Objective:To improve the quality assurance (QA) skills of radiotherapy personnel and medical students and reduce the radiation risk of training by developing a remote training system for QA of medical electronic linear accelerators.Methods:This training system was built based on radiotherapy technology and quality control contents of medical electronic linear accelerators, and a virtual reality interactive software was developed using extended reality (XR) technology Unity 3D. A remote control module of multi-terminal platform was also developed. A multi-perspective evaluation system was adopted and a questionnaire was designed to analyze the application value of this system.Results:The training system reproduced the live environment and physical objects of medical electronic linear accelerator treatment room. It built a multi-terminal virtual simulation training system with radiotherapy technology as well as QA knowledge system. This system could provide 5G remote control of medical electronic linear accelerator for off-site quality control demonstration and guidance. By March 1, 2022, a total number of 133 people had been trained using this system, 76 valid questionnaires had been taken, of which 90.79% (69/76) of the respondents trusted the experimental results shown by the system and 88.16% (67/76) of the respondents considered the training system necessary.Conclusions:The training effect of this system is widely recognized. It fundamentally reduces the training radiation hazard and provides reference for the reform and progress of QA training mode of medical electronic linear accelerators.

ObjectiveTo investigate the mechanism of icariin in ameliorating efferocytosis dysfunction and inflammatory response of alveolar macrophages induced by cigarette smoke extract via the peroxisome proliferator-activated receptor gamma （PPARγ） signaling pathway. MethodThe untreated rat alveolar macrophages （NR8383） were taken as the blank group. The NR8383 cells treated with 10% cigarette smoke extract were divided into model， low-， medium-， and high-dose （10， 20， 40 μmol·L^-1） icariin， PPARγ inhibitor， and PPARγ inhibitor + low-， medium-， and high-dose icariin groups. Alamar blue colorimetry was employed to examine the proliferation and toxicity of icariin on NR8383 cells. The efferocytosis rate of NR8383 cells was detected by flow cytometry. Enzyme-linked immunosorbent assay was employed to measure the levels of tumor necrosis factor-alpha （TNF-α）， transforming growth factor-β₁ （TGF-β₁）， and milk fat globule-epidermal growth factor 8 （MFG-E8）. Western blot and Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） were employed to determine the protein and mRNA levels， respectively， of PPARγ， CD36， and RAS-related C3 botulinum toxin substrate 1 （Rac1）. ResultThe efferocytosis dysfunction model of NR8383 was established with the cigarette smoke extract. Compared with the blank control group， the model group showed decreased efferocytosis rate （P<0.05）， elevated TNF-α level （P<0.05）， lowered TGF-β₁ and MFG-E8 levels （P<0.01）， and down-regulated mRNA and protein levels of PPARγ， CD36， and Rac1 （P<0.05， P<0.01）. Compared with the model group， the treatment with icariin increased the efferocytosis rate （P<0.05， P<0.01）， lowered the TNF-α level （P<0.01）， elevated TGF-β₁ and MFG-E8 levels （P<0.05）， and up-regulated the protein and mRNA levels of PPARγ， CD36， and Rac1 （P<0.05， P<0.01）. Compared with icariin alone， PPARγ inhibitor + icariin decreased the efferocytosis rate （P<0.05） and down-regulated the protein and mRNA levels of PPARγ （P<0.05， P<0.01）. In addition， PPARγ inhibitor + low-dose icariin down-regulated the protein level of CD36 （P<0.01） and PPARγ inhibitor + low-/medium-dose icariin up-regulated the protein level of Rac1 （P<0.05）. ConclusionIcariin ameliorates the cigarette smoke extract-induced efferocytosis dysfunction of alveolar macrophage by regulating the PPARγ signaling pathway and cytoskeletal structure rearrangement.

Objective To explore the molecular mechanism of CAFs promoting energy metabolism of EC9706 cells by collecting conditioned media of cancer-associated fibroblasts(CAFs).Methods Cell viability was detected by MTT,and the CAFs conditioned medium(CAFM)most suitable for indirect co-culture was selected with EC9706 cultured in DMEM high glucose medium as control.The contents of lactic acid and glucose in the supernatant of EC9706 cells were determined by colorimetry.The energy metabolism of EC9706 cells in DMEM and CAFM was detected by seahorse system energy metabolism analysis system.Real time quantitative polymerase chain reaction(RT-qPCR)and western blotting were used to detect the mRNA and protein expression of energy metabolism related molecules.Results Compared with normal esophageal fibroblast conditioned medium(NFM),CAFs conditioned medium of 50%-60%and 70%-80%cell fusion degree promoted the proliferation of EC9706 cells(P<0.01),and CAFM groups with 70%-80%cell fusion degree promoted the proliferation of EC9706 cells compared with the control group.When the CAFM content was 60%,the proliferation of EC9706 cells was significantly increased(P<0.01).Compared with DMEM,CAFM could increase glucose uptake,superlactate content,basal respiratory value,basal glycolysis,compensatory glycolysis(P<0.05),non-mitochondrial oxygen consumption,maximum respiratory value,oxygen consumption for ATP synthesis,and reserve respiratory capacity(P<0.01)of EC9706 cells.RT-qPCR results showed that CAFM could also up-regulate the Hypoxic-inducible factor-1α(HIF-1α),Hexokinase-2(HK2)and Monocarboxylic acid transporter 1(MCT1)of EC9706 cells(P<0.05).Expression of Glucose transporter 1(GLUT1),Pyruvate kinase 2(PKM2)mRNA(P<0.01).Western blot showed that compared with DMEM,the protein expression of HK2,PKM2,MCT1 and GLUT1 was significantly increased(P<0.01).Conclusion CAFM can promote energy metabolism of EC9706 cells by promoting mRNA and protein expressions of HK2,PKM2,HK2,GLUT1,MCT1 and MCT4 under in vitro culture conditions.

Objective:To explore the tracking accuracy of the surface optically guided tracking system (OGTS) in radiotherapy.Methods:Phantom verification and clinical trial verification were adopted. Specialized equipment was employed for the phantom verification. Specifically, the displacement of the optical markers as they moved from a predetermined position to the target position on the reflector ball platform was captured using the OGTS, and then the obtained displacement was compared with the fixed distance within the phantom to calculate the accuracy and repeatability of the OGTS. For the clinical trial verification, 45 patients treated with radiotherapy, which consisted of 15 cases with head, breast, and rectal tumors each, were selected to investigate the tracking accuracy and repeatability of the OGTS. For each patient, the values derived from the image-guided positioning system (IGPS) and the OGTS before and after image-guided setup error correction during three times of fractionated radiotherapy were randomly obtained. The translational errors of each error correction were also recorded. Before radiotherapy, patients′ setup errors were corrected and relevant data were obtained using the IGPS. The correction result of translation errors obtained using the IGPS served as a gold standard to verify the accuracy of the OGTS in monitoring the translational motion of patients. Finally, the comprehensive translational deviation of both method was calculated.Results:The phantom measurements showed that the comprehensive translational deviation for tracking accuracy and tracking repeatability of the OGTS had a maximum deviation and a standard deviation of 0.18 mm and 0.03 mm, respectively. The clinical trial result indicated that the tracking accuracy of IGPS and OGTS exhibited statistically significant differences only for the head in the z direction ( t = 2.21, P < 0.05). Conversely, no statistically significant differences were observed for the head in the remaining directions or for the breast and rectum in the three translational directions ( P > 0.05). The analysis showed that comprehensive translational deviations for the head, breast, and rectum derived from OGTS and IGPS were (0.91±0.62), (1.64±1.30), and (1.52±1.29) mm, respectively, satisfying the requirement that the deviations should be below 2 mm. Conclusions:The OGTS, featuring easy operation and high tracking accuracy, can assist the IGPS in real-time respiratory monitoring during radiotherapy.

Objective:To evaluate the clinical application value of MR amide proton transfer weighted imaging (APTWI) in predicting the pathological grade of brainstem glioma (BSG).Methods:The data of 41 BSG patients in Beijing Tiantan Hospital, Capital Medical University from August 2019 to June 2020 who underwent both MRI and APTWI 2 weeks before surgery and had pathological grading results were retrospectively analyzed. According to the pathological results, 41 patients were classified into high-grade BSG (20 patients) and low-grade BSG (21 patients). Combined with conventional MR images, the signal intensity (%) of amide proton transfer (APT) in the parenchymal area of the tumor was obtained on APTWI images. χ 2 test or independent sample t-test was used to analyze the differences in gender distribution, age and APT signal intensity between patients with high and low grade BSG. Receiver operating characteristic (ROC) curve was drawn to predict the efficacy of APT signal intensity in the differential diagnosis of high and low grade BSG, and Youden index was calculated to obtain the optimal diagnostic threshold; the predictive ability of APT signal intensity was analyzed in combination with Hosmer-Lemeshow goodness of fit test. Results:There was no significant difference in age [(23±18) years, (20±17) years, t=0.97, P=0.340] and gender distribution (9/11, 9/12 for males/females, χ 2=0.02, P=0.890) between high-grade and low-grade BSG patients. The APT signal intensity of high-grade BSG [(3.9±0.9)%] was significantly higher than that of low-grade BSG [(2.8±0.9)%], and the difference had statistical significance ( t=4.16, P<0.001). The area under the ROC curve of APT signal intensity to distinguish high-grade and low grade BSG was 0.836, and with 2.85% as the optimal diagnostic threshold of APT signal intensity, its sensitivity for the diagnosis of high-grade BSG was 90.0% and specificity was 71.4%. The Hosmer-Lemeshow test showed that APTWI had a good predictive ability for BSG grade (χ 2=13.33, P=0.101). Conclusion:APTWI can be applied in distinguishing high grade BSG from low grade BSG, and has clinical value in predicting glioma grading.

Objective:To explore the application value of skin lead marker combined with iSCOUT image-guided positioning system in monitoring and correcting the setup error of intensity-modulated radiotherapy (IMRT) for breast cancer and calculate the PTV margin, aiming to provide reference for clinical practice.Methods:25 breast cancer patients treated with IMRT after modified radical mastectomy in Fujian Medical University Union Hospital from April to August 2019 were enrolled in this study. The skin lead marker combined with iSCOUT image-guided positioning system was employed for image-guided positioning based on the gold standard registration algorithm. Initial setup errors on the x (lateral), y (craniocaudal) and z (anteroposterior) axis and residual errors after the position correction were recorded and analyzed. The effect of the errors before and after image-guided correction upon the plan dose was compared and the reasonable PTV margin was calculated.Results:25 patients received 150 times of positioning verification using skin lead marker combined with iSCOUT image-guided positioning system. The absolute residual errors on the x-, y-and z-axis were (1.53±0.96), (1.30±0.99) and (1.34±0.92) mm, significantly smaller than the initial setup errors of (2.63±2.12), (2.41±2.45) and (3.07±2.77) mm (all P<0.001). The percentage of dose deviation due to residual errors was also smaller than that of the initial errors. Significant differences were observed in D 98%, D 2%, D max of PTV, D max of the heart, D max of the healthy breast, and D mean of the affected lung and both lungs. The percentage deviation from the original plan was decreased from 2.18%, 3.19%, 10.66%, 8.75%, 48.21%, 10.50%, and 3.66% to 0.38%, 0.23%, 2.31%, 0.04%, 13.78%, 6.35% and 0.41%, respectively (all P<0.05). PTV margins on the x-, y-and z-axis after correction were calculated as 1.87, 1.75 and 1.69 mm, respectively. Conclusion:It is feasible and valuable to apply the skin lead marker combined with iSCOUT image-guided positioning system in the positioning verification and correction of breast cancer radiotherapy position, providing novel reference for clinical PTV margin.

To investigate the mutation site of pathogenic gene in patients with hypertrophic cardiomyopathy (HCM) and to analyze the relationship between the genotype and clinical phenotype. Methods: Targeted exon capture sequencing was conducted in a HCM proband for 30 coding exons related HCM gene by all exon amplification and high-throughput sequencing. Furthermore, Sanger sequencing was performed in other family member and in 200 healthy volunteers for verification. The familial investigation included in clinical presentation, physical examination, electrocardiogram and echocardiography. Results: There were 3/6 blood relatives carrying cardiac myosin-binding protein gene MyBPC3 G772A heterozygous mutation, the mutation site was at 258 amino acid of MyBPC3 as glutamic acid (Glu) was substitute to lysine (Lys), such mutation was not found in rest of family member and not in healthy volunteers. The onset of proband and her daughter was rather late, they had palpitation and chest tightness; echocardiography showed interventricular septum basal segment thickening (16-18) mm. Proband was complicating paroxysmal ventricular tachycardia, malignant arrhythmia and heart failure, the maximum pressure gradient of left ventricular outflow was 56 mmHg, which with the high risk for sudden death. Conclusion: Comprehensive gene test has been helpful for clinical stratification, early diagnosis and treatment. MYBPC3 site mutation c.G772A might be the pathogenic mutation in that specific HCM family.

Objective To analyze and evaluate the population genetic quality of 3 subbreeds of China Agricultural University miniature pigs in Beijing.Method According to the local standard DB11/T828.3 -2011, 25 pairs of microsatellite primers were used in 3 subbreeds of China Agricultural University miniature pigs, and software Popgen32 was used to process the data.Results 24 microsatellite loci shared 130, 122 and 138 alleles in the China Agricultural University miniature pigs I, II, III, respectively. The average heterozygosity was 0.6759, 0.5967 and 0.6779, respectively, while the average polymorphism information content ( PIC) was 0.6344, 0.5540 and 0.6403, respectively. The genetic distance between China Agricultural University miniature pig II and III was 0.4251, while the genetic distance between China Agricultural University miniature pig I and II was 0.2084.Conclusions In the 3 subbreeds, China Agricultural University miniature pigs II and III have genetic stability and genetic diversity, and both of which satisfy with the genetic characteristics of closed colony laboratory animal.

Objective To acquire the prevalence and molecular identification data on Syphacia muris and provide reference for the revision of national standard. Methods 923 batches of 5199 SPF animals ( including one batch of 5 monkeys, 3 batches of 25 mini?pigs, 28 batches of 55 rabbits, 13 batches of 248 hamsters, 37 batches of 198 guinea pigs, 93 batches of 459 rats, 742 batches of 4179 mice, 5 batches of 25 chickens and one batch of 5 ducks) and 145 batches of 1389 clean animals ( including one batch of 3 rabbits, 4 batches of 31 hamsters, 16 batches of 157 guinea pigs, 32 batches of 268 rats and 92 batches of 930 mice ) came from 50 different manufactures in China. Direct microscopy real?time dynamic video recording techniques in combination with morphological identification method were applied to screen the Syphacia muris infestation. A multiple polymerase chain reaction ( multiple?PCR ) testing of the isolate based on amplification of the conserved portions of the Syphacia muris internal transcribed spacer (ITS), 28S ribosomal RNA (28S rRNA), NADH dehydrogenase subunits 1 (nad1) and cytochrome c oxidase subunit 1 (cox1) genes, and the molecular sequencing of the multiple?PCR amplicons was used to confirm the Syphacia muris infection. Results Syphacia muris eggs, larvae and adults were detected by using direct microscopy real?time dynamic video recording technique. Syphacia muris were detected based on the morphology and size of ovum, larvae, and female and male adult worms. Multiple?PCR and sequencing were performed to identify ITS, 28S rRNA, nad1 and cox1 genes of DNA extracted from the single egg, larva and adult parasite Syphacia muris. This approach allowed the specific identification with no amplicon being amplified from heterogeneous DNA samples, and sequencing confirmed the identity of the amplified sequences. Molecular characterization by multiple?PCR amplification and sequencing of the ITS, 28S rRNA, nad1 and cox1 genes demonstrated the presence of Syphacia muris. Multiple?PCR followed by sequencing confirmed 285 of 5199 SPF and 135 of 1389 clean animal samples classified as positive by using direct microscopy real?time dynamic video recording technique in the study as containing Syphacia muris?specific DNA. Comparison of the partial sequences of the ITS, 28S rRNA, nad1 and cox1 genes revealed 100% similarity amongst Syphacia muris from different animals. The prevalence of Syphacia muris infection in SPF and clean animals were 5?5% (285/5199) and 9?7% (135/1389), respectively. Conclusions Direct microscopy real?time dynamic video recording technique, multiple?PCR and sequencing can be used to rapidly detect and accurately identify Syphacia muris. The zoonotic nature of Syphacia muris can be regard as a public health alter, hence the good quality control of animal has an important role in protecting human health and safeguarding people safety. This is the first molecular identification and infection investigation of Syphacia muris in SPF and clean animals in China.