Objective:To validate the effectiveness of the leaf position data of multi-leaf collimator (MLC) recorded in the Infinity medical linear accelerator log file (LF).Methods:In this study, the establishment of the film dose calibration curve involved two steps. Initially, the pixel values obtained from scanning the film were converted into net optical density values. Subsequently, a sixth-order polynomial fit was performed on the net optical density and dose data. The picket fence (PF) tests were performed on the electronic portal imaging device (EPID) and film, and the corresponding acquired PF test images were analyzed using the relative leaf travel distance, relative leaf position, relative leaf pair full-width half -maximum (FWHM), and relative leaf pair neighbor region width analysis index, and compared with the relevant results in LF. In addition, to investigate the effect of gravity on the recorded leaf position data by the Infinity medical linear accelerator LF, the above PF tests were executed at 0°, 90°, 180°, and 270° gantry angles, respectively. Intergroup differences were assessed with the Wilcoxon rank-sum test.Results:The film dose calibration curve demonstrated high goodness-of-fit, with a correlation coefficient ( R2) of 0.9994. Across all gantry angles, the dispersion of overall leaf position data for EBT3 film, EPID, and LF followed a consistent pattern based on four analysis metrics: EBT3 film > EPID > LF. Moreover, for each analysis metric, inter-tool differences in standard deviations of results were consistently below 0.1 mm, and this pattern was invariant to gantry angle. Conclusions:The leaf position data recorded in the Infinity medical linear accelerator LF have a high degree of accuracy, and can be used as reference for the actual position of the MLC leaf. Furthermore, gravitational forces exhibit negligible impact on leaf position data acquired via LF.

To understand the background of Escherichia coli(E.coli)carried by artificially bred sika deer and the biological characteristics of the isolated strains,such as drug resistance and pathogenicity,in April 2024,we collected 184 fresh deer fecal samples from four deer farms in Luxiang Township,Shuangyang District,Changchun City,Jilin Province,for isolation and cultivation of E.coli.The isolates were tested for drug resistance and biochemical identification with a BD PhoenixTM-100 Automated Microbiology System.The virulence genes were detected with PCR,and the strains were molecularly typed with ERIC-PCR.A total of 165 E.coli strains were isolated from 184 samples of deer feces,with an isolation rate of 89.67%.Twenty strains had a drug resistance phenotype,and the drug resistance rate was 12.12%;these strains included 15 strains of multi-drug resistant bacteria and 11 strains of ESBL-producing bacteria.Virulence gene detection indicated that the sika deer isolates carried multiple diarrhea-associated virulence genes,such as EAST-1(12.12%),eae(1.21%),stx1(7.88%),stx2(7.27%),and STa(1.82%).ERIC-PCR demonstrated that the isolates showed high polymorphism.The ESBL-producing E.coli carried by sika deer are likely to spread drug resistance in the community and livestock population.Some isolates carried multiple diarrhea-associated virulence genes,thus posing a human transmission risk.Therefore,monitoring of drug resistance and virulence genes must be strengthened,and antibiotics must be used reasonably during the breeding process to avoid excessive use and misuse.

The existing relevant standards and registration of disposable sterile surgical drapes were introduced,and four times of national supervision and sample inspection of disposable sterile surgical drapes from 2017 to 2023 were described.The unqualified items found in the supervision and sample inspection were analyzed,the exploratory research projects carried out were summarized and other problems encountered during the sample inspection were pointed out.Relevant enterprises were suggested to strengthen the implementation of industry standards,take seriously the product material identification information,clearly limit the raw materials used and standardize the product registration name.References were provided for the industrial supervision and development of disposable sterile surgical drapes.[Chinese Medical Equipment Journal,2025,46(5):66-72]

Objective : To construct a humanized mouse model of the interleukin-9 receptor(IL-9R) coding DNA sequence(CDS) gene and to verify the genotype and IL-9R expression in mice. Methods : The CRISPR/Cas9 genome editing technology was used to replace the exon 2-7 fragment of the il-9r gene in mouse embryonic stem cells with the corresponding human IL-9R sequence. After verifying the completion of the gene fragment replacement, tetraploid embryos were constructed and microinjected back into the oviducts of surrogate mice. Through surrogacy by female mice, homozygous humanized mice were obtained. DNA was extracted from the homozygous humanized mice IL-9R CDS gene, and their genotypes were identified by agarose gel electrophoresis after PCR amplification. Western blot was used to detect the expression of IL-9R in the spleen and thymus of homozygous humanized mice with either wild-type(WT) or IL-9R gene humanization. Results : Gel electrophoresis after PCR amplification showed that mice with only a 1 805 bp band amplified using WT primers were wild-type, while mice with 2 553 bp and 2 340 bp bands amplified using 5KI and 3KI primers, respectively, were homozygous humanized mice with IL-9R CDS gene. Western blot results indicated that the tissues of homozygous humanized mice model with IL-9R CDS gene expressed IL-9R significantly. Conclusion The humanized mouse model with IL-9R CDS gene has been successfully constructed and characterized.

Objective: To explore the breeding and genotyping of CCR2 knockout mice, and to verify the applicability of the polymerase chain reaction(PCR) method for genotype detection of CCR2 knockout mice. Methods: The introduced CCR2 pure male mice and wild-type female mice were mated and bred to produce the offspring generation, the obtained F1 generation heterozygous mice were continued to be mated. DNA was extracted by clipping the tail tissues of the mice at the age of 2 weeks, the target gene fragment was amplified by PCR, and the genotypic results were determined by agarose gel electrophoresis. The proportion of purebred progeny carrying the CCR2 knockout gene was increased by genetic crosses, the effect of CCR2 knockout in the progeny mice was verified by using Western blot against major immune cells and key organs, and flow cytometry was used to detect whether the knockout of the CCR2 gene had any effect on the function of the immune system by targeting the major immune cells. Results: CCR2 knockout mice were successfully bred and characterized, and three genotypes of F2 generation mice were obtained: CCR2+/+, CCR2+/-, and CCR2-/-. The offspring genotypes were identified by PCR, and Western blot showed extremely low CCR2 protein expression in CCR2 knockout mice. Flow analysis showed that CCR2 knockdown reduced the expression of CD4+T and Th1 cells in mouse spleen-derived T cells, but did not affect macrophage function. Conclusion Correct breeding and identification are important ways to get the pure CCR2 knockout mice, and PCR method for identifying mouse genotypes is simple, fast and reliable.

OBJECTIVE: The relationship between fish consumption and stroke is inconsistent, and it is uncertain whether this association varies across predicted stroke risks. METHODS: A cohort study comprising 95,800 participants from the Prediction for Atherosclerotic Cardiovascular Disease Risk in China project was conducted. A standardized questionnaire was used to collect data on fish consumption. Participants were stratified into low- and moderate-to-high-risk categories based on their 10-year stroke risk prediction scores. Hazard ratios ( HRs) and 95% confidence intervals ( CIs) were estimated using Cox proportional hazard models and additive interaction by relative excess risk due to interaction (RERI), attributable proportion (AP), and synergy index (SI). RESULTS: During 703,869 person-years of follow-up, 2,773 incident stroke events were identified. Higher fish consumption was associated with a lower risk of stroke, particularly among moderate-to-high-risk individuals ( HR = 0.53, 95% CI: 0.47-0.60) than among low-risk individuals ( HR = 0.64, 95% CI: 0.49-0.85). A significant additive interaction between fish consumption and predicted stroke risk was observed (RERI = 4.08, 95% CI: 2.80-5.36; SI = 1.64, 95% CI: 1.42-1.89; AP = 0.36, 95% CI: 0.28-0.43). CONCLUSION Higher fish consumption was associated with a lower risk of stroke, and this beneficial association was more pronounced in individuals with moderate-to-high stroke risk.
Humans ; China/epidemiology* ; Male ; Female ; Stroke/etiology* ; Middle Aged ; Prospective Studies ; Incidence ; Aged ; Animals ; Fishes ; Risk Factors ; Diet ; Seafood ; Adult ; Cohort Studies

Objective:To discuss the expression and clinical significance of inositol polyphosphate-4-phosphatase type Ⅱ(INPP4B)gene in hepatocellular carcinoma(HCC)based on The Cancer Genome Atlas(TCGA)database and experimental verification with clinical samples.Methods:Based on data from 424 clinical samples in the TCGA database(including 374 HCC tissues and 50 paracarcinoma tissues),Kaplan-Meier method and Cox regression analysis were used to evaluate the relationship between INPP4B gene and the clinical characteristics and survival prognosis of the HCC patients.The correlations between INPP4B gene and the number of 24 types of immune cells,matrix,immune cell infiltration and tumor purity in tumor tissue,and the expression level of the high-frequency mutant gene tumor protein 53(TP53)in HCC were analyzed.The clinicopathological data and paraffin-embedded tissue sections of 60 HCC patients treated with surgical resection from December 2022 to December 2023 were collected.According to clinical diagnosis,they were divided into poorly differentiated group(HCC-L group),moderately differentiated group(HCC-M group)and well-differentiated group(HCC-H group),with 20 cases in each group;20 patients during the same period who underwent biopsy and were pathologically diagnosed as non-tumor were selected as normal group,and their clinicopathologic data and liver tissue paraffin sections were collected.HE staining was used to observe the pathomorphology of HCC tissue and normal liver tissue of the subjects in various groups;immunohistochemistry method was used to detect the expressions of Ki-67 and INPP4B proteins in the HCC tissue and normal liver tissue of the subjects in various groups.Results:The TCGA database analysis results showed that compared with normal tissue,the expression level of INPP4B mRNA in HCC tissue was significantly increased(P<0.01).Compared with INPP4B low expression group,the overall survival(OS)of the patients in INPP4B high expression group was significantly prolonged(P<0.05).The univariate Cox regression analysis results showed that tumor stage,pathological stage,tumor status and residual tumor had impacts on OS of the HCC patients(P<0.05).The univariate regression analysis results showed that the INPP4B prognostic risk model score ratio was HR=0.781,95％confidence interval(CI):0.552-1.105,P=0.168.The AUC value for the impact of INPP4B on OS of the HCC patients was 0.558,indicating that the INPP4B gene prognostic risk model had certain predictive value in survival prognosis.The INPP4B mRNA expression level was not correlated with TNM stage,stage,patient gender,age,race or body mass index(BMI)(P>0.05).In tumor tissue with high and low INPP4B expression,22 types of immune cells showed statistically significant differences(P<0.05);the INPP4B mRNA expression level was positively correlated with the number of 23 types of immune cells except T helper(Th)17 cells(r>0),among which all Th cells except natural killer(NK)CD56+cells were statistically significant(P<0.01);INPP4B was significantly correlated with matrix(r=0.475),immune cell infiltration(r=0.641)and tumor purity(r=0.599)in tumor tissue(P<0.01).INPP4B was correlated with TP53(r=0.287,P<0.01).The HE staining results showed that clear and complete lobular structure,neatly arranged cells and slight inflammatory cell infiltration were observed in liver tissue of the subjects in normal group;completely destroyed lobular structure,significant hepatocellular steatosis,massive inflammatory cell infiltration,and lesions such as ballooning degeneration and small cell hyperplasia in some cells were observed in HCC tissue of the patients in HCC-L,HCC-M and HCC-H groups,and the lower the HCC differentiation degree,the more severe the tissue destruction;The immunohistochemistry results showed that compared with normal group,the expression levels of Ki-67 protein in HCC tissue of the patients in HCC-L,HCC-M and HCC-H groups were significantly increased(P<0.01),and the lower the differentiation degree of the HCC patients,the higher the Ki-67 positive rate.Brownish-yellow granules evenly distributed in the cells and INPP4B protein was highly expressed in liver tissue of the subjects in normal group;compared with normal group,the expression levels of INPP4B protein in HCC tissue of the patients in HCC-L,HCC-M and HCC-H groups were significantly decreased(P<0.01),and the lower the differentiation degree of the HCC tissue,the lower the INPP4B positive rate.Conclusion:INPP4B is a protective factor for the prognosis of HCC patients;as a new tumor suppressor gene,INPP4B may become a potential target for new drug screening in HCC treatment.

Objective:To investigate the self-perceived cognitive decline status in the community population,and to explore the association between different dietary habits and self-perceived cognitive decline.Methods:A cross-sectional study was carried out in 11 879 community residents in the three regions of Weifang,Jining,and Zoucheng in Shandong Province.The Ascertain Dementia-8 and dietary habits information questionnaire were used to assess self-perceived cognitive decline and dietary habits,and their association were analyzed using single factor and multivariate logistic regression.Results:The detection rate of self-perceived cognitive decline was 21.4％.Lo-gistic regression showed that smoking in the past was positively associated with self-perceived cognitive decline(OR=1.40,95％CI:1.14-1.73).However,intake of fruits(often,OR=0.70,95％CI:0.52-0.94;everyday,OR=0.60,95％CI:0.44-0.81),nuts(daily,OR=0.62,95％CI:0.44-0.88),mushrooms(often,OR=0.74,95％CI:0.57-0.92)and high tryptophan foods(sometimes,OR=0.79,95％CI:0.68-0.91;everyday,OR=0.54,95％CI:0.34-0.87)were negatively associated with self-perceived cognitive decline.Conclusion:Smoking history might be a risk factor for self-perceived cognitive decline,and high frequency intake of fruits,nuts,mush-rooms,and high tryptophan foods might protective factors for it.