scanned separately at different time points were collected,and the dual-tracer PET image was generated through simulation.After the image registration of PET images of two tracers for ensuring spatial position matching,the registered PET images were forward-projected to generate sinogram data,and the sinogram data of two tracers were accumulated to obtain mixed sinogram data.Subsequently,the dual-tracer PET image was reconstructed using maximum likelihood expectation maximization and input into a 3D DSN based network for image separation,thereby obtaining PET images of two single tracers.Results Compared with 3D CNN method,the proposed method increased the structure similarity index measure(SSIM)of the separated 18F-FDG images to the real 18F-FDG images by 0.87%,increased the peak signal-to-noise ratio(PSNR)by 11.8%,and reduced the normalized root mean square error(NRMSE)by 52%.The SSIM of the separated 18F-FAPI images to the real 18F-FAPI images increased by 1.1%,PSNR increased by 17.0%,and NRMSE decreased by 51%.Conclusion The proposed method can be effectively applied to simultaneous PET imaging with dual PET tracers,reducing the number of scans and costs in time and money,and providing clinical doctors more accurate and abundant diagnostic information.

Objective To establish a research protocol to clarify the characteristic changes in major functional activities and cellular processes involved in bone marrow during aging using RNA sequencing,and to identify potential targets for aging prediction and intervention.Methods Bone marrow cells were extracted from the bilateral tibiae and femurs of three C57BL/6J male mice aged 2,10,and 18 months,respectively.After red blood cell lysis,RNA was extracted for sequencing analysis.Results The result of gene expression and Venn analysis showed that gene expression levels were predominantly down-regulated from 2～10 months,but mainly up-regulated from 10～18 months.Gene expression thus changed from mainly down-regulation to mainly up-regulation during maturation and development in mice.Kyoto encyclopedia of genes and genomes and gene set enrichment analyses indicated that bone marrow tissues in mice at different ages showed significant expression differences in the"immune system""development and regeneration""transport and catabolism""cell growth and death"and other pathways.Specifically,inflammatory,cytoskeletal,and DNA repair pathways showed sustained activation,contrasting with progressive hematopoietic decline and fluctuating immune regulation.Enriched pathway screening revealed interactions among differentially expressed genes,such us upregulated genes Bmpr1a and Inhba,downregulated genes Dntt and Ccnd1,and downregulated genes Col1a1,Col1a2,Fcgr1,Fyn,Lgmn,Ctsl,Ctsk,Ctss,Gnail,Myl4,and Ccr5,involved in HSCs homeostasis,cell cycle,DNA repair,immune regulation,and apoptosis.Conclusions This study provides data on gene expression changes at the transcriptional level and offers a research strategy to explore the major characteristic changes in bone marrow during aging in mice.The result identify aging-related genes and signaling pathways,thus providing new strategies for delaying aging and preventing aging-related diseases.

Objectives:Using data from the heart transplant patient dataset of our center,we aimed to develop a preoperative risk scoring model specifically suitable for the Chinese population undergoing heart transplantation.This model was established to predict the likelihood of graft failure within the first year post-surgery and classify recipients according to their risk level.Methods:A retrospective study was conducted at a single center on 1 210 consecutive heart transplant recipients between June 2004 and December 2022.Risk factor screening was performed using univariate and multivariate logistic regression analyses.Variable selection was carried out through a stepwise backward procedure based on the Akaike Information Criterion(AIC).The regression coefficients obtained from the final model were employed as weighting factors in the multifactor analysis.The study utilized the area under the receiver operating characteristic(ROC)area under curve(AUC)as a metric to evaluate the performance of the model.Patients were stratified into low,medium,and high-risk groups based on the distribution of the calculated scores.Survival analysis was conducted on the various risk groups using the Kaplan-Meier method,with statistical comparisons performed using the log-rank test.A significance level of P<0.05 was deemed statistically significant.Results:A risk scoring model,denoted as the heart transplant(HTx)score,was developed,comprising 11 variables and yielding a total score of 20.6 points.In comparison to the low-risk group,the OR for 1-year graft failure in the medium-risk group was 2.0(95%CI:1.1-3.6,P=0.02),while the high-risk group had an OR of 9.8(95%CI:5.4-17.7,P<0.01).The risk scoring model exhibited strong discriminative ability with an AUC of 0.712(95%CI:0.646-0.778)and an internally validated bias-corrected AUC of 0.713.The results of the Hosmer-Lemeshow goodness-of-fit test indicated that the predictive model demonstrated a strong calibration ability(Hosmer-Lemeshow χ2=2.92,P=0.71).Within the cohort,the AUC values for the IMPACT score,UNOS score,RSS score,Mayo score,BO score,and TRS score models were 0.645,0.651,0.632,0.589,0.610,and 0.604,respectively.These findings suggest that the HTx scoring model exhibited superior predictive performance compared to the aforementioned models in forecasting outcomes within our cohort.The Kaplan-Meier survival analysis revealed statistically significant differences in long-term survival rates between the three risk groups,a noticeable decrease in long-term survival rates were observed with increasing levels of HTx risk stratification(P<0.05).Conclusions:Present results indicate a significant association between the developed HTx risk scores and graft failure within the initial year post-surgery,present model effectively categorizes the heart transplant recipients into low,medium,and high-risk groups and is valuable for risk stratification.

Objective To establish interferon-induced transmembrane protein 3(Ifitm3)knockout mice and to explore the effects of Ifitm3 on the proliferation and differentiation of adult neural stem cells of mice(aNSCs).Methods IFITM3 knockout mice were established by the CRISPR/Cas9 method and identified by genotype identification and Western Blot.The differences between Ifitm3-knockout mice and wild-type mice were analyzed by hematoxylin-eosin(HE)staining and flow cytometry.The aNSCs of wild-type mice and Ifitm3-knockout mice were isolated and cultured,the number and size of neurospheres were detected,The ability of aNSCs to proliferate and differentiate were detected by quantitative reverse-transcription polymerase chain reaction,Western Blot,and immunofluorescence.Results Ifitm3-knockout mice were successfully established.The mice developed normally,and there were no obvious abnormalities either histopathologically or the immune system.In vitro experiments showed that Ifitm3 knockout inhibited the self-renewal potential of aNSCs,led to a decrease in the proliferation ability of aNSCs,and inhibited the differentiation of aNSCs into immature neurons and astrocytes.Conclusions This study finds that a lack of IFITM3 result in the ability of aNSCs to proliferate and differentiate decreased,IFITM3 may regulate the function of aNSCs.

Heart failure represents a significant public health challenge in China at present.The technology development of left ventricular assist device has become a therapy option for end-stage heart failure patients.The third generation left ventricular assist device has undergone significant improvements in its principle,structure,size,mechanical stability,biocompatibility,and many other aspects.In recent years,multiple products have been put into clinical application,meeting the need of heart failure patients with implantation indications.This article mainly reviews the technological development,clinical application,available domestic and abroad products,and future prospects of the third generation domestic left ventricular assist device.

Objective To evaluate the effect of extracorporeal membrane oxygenation (ECMO) on early allograft dysfunction (EAD) after heart transplantation. Methods Clinical data of 614 heart transplant recipients were retrospectively analyzed. All recipients were divided into the ECMO group (n=43) and non-ECMO group (n=571) according to postoperative application of ECMO. In the ECMO group, the conditions of recipients undergoing ECMO after heart transplantation were summarized. Perioperative status and long-term prognosis of recipients were compared between two groups. Results Among 43 recipients undergoing ECMO, 17 cases underwent thoracotomy due to bleeding, 10 cases of infection, 4 cases of venous thrombosis of the lower limbs, and 1 case of stroke, respectively. Twenty-six recipients were recovered and discharged after successful weaning from ECMO, six died during ECMO support, six died after weaning from ECMO, five received retransplantation due to unsuccessful weaning from ECMO, and only one survived after retransplantation. Compared with the non-ECMO group, intraoperative cardiopulmonary bypass duration was significantly longer, the proportion of recipients requiring postoperative intra-aortic balloon pump (IABP), dialysis due to renal insufficiency, reoperation for hemostasis, infection, mechanical ventilation time≥96 h and tracheotomy was significantly higher, and the length of postoperative intensive care unit (ICU) stay was significantly longer in the ECMO group (all P < 0.05). The survival rate after discharge and 90-d survival rate in the ECMO group were 63% and 96%, significantly lower than 97% and 100% in the non-ECMO group (both P < 0.05). Survival analysis showed that the long-term survival rate in the ECMO group was significantly lower than that in the non-ECMO group (P < 0.05). After excluding the recipients who died within 90 d after heart transplantation, no significant difference was observed in the long-term survival rate (P > 0.05). Conclusions ECMO is an effective treatment of EAD after heart transplantation. The short-term survival rate of recipients using ECMO after heart transplantation is lower than that of those who do not use ECMO, and there is no significant difference in long-term survival of recipients surviving 90 d after heart transplantation.

Objective To analyze the early outcomes of heart transplantation in critical patients and its significance in donor allocation decision. Methods Clinical data of 449 recipients undergoing heart transplantation were retrospectively analyzed. According to preoperative status, all patients were divided into the critical status group (n=64) and general status group (n=385). The incidence of critical status was summarized. Clinical data of recipients were statistically compared between two groups. Postoperative survival and causes of death in recipients between two groups were analyzed. Perioperative results of critical recipients undergoing different mechanical circulation support as a bridge to heart transplantation were compared. Results Critical patients accounted for 14.3% of the total number of transplant recipients. The proportion of critical patients gradually increased in recent 5 years. Compared with the general status group, the recipients in critical status group had a lower proportion of smoking history, a higher proportion of cardiac surgery history, a higher serum level of creatinine, and a higher proportion of primary diseases of heart failure before heart transplantation(all P≤0.01). The proportion of undergoing mechanical circulation support was higher, the incidence of complications was higher, the stay time in intensive care unit (ICU) was longer and the in-hospital fatality was higher after heart transplantation in the critical status group (all P≤0.01). The 1-year survival rate of recipients in critical status group was significantly lower than that in general status group (83% vs. 95%, P < 0.01). The fatality of recipients due to infection and multiple organ failure in critical status group was higher than that in general status group. Among 64 critical recipients, 1 recipient received ventilator alone, and 63 recipients underwent mechanical circulation support devices as a bridge to heart transplantation. Among them, intra-aortic balloon pump (IABP) alone was applied in 49 cases (77%), 8 cases (13%) of extracorporeal membrane oxygenation (ECMO) combined with IABP, 4 cases (6%) of ECMO alone, and 2 cases (3%) of left ventricular assist device (LVAD) alone. Critical patients who received preoperative ECMO and ECMO combined with IABP bridging to heart transplantation have a higher proportion of postoperative complications, a longer ICU stay time, a longer mechanical ventilation time, and a higher proportion of hospital deaths. Conclusions The overall prognosis of critical patients undergoing heart transplantation is relatively poor. Effective preoperative management may reverse the high-risk status of critical patients in a certain extent. The limited quantity of donor heart should be allocated to the most urgent patients who can obtain the greatest benefit from heart transplantation.