OBJECTIVE: To investigate the influence of different scanning conditions on the image quality of medical electron accelerator cone-beam computed tomography (CBCT) and provide a reference for the selection of scanning conditions for different body parts. Methods Set different scanning conditions, the Catphan 503 phantom was scanned using CBCT parameters to analyze the influence of spatial resolution, noise, uniformity, spatial geometric accuracy, and low-contrast resolution on the image quality of CBCT. RESULTS: For the head, chest, and abdomen, with the increase in scanning parameter values, the noise value decreased by 47.4%, 26.1%, and 51.3% respectively, and the uniformity values decreased by 30.2%, 26.6%, and 47.9% respectively. The low-contrast resolution values decreased by 50.6%, 34.2%, and 12.0%. The influence of different scanning conditions on spatial geometric accuracy and spatial resolution is not significant. CONCLUSION Different scanning parameters have a certain influence on the image quality of medical electron accelerator CBCT. Lower scanning parameters can be selected based on individual patients to reduce the additional radiation dose, providing a reference for the safe application of CBCT image guidance in radiotherapy.
Cone-Beam Computed Tomography/instrumentation* ; Phantoms, Imaging ; Particle Accelerators

Objective: To investigate the association between edentulism and the risk of social isolation in middle-aged and elderly populations, provide empirical evidence for formulating social isolation prevention and intervention policies targeting edentulous middle-aged and elderly populations. Methods: Data were derived from the baseline survey (2011) and three follow-ups (2013, 2015, 2018) of the China Health and Retirement Longitudinal Study (CHARLS). Participants were enrolled in the follow-up from the baseline. Those identified as socially isolated in any of the follow-up surveys conducted in 2013, 2015, or 2018 were considered to have reached the endpoint; otherwise, the follow-up was continued until the end of the 2018 survey; 9 870 individuals were ultimately included. Subjects were grouped by edentulism status. Chi-square test and multivariate Cox regression analysis were performed using Stata 17.0. Results: During a median follow-up of 6.54 years, 1 800 cases of social isolation occurred, with an incidence rate of 18.23%（17.47%~18.99%）. Multivariate Cox regression showed that edentulism was associated with an increased risk of social isolation (HR=1.21, 95% CI: 1.03-1.42) after adjusting for confounders. Subgroup analysis revealed population heterogeneity. Sensitivity analyses confirmed the stability of the results. Conclusion Edentulism is associated with an increased risk of social isolation in middle-aged and elderly adults.

Objective:To assess the effects of the scanning parameters of cone beam computed tomography(CBCT)on image quality,positioning error and additional radiation dose for patients with cervical cancer after tube voltage was reduced,so as to explore scanning conditions that was suitable to patients with cervical cancer.Methods:Seventy-two patients with cervical cancer who received radiotherapy in Deyang People's Hospital from January 2020 to August 2022 were selected.According to different scanning parameters,they were divided into low-dose group A(120 kV,154.4 mAs),low-dose group B(120 kV,228.8 mAs)and conventional group[adopted business-supplied scan sequences(120 kV,675.8 mAs)].The CBCT scan image was obtained by decreasing the tube voltage and tube current,and reducing scanning angle.The registration results of positioning error of low-dose group A,B and conventional group on three directions included left and right(x-axis),head and foot(y-axis)and abdominal and back(z-axis)were respectively obtained,and the results were analyzed by variance analysis.The Catphan503 phantom of X-ray volumetric imaging(XVI)was used to measure the image quality of the corresponding 3 groups,and the further comparison was conducted.Results:There were no significant differences between the three groups in the scanning parameters on x,y and z axis directions for positioning error of patients with cervical cancer(P＞0.05).The scanning times of low-dose group A and B were approximately 1 minute,and the scanning time of conventional group was approximately 2 minutes.The noises of low-dose group A and B,and conventional group were respectively 36.51％,26.09％and 18.37％,and the radiation dose that was generated by CBCT image scanning in group A was correspondingly reduced.Conclusion:The reductions of scanning speed and collimator size of CBCT scanning parameters do not affect the positioning error and image quality,and it can decrease the scanning time and additional radiation dose of patients in undergoing radiotherapy.

【Objective】 To explore the application value of different language assessment tools in the assessment of language development of 12-month-old high-risk infants, and to screen out simple and valid language assessment tools. 【Methods】 A total of 217 11- to 13-month-old high-risk infants who were followed up at the outpatient service for high-risk infants at the child health clinic of Guiyang Maternal and Child Health Hospital from March 2022 to May 2023 were selected as the study subjects. Their language was evaluated by Early Language Milestone Scale (ELMS), Putonghua Communicative Development Inventory (PCDI) and Ages and Stages Questionnaire-Third Edition (ASQ-3). With Gesell as the gold standard for the assessment of language, the area under receiver operating characteristic curve (AUC), sensitivity, specificity, accuracy, positive predictive value, negative predictive value, Youden index and Kappa value of the three tools were calculated. Spearman correlation analysis was used to analyze the correlation between the different language assessment scales. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used to evaluate the three tools. 【Results】 1)Among 217 high-risk infants, 78 preterm infants was the most (35.94%). The rate of delayed language development detected by Gesell, ELMS, PCDI-comprehension, PCDI-expression, ASQ-3 were 5.5%, 7.8%, 36.4%, 30.0% and 11.5%, respectively. 2)ASQ-3 had the strongest correlation with Gesell language region (rs=0.607, P<0.01) and it had the most AUC (AUC=0.812, P<0.05). The consistency between ASQ-3 and Gesell was moderate (Kappa=0.56, P<0.01). ASQ-3 had the highest sensitivity(91.7%), accuracy(93.1%), negative predictive value(99.5%) and Youden index(0.85), and ELMS had the highest specificity(94.6%). 3) Comprehensive evaluation of three tools by the TOPSIS indicated that ASQ-3 was the best, followed by ELMS and PCDI-comprehension was the worse. 【Conclusion】 Among the three assessment tools, ASQ-3 has the highest value in assessing the language development of 11- to 13-month-old high risk infants, and it may be necessary to expand the age range and establish a national norm of ELMS and PCDI in the future.

Objective:To investigate the stability of α-synuclein (α-Syn) aggregates formed by incubation with blood plasma of patients with Parkinson's disease (PD).Methods:Peripheral blood samples were collected from 10 patients diagnosed as having PD in our hospital from June 2020 to December 2020 and 10 healthy control subjects (HC) at the same time period. The 1 mg recombinant human α-Syn was dissolved in 140 μL 0.01 mol/L phosphate buffer solution (PBS), and then, incubated with plasma from HC and PD patients and PBS at 37 ℃ for 7 d (HC group, PD group and PBS group). Preformed fiber (PFF) group was used for subsequent experiment with 10 μg PFF. After digestion with different concentrations of trypsin (concentration ratios of trypsin/α-Syn=1:80, 1:40, and 1:20) and protease K (PK, 1.0, 1.5, and 2.0 μg/mL), the differences of α-Syn levels before and after digestion were detected by Western blotting.Results:(1) Effect of trypsin on PFF digestion: PFF gradually decreased with the increase of trypsin doses; when trypsin/α-Syn ratio=1:20, α-Syn aggregates with molecular weight greater than 35 000 were almost completely digested, and its digestion was significantly different as compared with that in other concentration ratios ( P<0.05). (2) Effect of trypsin on digestion of α-Syn aggregates: at the relative molecular weight<25 000, when the concentration ratio of trypsin/α-Syn=1:20, as compared with HC and PD groups, the PBS group had significantly more obvious decrease ( P<0.05). At the relative molecular weight 35 000-40 000, the α-Syn levels in PBS, HC and PD groups were significantly decreased as compared with those before digestion at all concentration ratios; as compared with HC and PD groups, the PBS group had significantly more obvious decrease ( P<0.05). At molecular weight>40 000, α-Syn decreased significantly in PD group only when the concentration ratio of trypsin/α-Syn=1:20, and the degrees of digestion was PBS group>HC group>PD group, with significant differences among groups ( P<0.05). (3) Effect of PK on PFF digestion: when PK concentration was 1.0, 1.5 or 2.0 μg/mL, α-Syn was basically digested at relative molecular weight>35 000, and α-Syn monomer was reduced and small fragment appeared at relative molecular weight<25 000; as compared with negative controls (0 μg/mL PK), these changes in groups of PK concentration of 1.0, 1.5 or 2.0 μg/mL were significantly different ( P<0.05). (4) Effect of PK on digestion of α-Syn aggregates: at relative molecular weight<25 000, α-Syn in PBS group was digested into smaller fragments while α-Syn in HC and PD groups was not digested; significant differences was noted among groups at the same concentration ( P<0.05). At relative molecular weight of 35 000-40 000, with the increase of PK concentration, the amount of α-Syn dimer in PBS group decreased (increased digestibility), that in HC group increased, however, that in PD group did not change obviously; significant difference was noted at the same concentration among the three groups ( P<0.05). At relative molecular weight>40 000, with the increase of PK concentration, α-Syn in PBS, HC and PD groups decreased to a certain extent, and significant difference was noted among groups at the same concentration ( P<0.05). Conclusion:The stability of α-Syn aggregates formed by incubation with plasma from PD patients is higher than that formed by incubation with HC plasma and PBS.

Objective To summarize the etiology,diagnosis and treatment of three cases of duodenal perforation. Methods The data of 3 cases of children with duodenal perforation in our hospital from September 14,2016 to June 20,2017 were retrospectively analyzed. The causes,clinical features and treatment of children's duodenal perforation were summarized. Results A total of 2 males and 1 females aged 2 years,3 years and 5 years were included in the 3 cases. All 3 cases had fever history of upper respiratory tract infection before onset. Acute abdominal pain occurred after oral administration of ibuprofen several times,and all the abdominal plain films prompted pneumoperitoneum. Three cases of perforation sites were duodenal anterior wall,diameter were 0. 5-1 cm. Two cases of small amount of pneumoperitoneum were explored and repaired the duodenal perforation by 3D laparoscopic,1 case underwent laparotomy to repair the duodenal perforation due to a large number of liquid pneumoperitoneum and severe shock. Repair of 3 cases were covered with omentum. Three cases were all cured without anastomotic fistula, ulcer, adhesive intestinal obstruction or other complications. Followed-up in the department of gastroenterology,3 cases had no Helico-bacter pylori infection. Conclusion Repeatedly oral administration of ibuprofen can cause duodenal perfora-tion in children in the short term. Once the digestive tract perforation confirmed,emergency surgical explora-tion is needed. Laparoscopic repair of duodenum perforation is safe and effective and may have a faster recov-ery. We can choose exploratory laparotomy if conditions are not allowed.

AIM:To investigate the expression and potential role of complement 5a receptor (C5aR) in chro-nic graft-versus-host disease (cGVHD).METHODS:The expression of C5aR on lymphocytes and the frequency of CD4+CD25+ Foxp3+ regulatory T cells (Tregs) in 20 cGVHD patients and 9 healthy donors was detected by flow cytometry.The correlation between the expression of C5aR and the percentage of Tregs in the cGVHD patients was analyzed.In addition, the splenocytes from the mice were cultured in vitro, and stimulated these splenocytes with recombinant mouse C5a protein (rmC5a).The peripheral blood mononuclear cells (PBMCs) from cGVHD patients were cultured in vitro, which was inhibited by C5aR antagonist (C5aRA).The frequency of Tregs in these splenocytes and the PBMCs were evaluated by flow cytometry.RESULTS:The expression of C5aR on the lymphocytes was significantly increased in the cGVHD patients compared with the healthy donors, while the percentage of Tregs was markedly lower in the cGVHD patients.The expression of C5aR was negatively correlated with the percentage of Tregs.Furthermore, the development of Tregs was suppressed by rmC5a stimulation, but was promoted by C5aRA in vitro.CONCLUSION:C5aR elevation is associated with Treg reduction in cGVHD, indicating that C5aR may play a potential role in suppressing Tregs, resulting in the incidence of cGVHD.

Objective:To construct I-Ad/IgG2b Fc baculovirus expression vector and express I-Ad/IgG2b Fc dimer fusion protein in Sf9 insect cells.Methods:I-Ad α,I-Ad β and IgG2b Fc gene sequences were amplified from BALB/c mouse lymphocytes by RT-PCR.I-Ad α and I-Ad β were connected with the leucine zipper sequence Fos and Jun respectively by overlapping PCR to form I-Ad α-Fos and I-Ad β-Jun.I-Ad α-Fos and IgG2b Fc fragments were ligated by restriction sites Xba I to form I-Ad α-Fos-IgG2b Fc recombination sequence.I-Ad α-Fos-IgG2b Fc and I-Ad β-Jun fragments were inserted to PPH and PP10,which were the downstream of the promoters in the plasmid pFastBacTMDual,to form pFastBacTMDual+[I-Ad/IgG2b Fc] recombinant plasmids.The constructed vector was identified by PCR,restriction endonuclease and sequencing.The recombinant plasmids pFastBacTMDual+[I-Ad/IgG2b Fc] was transferred into the DH10Bac competent cell to form recombinant baculovirus Bacmid+[I-Ad/IgG2b Fc].The recombinant baculovirus was transfected into Sf9 insect cells by liposome transfection reagent.After infected with Sf9 insect cells,the supernatant was collected and concentrated by PEG20000 to obtain I-Ad/IgG2b Fc dimer fusion protein.The fusion protein was detected by double-antibody sandwich ELISA and Western blot.Results:PCR,restriction enzyme digestion and sequencing confirmed that the recombinant vector pFastBacTMDual+[I-Ad/IgG2b Fc] had the correct sequence.The double antibody sandwich ELISA and Western blot showed that recombinant bacmid could successfully infect Sf9 insect cells,and the expressed fusion protein had the correct conformation.Conclusion:The pFastBacTMDual+[I-Ad/IgG2b Fc] baculovirus expression vector was successfully constructed and expressed in Sf9 insect cells,laying a foundation for the study of I-Ad-restricted T cells.

Objective: To investigate the clinical effect and safety of long-acting pegylated interferon-α-2b (Peg-IFN-α-2b) (Y shape, 40 kD) injection (180 μg/week) in the treatment of HBeAg-positive chronic hepatitis B (CHB) patients, with standard-dose Peg-IFN-α-2a as positive control. Methods: This study was a multicenter, randomized, open-label, and positive-controlled phase III clinical trial. Eligible HBeAg-positive CHB patients were screened out and randomized to Peg-IFN-α-2b (Y shape, 40 kD) trial group and Peg-IFN-α-2a control group at a ratio of 2:1. The course of treatment was 48 weeks and the patients were followed up for 24 weeks after drug withdrawal. Plasma samples were collected at screening, baseline, and 12, 24, 36, 48, 60, and 72 weeks for centralized detection. COBAS® Ampliprep/COBAS® TaqMan® HBV Test was used to measure HBV DNA level by quantitative real-time PCR. Electrochemiluminescence immunoassay with Elecsys kit was used to measure HBV markers (HBsAg, anti-HBs, HBeAg, anti-HBe). Adverse events were recorded in detail. The primary outcome measure was HBeAg seroconversion rate after the 24-week follow-up, and non-inferiority was also tested. The difference in HBeAg seroconversion rate after treatment between the trial group and the control group and two-sided confidence interval (CI) were calculated, and non-inferiority was demonstrated if the lower limit of 95% CI was > -10%. The t-test, chi-square test, or rank sum test was used according to the types and features of data. Results: A total of 855 HBeAg-positive CHB patients were enrolled and 820 of them received treatment (538 in the trial group and 282 in the control group). The data of the full analysis set showed that HBeAg seroconversion rate at week 72 was 27.32% in the trial group and 22.70% in the control group with a rate difference of 4.63% (95% CI -1.54% to 10.80%, P = 0.1493). The data of the per-protocol set showed that HBeAg seroconversion rate at week 72 was 30.75% in the trial group and 27.14% in the control group with a rate difference of 3.61% (95% CI -3.87% to 11.09%, P = 0.3436). 95% CI met the non-inferiority criteria, and the trial group was non-inferior to the control group. The two groups had similar incidence rates of adverse events, serious adverse events, and common adverse events. Conclusion In Peg-IFN-α regimen for HBeAg-positive CHB patients, the new drug Peg-IFN-α-2b (Y shape, 40 kD) has comparable effect and safety to the control drug Peg-IFN-α-2a.

Objective: To investigate the efficacy and safety of the new investigational drug pegylated interferon α-2b (Peg-IFN-α-2b) (Y shape, 40 kD) injection (180 µg/week) combined with ribavirin in the treatment of patients with genotype 1/6 chronic hepatitis C (CHC), with standard-dose Peg-IFN-α-2a combined with ribavirin as a positive control. Methods: A multicenter, randomized, open-label, and positive-controlled phase III clinical trial was performed. Eligible patients with genotype 1/6 CHC were screened out and randomly divided into Peg-IFN-α-2b(Y shape, 40kD) group and Peg-IFN-α-2a group at a ratio of 2:1. The patients in both groups were given oral ribavirin for 48 weeks in addition and then followed up for 24 weeks after drug withdrawal. Abbott Real Time HCV Genotype II was used to determine HCV genotype, and Cobas TaqMan quantitative real-time PCR was used to measure HCV RNA level at 0, 4, 12, 24, 48, and 72 weeks. Adverse events were recorded in detail. The primary efficacy endpoint was sustained virological response (SVR), and a non-inferiority test was also performed. Results: A total of 561 patients with genotype 1/6 CHC were enrolled, among whom 529 received treatment; 90.9% of these patients had genotype 1 CHC. The data of the full analysis set showed that SVR rate was 69.80% (95% CI 65.00%-74.60%) in the trial group and 74.16% (95% CI 67.73%-80.59%) in the control group (P = 0.297 0). The data of the per protocol set (PPS) showed that SVR rate was 80.63% (95% CI 76.04%-85.23%) in the trial group and 81.33% (95% CI 75.10%-87.57%) in the control group (P = 0.849 8), and the 95% CI of rate difference conformed to the non-inferiority standard. The analysis of the PPS population showed that of all subjects, 47.9% achieved rapid virologic response, with a positive predictive value of 93.8%. The incidence rate of adverse events was 96.30% in the trial group and 94.94% in the control group, and the incidence rate of serious adverse events was 5.13% in the trail group and 5.06% in the control group. Conclusion In the regimen of Peg-IFN-α combined with ribavirin for the treatment of genotype 1/6 CHC, the new investigational drug Peg-IFN-α-2b(Y shape, 40 kD) has comparable clinical effect and safety to the control drug Peg-IFN-α-2a.