Objective:To evaluate the feasibility of using MRI-only simulation images for dose calculation of both photon and proton radiotherapy for nasopharyngeal carcinoma cases.Methods:T 1-weighted MRI images and CT images of 100 patients with nasopharyngeal carcinoma treated with radiotherapy in Cancer Hospital of Chinese Academy of Medical Sciences from January 2020 to December 2021 were retrospectively analyzed. MRI images were converted to generate pseudo-CT images by using deep learning network models. The training set, validation set and test set included 70 cases, 10 cases and 20 cases, respectively. Convolutional neural network (CNN) and cycle-consistent generative adversarial neural network (CycleGAN) were exploited. Quantitative assessment of image quality was conducted by using mean absolute error (MAE) and structural similarity (SSIM), etc. Dose assessment was performed by using 3D-gamma pass rate and dose-volume histogram (DVH). The quality of pseudo-CT images generated was statistically analyzed by Wilcoxon signed-rank test. Results:The MAE of the CNN and CycleGAN was (91.99±19.98) HU and (108.30±20.54) HU, and the SSIM was 0.97±0.01 and 0.96±0.01, respectively. In terms of dosimetry, the accuracy of pseudo-CT for photon dose calculation was higher than that of the proton plan. For CNN, the gamma pass rate (3 mm/3%) of the photon radiotherapy plan was 99.90%±0.13%. For CycleGAN, the value was 99.87%±0.34%. The gamma pass rates of proton radiotherapy plans were 98.65%±0.64% (CNN, 3 mm/3%) and 97.69%±0.86% (CycleGAN, 3 mm/3%). For DVH, the dose calculation accuracy in the photon plan of pseudo-CT was better than that of the proton plan.Conclusions:The deep learning-based model generated accurate pseudo-CT images from MR images. Most dosimetric differences were within clinically acceptable criteria for photon and proton radiotherapy, demonstrating the feasibility of an MRI-only workflow for radiotherapy of nasopharyngeal cancer. However, compared with the raw CT images, the error of the CT value in the nasal cavity of the pseudo-CT images was relatively large and special attention should be paid during clinical application.

Objective: To construct a nonsuicidal selfinjury (NSSI) risk prediction model for middle school students using different machine learning algorithms and evaluate the models effectiveness, so as to provide guidance for the prevention and control of NSSI in campus. Methods: In March 2023, a total of 3 372 middle and high school students from schools in Nanchang, Fuzhou and Shangrao cities in Jiangxi Province were selected by combining stratified random cluster sampling and convenient sampling methods. Questionnaire surveys were conducted using various instruments including general information questionnaire, Selfesteem Scale, Ottawa Selfinjury Scale, Social Support Assessment Scale, Chinese Version of the Olweus Bullying Questionnaire, Event Attribution Style Scale, Adolescent Resilience Scale, and Adolescent Life Events Scale. Data were divided into training set (n=2 361) and test set (n=1 011) at a ratio of 7∶3, and variables were selected based on univariate and LASSO regression results. Four machine learning algorithms including namely random forest, support vector machine, Logistic regression and XGBoost, were used to construct NSSI risk prediction models, and the models performance was evaluated and compared using metrics including area under curve (AUC), sensitivity, specificity, positive predictive value, negative predictive value and F1 score. Results: The detection rate of NSSI among middle school students was 34.4%. Univariate analysis showed that there were statistically significant differences in NSSI detection rates among middle school students of different grades, genders, registered residence locations, whether they were class cadres and four types of bullying (physical, verbal, relational bullying and cyberbullying) (χ2=27.17, 15.81, 11.54, 4.63；68.22, 140.63, 77.81, 13.95, P<0.05). NSSI was included as the dependent variable in the LASSO regression model for variable screening, and the results regression identified 10 predictive variables including grade level, selfesteem, subjective support, support utilization, verbal bullying, emotional control, interpersonal relationships, punishment, loss of relatives and property, and health and adaptation issues. The AUC values of random forest, support vector machine, Logistic regression, and XGBoost algorithms were 0.76, 0.76, 0.76 and 0.77, respectively, with no statistically significant differences between pairwise comparisons (Z=-0.59-0.82, P>0.05). Sensitivity values were 0.62, 0.61, 0.62 and 0.61, respectively. Specificity values were 0.74, 0.78, 0.78 and 0.78, respectively. Positive predictive values were 0.56, 0.59, 0.60 and 0.59, respectively. Negative predictive values were 0.79, 0.79, 0.80 and 0.79, respectively. F1 scores were 0.59, 0.60, 0.61 and 0.60, respectively. Conclusions All four nonsuicidal selfinjury risk prediction models perform well, with the Logistic regression model slightly outperforming the others. Schools and parents should pay attention to the predictive factors corresponding to NSSI, so as to reduce the occurrence of NSSI among middle school students.

Objective To systematically evaluate the accuracy of computer navigation technique in the positioning of bone tunnel location of anterior cruciate ligament reconstruction(ACLR) and its effect on post-operative functional recovery.Methods The controlled trials of computer navigation-assisted ACLR in the da-tabases of Cochrane Library,PubMed,Embase,CNKI,Wanfang and VIP Database were retrieved.The retriev-al time limit was from the establishment of the database to August 2023.According to the inclusion and exclu-sion criteria,the NoteExpress V3.0 software was used to screen the literatures,the Cochrane risk bias assess-ment tool was used to evaluate the quality of the included literatures,and the RevMan5.4 software was used for conducting the meta analysis.Results A total of 10 trials involving 705 patients were included,including 354 cases in the navigation group and 351 cases in the conventional group.The meta analysis results showed that compared with the conventional group,the location positioning of bone tunnel in the navigation group was significantly improved[in femoral side (MD=5.59,95％CI:1.21-9.97,P=0.01) and tibial side (MD=1.32,95％CI:0.20-2.43,P=0.02).However there were no statistically significant differences in the IKDC scores (MD=1.76,95％CI:-0.17 to 3.70,P=0.07),Lysholm scores (MD=0.49,95％CI:-0.16 to 1.14,P=0.14),Tegner scores (MD=-0.08,95％CI:-0.35 to 0.20,P=0.58),KT-1000 anterior shift dis-tance (MD=0.01,95％CI:-0.49 to 0.52,P=0.96),the positive rate of Lachman test (RD=-0.01,95％CI:-0.09 to 0.07,P=0.75) and the positive rate of axial shift test (RD=-0.09,95％CI:-0.22 to 0.04,P=0.20).Conclusion The computer navigation technology is conducive to elevate the accuracy of tibial and femoral tunnel positioning in ACLR,but could not improve the postoperative functional recovery of the pa-tients.

Objective To establish a novel rat model of chronic skeletal muscle composite injury in the lumbar region,to explore its mechanism and treatment method in depth.Methods Twenty-eight SD rats were randomly divided into control group(n = 10),Hitting injury model(HIM)group(n = 9),Composite damage model(CDM)group(n = 9)(vertical blow combined with forced prolonged sitting).Open field test,HE staining and PCR sequencing were performed 3 days after modeling.Results The open field distance of rats in HIM group was significantly shorter than that in the CDM group,and both groups had shorter distances than the control group.HE staining showed multiple muscle fiber breaks,significant widening of muscle gaps,uneven distribution of muscle nuclei,and visible congestion in the model group of simple blow injury;In the CDM group,muscle fibers were ruptured,the muscle gaps were slightly widened,and inflammatory cell infiltration was observed between the muscles,especially around the muscle fiber breakage,with muscle fiber nuclei gathering.A volcano plot of the sequencing result suggested significant differences in the Pf4 gene.GO analysis of muscle tissue in model group rats showed upregulation of oxygen binding and carrier activity pathways.Conclusions This study attempted to establish a composite skeletal muscle injury model to study the pathological changes of chronic skeletal muscle injury in the low back pain and evaluate the efficacy of treatment method.It has practical application value in animal experiments for chronic non-specific low back pain.

Objective:To investigate the correlations between perfused lung volumes, visual scores (using perfusion SPECT/CT) and right-heart catheter (RHC) hemodynamic parameters in patients with chronic thromboembolic pulmonary hypertension (CTEPH).Methods:A total of 51 consecutive CTEPH patients (17 males, 34 females, age (59±12) years) in the First Affiliated Hospital of Guangzhou Medical University between March 2015 and July 2019 were retrospectively analyzed. All patients underwent lung perfusion SPECT/CT imaging and RHC examinations. Perfused lung volumes were determined using threshold-based (15%-85%) segmentation. Visual semiquantitative scoring in each lung segment was performed using Begic method. RHC hemodynamic parameters including pulmonary artery systolic pressure (PASP), pulmonary arterial diastolic pressure (PADP), mean pulmonary artery pressure (mPAP), pulmonary arteriolar wedge pressure (PAWP), pulmonary vessel resistance (PVR), cardiac output (CO), cardiac index (CI) were recorded. Spearman correlation analysis was used to evaluate the correlations between perfused lung volumes, visual scores and hemodynamic parameters.Results:There were significant correlations between perfused lung volumes (30%-70% threshold) and mPAP ( rs values: from -0.414 to -0.302, all P<0.05). Among them, perfused lung volumes under the threshold of 40% and 45% were moderately correlated with mPAP ( rs values: -0.414, -0.412, both P<0.05). Perfused lung volume (40% threshold) was moderately negatively correlated with PASP, PADP ( rs values: -0.402, -0.440, both P<0.05), and slightly negatively correlated with PVR ( rs=-0.352, P<0.05). Visual scores were slightly positively correlated with the PADP ( rs=0.311, P<0.05), while there was no correlation between visual scores and other RHC hemodynamic parameters ( rs values: from -0.201 to 0.275, all P>0.05). Conclusion:Perfused lung volumes based on threshold-based segmentation in lung perfusion SPECT/CT imaging can accurately reflect hemodynamic status and may provide useful information for severity assessment of CTEPH.

Antiporters/genetics* ; Carcinoma, Papillary/pathology* ; Humans ; Neoplasm Metastasis/genetics* ; Sulfate Transporters/genetics* ; Thyroid Cancer, Papillary/pathology* ; Thyroid Neoplasms/pathology*

Objective To investigate the clinical characteristics of DCD donor-derived CRKP infection and bleeding in kidney transplantation,and to summarize the experience of diagnosis,treatment and prevention.Methods A retrospective analysis was carried out from July 2016 to December 2017 in hospital,containing clinical data of 4 cases of CRKP-infected DCD donors and 7 cases of kidney transplantation recipients.Results In the CRKP culture of 4 cases of DCD donors,1 case was positive for blood culture,1 case was positive for urine culture,1 case was positive for sputum culture,and 1 case was negative for blood,urine and sputum culture.The corresponding 7 recipients were all positive for blood culture after renal transplantation,4 cases were positive for urine culture,3 cases were positive for sputum culture,and 5 cases were positive for perirenal drainage.Of the 7 patients,4 cases had renal artery hemorrhage,1 of them was died.The average bleeding time was 17.75 days after operation (14-19 days).In 7 patients with renal transplantation,CRP increasd.And in 3 cases of deaths,CRP was stably higher than normal.Meanwhile,CRP in 4 surviving patients gradually decreased to the normal range after effective anti-infection treatment.All 7 patients were treated with carbapenems;2 patients were dead without avibactam therapy;and 5 cases were treated with avibactam and carbapenems and survived,1 case died and 1 case had good renal function recovery.Conclusion Positive CRKP in blood,urine and sputum of DCD donors can lead to CRKP infection in kidney transplant recipients.Even if the body fluids of donors are all negative,the false negative results could not be excluded.Persistent or increased high-level CRP after operation is an early warning on CRKP infection.And CRP can be used as an indicator for evaluating the effectiveness of anti CRKP therapy.The combination of avibactam and carbapenem antibiotics is an effective regimen in the treatment of DCD donor-derived CRKP.

Objective To observe the alteration and clinical significances of blood coagulation indicators in patients with lymphoplasmacytic lymphoma (LPL). Methods Twenty patients who were newly diagnosed LPL in the First People's Hospital of Changzhou from January 2008 to October 2017 and twenty healthy controls were studied. The patients were treated by chemotherapy, plasma exchange, supplement of coagulation factor or other supportive therapy. The parameters of prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), thrombin time (TT), D-dimer (D-D), and platelet count (Plt) were detected in LPL group and healthy controls. Results The levels of PT and APTT in LPL group were dramatically higher than those in control group [(12.9±1.2) s vs. (11.6±0.9) s, (41.7±9.8) s vs. (24.7±2.9) s], and the level of Plt in LPL group was lower than that in control group [112×109/L (3×109/L - 379×109/L) vs. 210×109/L (170×109/L - 271×109/L)], and the differences were statistically significant (all P< 0.05). There were no significant differences in FIB, TT and D-D levels between LPL group and control group (all P ＞0.05). There were no statistical differences in PT, APTT, FIB, TT, D-D and Plt levels among LPL patients with different types of immunoglobins (all P ＞ 0.05). After treatment, all the coagulation abnormalities got relieved and no patient died of hemorrhage or thrombosis. Conclusions The LPL patients have coagulation disorders and hypercoagulability, and this is independent of the type of immunoglobulin. Clinical attention should be paid to monitoring coagulation indicators to prevent the occurrence of adverse reactions.

Background Retinal Müller cells are important gliocytcs and the source of retinal stem cells.Researching the biological behavior of Müller cells is of important significance to the study on retinal physiopathological process and stem cell therapy of retinal diseases.To establish a stable culture method of Müller cells is a solid basis of relative basic research.Objective This study was to establish a simple and stable method of isolation and culture of human retinal Müller cells and provide sufficient and high-quality Müller cell source.Methods Human retinal Müller cells were isolated from healthy human donor eyes.The mixture solution of hyaluronidase (100 U) and 0.25％ trypsin were used to digest chopped retinal tissue.The DMEM/F12 medium with 20％ fetal bovine serum (FBS) was added to stop the digestion process.RPMI1640 medium with 20％ FBS was used to culture the cell for 72 hours and then replaced the half medium.The cells were passaged by the RPMI1640 medium with 20％ FBS.The morphology of the cells were examied under the optical microscope,and the expressions of glial fibrillary acidic protein (GFAP),a marker of gliocytes,and glutamine synthetase (GS),a special marker of retinal Müller cells,were detected by immunochemistry and immunofluorescence technology.Results Human retinal Müller cells were successfully isolated by enzyme mixture solution of hyaluronidase (100 U) and O.25％ trypsin.The cells were adherent to walls 24 hours after primary culture and completely merged 9-10 days after culture.The cells showed oval in shape with abundant cytoplasm,and a part of cells presented with cone-shaped bulge bilaterally and ectasia in the posterior containing large nuclei.After cells passage,the cells were enlarged and grew toward polygonal shape.The positive expression of GFAP was observed in more than 95％ cells and strongly positive expression of GS was observed in more than 90％ cells by immunohistochemstry and immunofluorescent staining.Conclusions Human retinal Müller cells can be successfully isolated by hyaluronidase combined with trypsin digestion.Abundent and pure human retinal Müller cells can be obtained by successively using RPMI1640 medium with 20％ FBS and 10％ FBS.

Objective To evaluate the diagnostic performance of the histogram analysis of mono-exponential and intravoxel incoherent motion(IVIM) models to the dualistic model of epithelial ovarian cancer(EOC). Methods Forty female patients with histopathologically proven epithelial ovarian cancer underwent preoperative MR examination. Scanning sequences included conventional imaging, diffusion-weighted magnetic resonance imaging with 11 b values (0, 30, 50, 100, 150, 200, 400, 600, 800, 1 000, 1 500 s/mm2) and dynamic contrast enhanced MRI (DCE-MRI). Based on the dualistic model of EOC, all patients were divided into two groups:typeⅠ(low grade, n=16) and typeⅡ(high grade, n=24). ADC, D, D*and f maps and their corresponding histograms were generated by post-processing software. Based on an entire-tumour measurement, the following histogram parameters were recorded, respectively: (a) Mean; (b) the 10th percentile (10th);(c) the mean of the top 10 percent (MeanL);(d) the 90th percentile (90th);(e) the mean of the bottom 10 percent (MeanR). Two types were compared using independent sample t test or Mann-Whitney U test. And areas under ROC curve between two groups were assessed. Results For ADC , D, and f, all indices(Mean,10th,MeanL,90th,MeanR) of the histogram were significantly lower in typeⅡthan in type Ⅰ(P<0.05). All of parameters of D* had no significant different(P>0.05). D demonstrated a comparable accuracy with ADC in differentiating the grade of EOC (area under curve: Mean, 0.898 vs. 0.893; 10th, 0.880 vs. 0.846; MeanL, 0.878 vs. 0.858; 90th, 0.895 vs. 0.839; MeanR, 0.872 vs. 0.814), and both ADC and D have better performance than f. Conclusion It is feasible to stratify the grade of EOC by mono-exponential and IVIM models with histogram metrics,diagnositic efficiency of ADC and D values are higher.