The increasing frequency of radiographic diagnostic imaging and the cumulative dose to the public from radiation has raised widespread concerns. However, accurate measurement of the radiation dose received by the human body is difficult to achieve. Monte Carlo simulation, as a numerical computational method guided by probability statistics theory, has been applied to various dose assessments, imaging optimizations, and radiation protection in radiographic diagnostic imaging. We provide a comprehensive review of the principles of the Monte Carlo method, the modelling process of Monte Carlo simulation and the progress of its application to diagnostic radiological dose estimation.

Objective To isolate the Japanese encephalitis virus carried by Culex tritaeniorhynchus in Dongchuan District of Yunnan Province and analyze its molecular characteristics, so as to provide insights into the prevention and control of Japanese encephalitis in Yunnan Province. Methods Mosquito specimens were collected using mosquito-trapping lamps from pig farms in Batang Village and Xiaoxin Village, Dongchuan District, Kunming City, Yunnan Province in July 2016, and the mosquito species was identified according to the mosquito morphology. Then, 60 to 100 mosquitoes of each species served as a group and were ground. Baby hamster kidney-21 (BHK-21) cells and Aedes albopictus clone C6/36 cells were used for virus isolation, and positive isolates were identified using flavivirus primers. The positive isolates were amplified using reverse transcription polymerase chain reaction (RT-PCR) assay with 15 pairs of specific primers covering the full length of the genotype I Japanese encephalitis virus, and DNA sequence assembly was performed using the software SeqMan in the DNASTAR package. The obtained sequences were aligned with the complete sequences of 38 Japanese encephalitis virus downloaded from the GenBank with the software MegAlign, and the nucleotide and amino acid homology analyses of the obtained sequences were performed. The difference in amino acid sites was analyzed with the software GeneDoc, and phylogenetic trees were created based on the sequences of the coding region and E protein of the isolated Japanese encephalitis virus with the software Mega X. In addition, the secondary and tertiary structures of the E protein of the Japanese encephalitis virus were predicted using the online tool SOPMA and the software Swiss-Model. Results A total of 5 820 mosquitoes were collected and 3 843 Cx. tritaeniorhynchus (66.03%) were identified according to the mosquito morphology. A positive virus isolate, termed YNDC55-33, was isolated from Cx. tritaeniorhynchoides following batches of virus isolation from mosquito specimens, and cytopathic effect was observed following inoculation into BHK-21 and C6/36 cells. The YNDC55-33 virus isolate was successfully amplified with the flavivirus primes, and a long sequence containing 300 nucleotides was obtained. Following sequence alignment using the BLAST tool, the sequence of the YNDC55-33 virus isolate had high homology with that of the genotype I Japanese encephalitis virus. A long sequence with 10 845 nucleotides in length, which encoded 3 432 amino acids, was obtained by splicing the full sequence of the YNDC55-33 virus isolate. Phylogenetic analysis based on the whole-genome sequence and E gene sequence of the YNDC55-33 virus isolate showed that the new YNDC55-33 virus isolate was most closely related to the genotype I Guizhou isolate (GenBank accession number: HM366552), with nucleotide homology of 98.5% and amino acid homology of 99.4%, and the YNDC55-33 virus isolate shared 97.96% ± 0.33% nucleotide homology and 99.35% ± 0.08% amino acid homology with other genotype I Japanese encephalitis virus isolates, and < 90% nucleotide homology and < 98% amino acid homology with other genotypes of Japanese encephalitis virus. The YNDC55-33 virus isolate and the live attenuated virus vaccine candidate SA14-14-2 isolate differed at 16 amino acid sites on E gene, and 7 out of 8 key amino acid sites related to neurovirulence. The secondary and tertiary structures of the E protein of the YNDC55-33 virus isolate were predicted to be characterized by random coils. Conclusions A genotype I Japanese encephalitis virus was isolated from Cx. tritaeniorhynchus in Dongchuan District, Kunming City. This virus isolate and the live attenuated virus vaccine candidate SA14-14-2 isolate does not differ at antigenic epitopes-related key amino acid sites, and the major protein structure of the virus isolate is random coils. This study adds new data for the epidemiological distribution of Japanese encephalitis virus in Yunnan Province, which may provide insights into the prevention and control of Japanese encephalitis in the province.

Objective To understand the genotyping of human immunodeficiency virus (HIV) co-infected hepatitis C virus (HCV) patients in Yunnan Province, and to analyze the differences in viral load, biochemical indicators, and blood routine indicators among different genotypes, in order to provide a laboratory basis for the diagnosis and clinical treatment of HIV/HCV co-infected patients. Methods From November 2022 to June 2023, the serum samples and basic information of patients diagnosed with HIV/HCV co-infection were collected in the antiviral outpatient clinic of Yunnan Provincial Hospital of Infectious Diseases. The HCV viral load was detected by one-step qRT-PCR amplification, the positive samples were sequenced, and genotyping was determined based on NS5 gene sequence. The differences in biochemical and blood routine indexes between HIV patients co-infected with different HCV genotypes and low/high viral loads were analyzed. Results A total of 126 HIV/HCV co-infected patients were collected, including 20 HCV genotype 1 (15.9%), 91 HCV genotype 3 (72.2%), and 15 HCV genotype 6 (11.9%). The maximum and minimum viral load of the three HCV genotypes were as follows: HCV type 1 (1.0×108, 4.8×104 IU/mL), HCV type 3 (2.2×108, 2.9×102 IU/mL), and HCV type 6 (8.1×107, 6.8×104 IU/mL). The results showed that there was no significant difference between HIV co-infection with different genotypes of HCV and three HIV treatment schemes, including nucleoside reverse transcriptase inhibitors+integrase strand transfer inhibitors (NRTIs+INSTIs), nucleoside reverse transcriptase inhibitors+non-nucleoside reverse transcriptase inhibitors (NRTIs+NNRTIs) and nucleoside reverse transcriptase inhibitors+protease inhibitor (NRTIs+PLs), and the viral load of patients (P>0.05). The analysis of biochemical indexes such as total bilirubin (TBIL), direct bilirubin (DBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (CREA), and blood routine indexes such as white blood cell (WBC), red blood cell (RBC), hemoglobin (HGB), platelet (PLT), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) among different HCV genotypes and low/high viral loads showed that there was no significant difference in biochemical indexes and blood routine indexes between low/high viral loads of HIV co-infected HCV patients (P>0.05); however, the biochemical indicators TBIL, IBIL and MCHC were significantly different statistically between patients with genotype 3 HCV infection and those with genotype 1 HCV infection (P<0.05), while other biochemical and blood routine indexes were not statistically different among different HCV genotypes (P>0.05). Conclusions There are six subtypes of HCV co-infection in HIV patients in Kunming, Yunnan Province, including three genes of genotype 1, 3, and 6. Among them, genotype 3 HCV is the main prevalent genetic virus among HIV co-infected populations. The TBIL, IBIL and MCHC values of HIV patients co-infected with HCV type 3 are different from those infected with HCV type 1.

Objective:To investigate the characteristics of the CD8+T cells infiltration from the 4 sub-types in medulloblastoma(MB),to analyze the relationship between CD8+T cells infiltration and prog-nosis,to study the function of C-X-C motif chemokine ligand 11(CXCL11)and its receptor in CD8+T cells infiltration into tumors and to explore the potential mechanism,and to provide the necessary clinico-pathological basis for exploring the immunotherapy of MB.Methods:In the study,48 clinical MB sam-ples(12 cases in each of 4 subtypes)were selected from the multiple medical center from 2012 to 2019.The transcriptomics analysis for the tumor of 48 clinical samples was conducted on the NanoString Pan-Cancer 10360?Panel(NanoString Technologies).Immunohistochemistry(IHC)staining of formalin-fixed,paraffin-embedded sections from MB was carried out using CD8 primary antibody to analyze diffe-rential quantities of CD8+T cells in the MB four subtypes.Through bioinformatics analysis,the relation-ship between CD8+T cells infiltration and prognosis of the patients and the expression differences of various chemokines in the different subtypes of MB were investigated.The expression of CXCR3 receptor on the surface of CD8+T cells in MB was verified by double immunofluorescence staining,and the under-lying molecular mechanism of CD8+T cells infiltration into the tumor was explored.Results:The charac-teristic index of CD8+T cells in the WNT subtype of MB was relatively high,suggesting that the number of CD8+T cells in the WNT subtype was significantly higher than that in the other three subtypes,which was confirmed by CD8 immunohistochemical staining and Gene Expression Omnibus(GEO)database analysis by using R2 online data analysis platform.And the increase of CD8+T cells infiltration was posi-tively correlated with the patient survival.The expression level of CXCL11 in the WNT subtype MB was significantly higher than that of the other three subtypes.Immunofluorescence staining showed the presence of CXCL11 receptor,CXCR3,on the surface of CD8+T cells,suggesting that the CD8+T cells might be attracted to the MB microenvironment by CXCL11 through CXCR3.Conclusion:The CD8+T cells infiltrate more in the WNT subtype MB than other subtypes.The mechanism may be related to the activation of CXCL11-CXCR3 chemokine system,and the patients with more infiltration of CD8+T cells in tumor have better prognosis.This finding may provide the necessary clinicopathological basis for the regulatory mechanism of CD8+T cells infiltration in MB,and give a new potential therapeutic target for the future immunotherapy of MB.

Objective To determine and analyze the content of 45 inorganic elements in Fufang Xiling Jiedu preparation and to provide a reference for the safety detection of Fufang Xiling Jiedu preparation.Methods Inductively coupled plasma mass spectrometry(ICP-MS)was used to ascertain the concentrations of 45 inorganic elements,including Li,B,Al,K,Zn and As from 16 batches of Fufang Xiling Jiedu preparation which were gathered.The content determination findings were plotted as heatmaps,Pearson correlation analysis plot,PCA scatter plots,fingerprints,and control maps.The Pearson correlation analysis and PCA analysis were performed on the content determination results of 16 batches using SPSS 21.0,to evaluate the safety and quality uniformity of Fufang Xiling Jiedu preparation.Results The inorganic elements in Fufang Xiling Jiedu preparation were dominated by K and Ca.The content of different elements in the sample could be categorised into 5 levels.The content of various elements in different batches of Fufang Xiling Jiedu preparation was similar.Pb,Cd,As,Hg and Cu were all within the safety limit as those specified in the Chinese Pharmacopoeia.Co,Y,Sm,Gd,Dy,Th,Al,Si,Fe,Sb and Tl were the characteristic inorganic elements of Fufang Xiling Jiedu preparation.Conclusion This method is easy to operate and suitable for the determination of inorganic elements in Fufang Xiling Jiedu preparation,providing references for the clinical medication safety.

BACKGROUND: Observational research has reported that systemic lupus erythematosus (SLE) is related to common female hormone-dependent cancers, but the underlying causal effect remains undefined. This study aimed to explore the causal association of these conditions by Mendelian randomization (MR) analysis. METHODS: We selected instrumental variables for SLE from genome-wide association studies (GWASs) conducted in European and East Asian populations. The genetic variants for female malignant neoplasms were obtained from corresponding ancestry GWASs. We utilized inverse variance weighted (IVW) as the primary analysis, followed by sensitivity analysis. Furthermore, we conducted multivariable MR (MVMR) to estimate direct effects by adjusting for the body mass index and estradiol. Finally, we implemented reverse direction MR analysis and gave a negative example to test the reliability of MR results. RESULTS: We found SLE was significantly negatively associated with overall endometrial cancer risk (odds ratio [OR] = 0.961, 95% confidence interval [CI] = 0.935-0.987, P  = 3.57E-03) and moderately inversely related to endometrioid endometrial cancer (ENEC) (OR = 0.965, 95% CI = 0.936-0.995, P  = 0.024) risk in the European population by IVW. We replicated these results using other MR models and detected a direct effect by MVMR (overall endometrial cancer, OR = 0.962, 95% CI = 0.941-0.983, P  = 5.11E-04; ENEC, OR = 0.964, 95% CI = 0.940-0.989, P  = 0.005). Moreover, we revealed that SLE was correlated with decreased breast cancer risk (OR = 0.951, 95% CI = 0.918-0.986, P  = 0.006) in the East Asian population by IVW, and the effect was still significant in MVMR (OR = 0.934, 95% CI = 0.859-0.976, P  = 0.002). The statistical powers of positive MR results were all >0.9. CONCLUSION This finding suggests a possible causal effect of SLE on the risk of overall endometrial cancer and breast cancer in European and East Asian populations, respectively, by MR analysis, which compensates for inherent limitations of observational research.
Female ; Humans ; Genome-Wide Association Study ; Mendelian Randomization Analysis ; Neoplasms, Hormone-Dependent ; Reproducibility of Results ; Endometrial Neoplasms ; Lupus Erythematosus, Systemic/genetics* ; Carcinoma, Endometrioid ; Breast Neoplasms ; Polymorphism, Single Nucleotide

Although the development of COVID-19 vaccines has been a remarkable success, the heterogeneous individual antibody generation and decline over time are unknown and still hard to predict. In this study, blood samples were collected from 163 participants who next received two doses of an inactivated COVID-19 vaccine (CoronaVac®) at a 28-day interval. Using TMT-based proteomics, we identified 1,715 serum and 7,342 peripheral blood mononuclear cells (PBMCs) proteins. We proposed two sets of potential biomarkers (seven from serum, five from PBMCs) at baseline using machine learning, and predicted the individual seropositivity 57 days after vaccination (AUC = 0.87). Based on the four PBMC's potential biomarkers, we predicted the antibody persistence until 180 days after vaccination (AUC = 0.79). Our data highlighted characteristic hematological host responses, including altered lymphocyte migration regulation, neutrophil degranulation, and humoral immune response. This study proposed potential blood-derived protein biomarkers before vaccination for predicting heterogeneous antibody generation and decline after COVID-19 vaccination, shedding light on immunization mechanisms and individual booster shot planning.
Humans ; COVID-19 Vaccines ; Leukocytes, Mononuclear ; Proteomics ; COVID-19/prevention & control* ; Vaccination ; Antibodies ; Antibodies, Viral ; Antibodies, Neutralizing

Objective:To evaluate the influence of different detector widths and signal acquisition positions of wide-detector CT in different scanning modes on CT number and noise, and to provide a basis for reasonable selection of scanning modes and related parameters in clinical practice.Methods:The body dose phantom was scanned by GE Revolution CT. The scan was performed with detector widths of 40, 80 and 160 mm in sequential scanning mode and with detector width/pitch combinations of 40 mm/0.516, 40 mm/0.984, 80 mm/0.508 and 80 mm/0.992 in spiral scanning mode. The phantom was placed at the central and peripheral of the selected detector widths, and the adjacent positions between two axial scans. The images of the phantom were evaluated subjectively and the CT numbers and SDs were measured. The differences between the measured values at different imaging parameters were compared. The multi-group Friedman test was used to compare CT numbers and SD under different scanning parameters in sequential scanning mode, and the Wilcoxon test was used to compare CT numbers and SD in spiral scanning mode.Results:There was no statistically significant difference in the geometric shapes of the phantom images obtained at any combination of parameters. In sequential scanning mode, the differences at different detector widths were statistically significant (χ 2=14.00, P=0.001) with CT numbers at 40 mm and 160 mm greater than CT numbers at 80 mm ( P<0.05). The differences at different signal acquisition positions were statistically significant (χ 2=12.04, P=0.002) with CT numbers at peripheral and adjacent greater than CT numbers at central ( P<0.05). In spiral scanning mode CT numbers at detector width at 80 mm were greater than CT numbers at 40 mm ( Z=-2.10, P=0.036). For SD, the differences at different detector widths were statistically significant in sequential scanning modes (χ 2=8.17, P=0.017) with SD at 160 mm greater than SD at 80 mm ( P<0.05). The differences at different signal acquisition positions were statistically significant (χ 2=13.50, P=0.001) with SD at peripheral greater than SD at central ( P<0.05). In spiral scanning mode SDs at pitches 0.984 and 0.992 were greater than SDs at 0.516 and 0.508 ( Z=-2.66, P=0.008). There were no significant differences among other groups. Conclusion:The selection of scanning mode, detector width and signal acquisition position of wide-detector CT will affect the image CT numbers and SDs.

Objective:To investigate the feasibility of the application of low tube potential scanning in dacryocystography CT.Methods:The mixture of iohexol and saline with the ration of 1∶3 as the dacryocyst was set on the nose wing of the head-neck phantom. The phantom was scanned at 80, 100, 120, 140 kV with appropriate mAs to set the volume CT dose index(CTDI vol)at 10, 15, 20, 25, 30, 35 or 40 mGy. All the images were objectively evaluated to find out the optimal scanning parameters of 80 kV/240 mAs with the same contrast-to-noise ratio(CNR)of conventional scanning condition of 120 kV/180 mAs. A total of 62 patients who conducted dacryocystography CT in Beijing Tongren Hospital from November 2019 to July 2020 were prospectively selected. They were randomly divided equally into conventional scanning group with 120 kV/180 mAs and low tube potential group with 80 kV/240 mAs. The CT number, noise (SD) and contrast-to-noise ratio (CNR) of the two groups were measured as the objective evaluation indicators of image quality. The subjective evaluation was performed by two senior radiologists using a double-blind method and a 5-scale system evaluation. Results:For the phantom study, the CNR was positively correlated with CTDI vol under the same tube potential ( r=0.985, 0.965, 0.971, 0.972, P < 0.05). With the same CNR, the radiation dose decreased with lower tube potential. Under the conventional scanning parameters of 120 kV/180 mAs, the CNR was 27.8. At the same CNR, the optimal scanning parameters were 80 kV/240 mAs. For the clinical study, the CTDI vol of conventional scanning group and low tube potential group were 31.2 and 12.8 mGy respectively, 59% decreased in low tube potential group. There were statistically significant differences in CT number of dacryocyst area, CT number of orbital fat area and noise between the two groups ( t=-3.476, 2.601, -5.704, P < 0.05). There was no statistically significante difference in CNR between 2 groups( P>0.05). Two observers had a good consistency ( Kappa >0.75). There was no statistically significante difference in subjective rating between 2 groups( P>0.05). Conclusions:Low tube potential scanning could obtain satisfactory image quality in dacryocystography CT at much lower radiation dose.

Objective:To explore the level of fractional exhaled nitric oxide (FeNO) in preschool children in Beijing and analyze the influencing factors.Methods:Preschool students aged 3-5 in Beijing were selected from May to July 2017.Healthy children were screened through questionnaire survey and on-site physical examination, and their FeNO levels were detected.Results:A total of 317 healthy children were enrolled, including 161 males and 156 females.There was no significant difference in FeNO levels between different genders ( P>0.05). The geometric mean value of FeNO was 8.2 ppb in male(95% CI: 7.0-9.3 ppb)and 8.7 ppb in female (95% CI: 7.4-10.1 ppb). There were statistical differences in FeNO levels among the 3 age groups ( F=4.63, P<0.05). The geometric mean value of FeNO was 7.2 ppb in 3-year-old children (95% CI: 5.5-8.9 ppb), 8.8 ppb in 4-year-old children (95% CI: 7.4-10.2 ppb), and 9.2 ppb in 5-year-old children (95% CI: 7.7-10.7 ppb). The geometric mean value of FeNO of healthy preschool children was 8.5 ppb (95% CI: 7.6-9.3 ppb). There was a positive correlation between FeNO and height ( r=0.135, P<0.05), but there was no significant correlation between FeNO and weight. Conclusions:The geometric mean value of FeNO in healthy preschool children in Beijing is 8.5 ppb (95% CI: 7.6-9.3 ppb)and the 95% reference value is 23.5 ppb.The level of FeNO changes slightly with the increase of age, and height also affects the FeNO.It is highly feasible to use on-line tidal breathing method to measure FeNO of preschool children.