Objective To investigate the current status of quality control of radiological diagnosis and treatment equipment in Shenzhen City, explore the problems in quality control testing of radiological diagnosis and treatment equipment, and provide control strategies. Methods According to the requirements of the Special Monitoring Work Plan for Radiation Health in Shenzhen, quality control tests were carried out on some radiological diagnosis and treatment equipment in Shenzhen according to the test items and methods of the currently valid national standards. Results From 2019 to 2023, a total of 72 medical institutions participated in radiological health monitoring program in Shenzhen, and 839 quality control tests were performed on radiological diagnosis and treatment equipment. The qualified rate was 91.8% in preliminary tests. The qualified rates of radiological diagnosis, radiotherapy, and nuclear medicine equipment were 91.9%, 96.3%, and 62.5%, respectively. The primary unqualified items were response uniformity, flatness of the X-ray irradiation field, and intrinsic spatial linearity. Conclusion The qualified rate in quality control of nuclear medical equipment is relatively low. Medical institutions should strengthen the routine maintenance of radiological diagnosis and treatment equipment. Radiological health technical service institutions should enhance the training of technical personnel to ensure the health and safety of patients and radiation workers.

Objective To analyze the activity concentrations of gross α, gross β, and radionuclides in atmospheric fallout around Daya Bay Nuclear Power Plant from 2019 to 2022, and provide foundational scientific data for the healthy development of nuclear energy. Methods Five monitoring sites were set up at different distances (1.2, 6.9, 12.4, 42.3, and 69.2 km) from Daya Bay Nuclear Island 1. Stainless steel sampling barrels were used to collect atmospheric fallout, with a monitoring cycle of three months. The collected samples were ashed using radiochemical method. Subsequently, the gross α and gross β radioactivity were quantified using a low-background α/β measurement instrument. The remaining ash samples were mixed with water and left to equilibrate for over three weeks before γ-nuclide analysis using a low-background, high-purity germanium γ-spectrometer. Results The gross α activity concentration in atmospheric fallout around Daya Bay Nuclear Power Plant from 2019 to 2022 averaged (25.3 ± 10.6) Bq/m²/season and ranged from 5.8 to 73.4 Bq/m²/season. The gross α activity concentrations in sampling sites #1 to #5 were 5.8-34.4, 11.9-35.2, 14.4-46.4, 7.2-73.4, and 13.1-43.1 Bq/m²/season, respectively. The gross β activity concentration averaged (50.5 ± 23.4) Bq/m²/season and ranged from 13.9 to 139.3 Bq/m²/season. The gross β activity concentrations of sampling sites #1 to #5 were 17.1-107.4, 17.6-87.5, 25.8-102.0, 13.9-139.3, and 23.4-99.2 Bq/m²/season, resprctively. The activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th, ⁴⁰K, ²¹⁰Pb, and ⁷Be in atmospheric fallout were < lower limit of detection (LLD)-4.2, < LLD-5.8, < LLD-6.3, < LLD-42.1, < LLD-514.0, and 35.7-1761.0 Bq/m²/season, respectively. Gross α and gross β activity concentrations were significantly positively correlated with ²¹⁰Pb activity concentration (r=0.770, α < 0.001; r=0.882, α < 0.001, respectively). Gross β activity concentration showed a significant positive correlation with ⁷Be (r=0.833, α < 0.001). The activity concentrations of ⁵⁴Mn, ⁵⁷Co, ⁵⁸Co, ⁶⁰Co, ⁵⁹Fe, ⁹⁵Zr, ¹⁰³Ru, ¹⁰⁶Ru, ^110mAg, ¹³¹I, ¹³⁴Cs, ¹³⁷ Cs, ¹⁴⁰Ba and ¹⁹²Ir were lower than the LLD of the instrument, and no artificial radionuclides were detected. Conclusion The gross α and gross β radioactive activity concentrations in the atmospheric fallout in the surrounding area of Daya Bay Nuclear Power Plant during 2019-2022 were affected by natural radionuclides ²¹⁰Pb and ⁷Be, and were in the normal fluctuation ranges. No artificial radionuclides were found in the atmospheric fallout, and the Daya Bay Nuclear Power Plant was in a safe and stable state of operation.

Cadmium is a non-essential,non-degradable heavy metal element,the accumulation of cadmium can cause kidney damage.The purpose of this study was to reveal the ferroptosis mecha-nism induced by cadmium exposure in porcine kidney PK-15 cells.First of all,cell viability of gradi-ent concentration of cadmium chloride(CdCl2)on PK-15 cells was detected by CCK-8 method to screen suitable work concentration of CdCl2.Secondly,PK-15 cells were treated with 10 μmol/L CdCl2 for 3,6 and 12 h.The contents of lactate dehydrogenase(LDH)malondialdehyde(MDA)were detected by colorimetry,the expression of ferroptosis related protein were detected by West-ern blot,and the content of ferrous ion(Fe2+)was detected by fluorescence probe.Finally,PK-15 cells were pretreated with 10 μmol/L HO-1 inhibitor zinc protoporphyrin(ZnPP)for 6 h,and then treated with 10 μmol/L CdCl2 for 12 h.The morphology of PK-15 cells was observed by phase contrast microscope and the expression of ferroptosis related proteins was detected by West-ern blot.The results showed that CdCl2 treatment caused a significant decrease in cell viability.The levels of LDH,MDA and Fe2+,the protein levels of Nrf2,HO-1 and ALOX5,and the expression level of FTH1 protein were significantly decreased in CdCl2 treatment cells(P＜0.01).ZnPP could significantly improve the ferroptosis of PK-15 cells induced by CdCl2 treatment.Compared with CdCl2 treatment cells,the cell morphology was significantly improved,the protein levels of Nrf2,HO-1 and ALOX5 protein were significantly decreased,and the protein levels of FTH1 protein were significantly increased in ZnPP pretreatment group(P＜0.01).The results showed that cad-mium induced iron overload and lipid peroxidation,which result in ferroptosis in PK-15 cells through Nrf2/HO-1 pathway.

Porcine kidney cell line(PK-15)with HO-1 gene knockout was constructed by CRISPR/Cas9 system to provide experimental materials for exploring the role and molecular mechanism of HO-1 in cadmium-induced ferroptosis in PK-15 cells.Three sgRNA targeting HO-1 gene were de-signed,synthesized and ligated to lentiviral vector Lenti CRISPRv2.The constructed lentiviral plas-mid was transfected into human embryonic cells(HEK293FT)to obtain recombinant lentivirus,which was used to infect PK-15 cells.The monoclonal cell line with HO-1 knockout was obtained by puromycin screening and limited dilution method.The knockout effect was analyzed by sequencing and Western blot detection.The HO-1 gene knockout cells were treated with 10 μmol/L cadmium chloride(CdCl2).The cell viability was detected by CCK-8 method,the cell morpholo-gy was observed by phase contrast microscope,and the content of ferrous ion(Fe2+)was detected by fluorescence probe.The results showed that sgRNA2 possessed the highest editing efficiency.The base insertion or deletion of HO-1 gene and the frameshift of the target gene occurred in all five knockout cells.Western blot results showed that no expression of HO-1 protein was detected,indicating that the PK-15 cell line with HO-1 gene knockout was successfully constructed.After CdCl2 treatment,compared with the control cells,the cell viability was significantly increased and the Fe2+content was significantly decreased in PK-15 cells with HO-1 gene deletion,indicating that HO-1 gene knockout could significantly alleviate the abnormal iron metabolism caused by cadmium treatment.In conclusion,this study successfully constructed a PK-15 cell line knocking out HO-1 gene by using CRISPR/Cas9 gene editing technique,and confirmed that HO-1 plays an important role in iron metabolism abnormality in PK-15 cells induced by cadmium treatment,which lays a foundation for further study on the regulatory mechanism of HO-1 in ferroptosis in PK-15 cells induced by cadmium exposure.

Objective:To analyze the levels of antibody to measles virus in cord blood of newborns in Ankang city, and provide reference for the development of measles prevention and control measures and strategies.Methods:From January to December, 2023, 1 058 pregnant women from 10 county-level general hospitals in Ankang city were recruited in this study. Neonatal umbilical cord blood samples were collected for detecting IgG antibody against measles with ELISA. SPSS 21.0 software was used to analyze the positive rate of antibody to measles virus and the influencing factors.Results:The overall positive rate of IgG antibody to measles virus was 89.22% (944/1 058), and the geometric mean concentration (GMC) was 570.26 mlU/ml. The positive rates of IgG antibody against measles virus in umbilical cord blood of neonates born to women aged ≤20, 21-25, 26-30, 31-35, and ≥36 years old were 91.07% (51/56), 90.27% (232/257), 89.54% (351/392), 88.12% (230/261), and 86.96% (80/92), respectively (χ 2=1.355, P=0.852). Multivariate logistic regression analysis showed that the positive rate of IgG antibody against measles virus in umbilical cord blood samples was higher in neonates with gestational age ≥37 weeks than in those with gestational age <37 weeks [OR (95%CI): 0.403 (0.262-0.622)]. Besides, the positive rate was also higher in newborns with a birth weight of 3.0-3.5 kg than in those with birth weight <3 kg or ≥3.5 kg [OR (95%CI): 0.868 (0.462-1.629), 1.765(1.087-2.865)]. Conclusions:The positive rate and the GMC of IgG antibody to measles virus in neonatal umbilical cord blood decrease with maternal age. It is recommended that women of childbearing age should receive supplementary immunization with measles-containing vaccine before pregnancy.

Objective:To evaluate the effect of controlled low central venous pressure with milrinone on laparoscopic hepatectomy in the patients.Methods:Fifty American Society of Anesthesiologists physical statusⅠ-Ⅲ patients of both sexes, aged 18-64 yr, with body mass index of 18-30 kg/m 2, of Child-Pugh grade A or B, undergoing elective laparoscopic hepatectomy, were divided into 2 groups ( n=25 each) using a random number table method: milrinone group (group M) and nitroglycerin group (group NG). After the start of surgery, milrinone 0.5 μg·kg -1·min -1 was continuously infused in group M, and nitroglycerin was continuously infused with the initial dose of 0.5 μg·kg -1·min -1 to maintain central venous pressure (CVP)≤5 mmHg in group NG.Mean arterial pressure and heart rate were recorded on admission to the operation room (T 0), at skin incision (T 1), at the beginning of liver resection (T 2), at completion of liver resection (T 3), at the end of operation (T 4), and CVP, cardiac index and stroke volume variation were recorded at T 1-4.Internal jugular vein blood samples were collected to determine the concentrations of hemogloblin, blood lactate at T 1 and T 4, and serum alanine aminotransferase, aspartate aminotransferase and creatinine concentrations at 1, 3 and 7 days after surgery.The score of blood oozing in hepatic surgical field, amount of norepinephrine used, blood loss, postoperative recovery and occurrence of complications within 7 days after operation were recorded. Results:Compared with group NG, cardiac index was significantly increased at T 2, 3, the CVP was decreased at T 2, the blood oozing score, blood loss, consumption of norepinephrine, and concentrations of blood lactate were decreased, and the postoperative drainage indwelling time was shortened in group M ( P<0.05). There was no significant difference in the serum alanine aminotransferase, aspartate aminotransferase and creatinine concentrations and incidence of postoperative complications at 1, 3 and 7 days after operation between the two groups ( P>0.05). Conclusions:Milrinone is better than nitroglycerin in decreasing central venous pressure, reducing blood loss, maintaining stable circulatory function and tissue perfusion in laparoscopic hepatectomy.

Objective:To investigate the epidemiological characteristics and etiological distribution of infection on 3 067 hospitalized pediatric patients with burns, and explore the prevention and treatment strategy of pediatric burns.Methods:A cross-sectional survey was conducted. An analysis was performed on the data of 3 067 hospitalized pediatric patients with burns who met the inclusion criteria and were admitted to the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from January 2012 to December 2020, including gender, age, causative factors, locations and severities of burns, seasons of accidents, and the type, source of tissue or body fluid, and drug resistance of pathogenic bacteria. API bacterial identification batten and automatic microbial identification system were applied for pathogen identification. Drug sensitivities of top 3 consistent ratio pathogen identifed were tested with minimum inhibitory concentration and disk diffusion method. WHONET 5.6 software was applied to analyze the data.Results:There were 3 067 hospitalized pediatric patients with burns, including 1 768 boys and 1 299 girls. The majority of pediatric burn patients were >1 and ≤4 years, accounting for 72.9% (2 236/3 067), and the minority of pediatric burn patients were >8 and ≤12 years, accounting for 4.9% (150/3 067). Moderate burns and severe burns of pediatric burn patients accounted for the majority parts, and the proportions of the two were close. The top cause of pediatric burns was scald, accounting for 81.6% (2504/3 067). Extremities were the most common burn sites in that of entire 3 254. The most pediatric burns occurred in winter, accounting for 29.4% (903/3 067). A total of 1 018 strains of pathogenic bacteria were collected from pediatric burn patients, all of which were non-repeated isolates. The pathogens with top five consistent ratio were Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae, and Escherichia coli, among which Staphylococcus aureus ranked the first every year. The pathogens were mainly isolated from the wound exudate, accounting for 81.34% (828/1 018). Staphylococcus aureus from 2012 to 2020 showed no resistance to vancomycin, linezolid or teicoplanin while Staphylococcus aureus isolated in 2019 was 100% resistant to macrolides, penicillin, aminoglycosides, and quinolones. Pseudomonas aeruginosa was not resistant to polymyxin B. Acinetobacter baumannii showed a high rate of drug resistance to most antibiotics. Conclusions:Among the pediatric burn patients admitted to the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from 2012 to 2020, the majority are male children aged >1 and ≤4 years with moderate burns. Scalds are the leading cause; and extremities are the common burn sites; and the most pediatric burns occurre in winter. Staphylococcus aureus from wound exudate is the primary pathogen of burn wound infections in pediatric patients.

Objective: To analyze the distribution and drug resistance of pathogens isolated from patients with catheter-related bloodstream infection (CRBSI) in burn intensive care unit (BICU). Methods: From January 2011 to December 2018, among 2 264 patients who were peripherally inserted central venous catheter at the BICU of the First Affiliated Hospital of Army Medical University (the third Military Medical University), hereinafter referred to as the author′s unit, 159 patients were diagnosed CRBSI, including 131 males and 28 females, aged 43 (1, 79) years. The pathogens primarily isolated from peripheral venous blood and central venous catheter blood/anterior central venous catheter specimen of patients with CRBSI were retrospectively analyzed. API bacteria identification kits and automatic microorganism identification instrument were used to identify pathogens. Broth micro-dilution method or Kirby-Bauer paper disk diffusion method was used to detect the drug resistance of the pathogens to 5 antifungal drugs including fluconazole and itraconazole, etc., and 37 antibacterial drugs including tigecycline and imipenem, etc. Modified Hodge test was used to further identify imipenem- and meropenem-resistant Klebsiella pneumonia. D test was used to detect erythromycin-induced clindamycin resistant Staphylococcus aureus. The WHONET 5.6 software was applied to analyze the annual incidence of CRBSI, mortality of patients with CRBSI, incidence of CRBSI cases, distribution of infection site, and duration of catheterization, detection of Gram-negative and Gram-positive bacteria, fungi, methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-sensitive Staphylococcus aureus (MSSA), and drug resistance of fungi and major Gram-negative and Gram-positive bacteria to the commonly used antibiotics in clinic. Results: (1) The incidence of CRBSI was 7.0% (159/2 264) during the eight years, which was slightly higher in 2014 and 2017 with 13.6% (30/221) and 11.1% (24/217) respectively. The mortality rate of patients with CRBSI was 7.5% (12/159). (2) The incidence of CRBSI cases was 14.9% (338/2 264); the main infection site was femoral vein, totally 271 cases (80.2%), and the duration of catheterization of this site was 9 (2, 25) d. (3) During the eight years, totally 543 strains of pathogens were isolated, including 353 (65.0%) strains of Gram-negative bacteria, 140 (25.8%) strains of Gram-positive bacteria, and 50 (9.2%) strains of fungi. The top three isolated pathogens with isolation rate from high to low were Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa, accounting for 23.2% (126/543), 17.1% (93/543), and 15.7% (85/543), respectively. Fungi were mainly Candida parapsilosis. Among the Staphylococcus aureus, the detection rate of MRSA was 98.9% (92/93), and that of MSSA was 1.1% (1/93). (4) Except for the low drug resistance rates to polymyxin B, minocycline, and tigecycline, the drug resistance rates of Acinetobacter baumannii to the other antibiotics were considerably high (80.1%-100.0%). Pseudomonas aeruginosa was not resistant to polymyxin B but highly resistant to netilmicin (88.7%) and piperacillin (92.6%), with resistance rates to the other antibiotics from 34.5% to 62.7%. Klebsiella pneumoniae was not resistant to tigecycline and lowly resistant to imipenem and meropenem (28.9%, 9 imipenem- and meropenem-resistant strains were further confirmed by modified Hodge test), with resistance rates to the other antibiotics from 40.9% to 95.2%. The resistance rates of MRSA to most antibiotics were higher than those of MSSA. MRSA was not resistant to linezolid, vancomycin, teicoplanin, sulfamethoxazole, or tigecycline. The resistance rates of MRSA to clindamycin and erythromycin were 7.9% and 62.0%, respectively, and those to the other antibiotics were higher than 91.5%. Except for the complete resistance to penicillin G and tetracycline, MSSA was not resistant to the other antibiotics. Thirty-three strains of Staphylococcus aureus showed resistance to erythromycin-induced clindamycin. Fungi was not resistant to amphotericin B, with drug resistance rates to voriconazole, itraconazole, ketoconazole, and fluconazole from 4.2% to 6.2%. Conclusions The incidence of CRBSI and mortality of patients with CRBSI are high in BICU of the author′s unit, and the main infection site is femoral vein. There are various types of pathogens in patients with CRBSI, and most of them are Gram-negative. The top three isolated pathogens are Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa, accompanying with grim drug resistance phenomenon.

Objective: To retrospectively analyze the diagnosis time, pathogen distribution, and drug resistance of fungal bloodstream infection in severe burn patients. Methods: Blood samples were collected from 55 severe burn patients with fungal bloodstream infection (including 46 males and 9 females, aged 42 (1, 78) years) admitted to the intensive care unit of the Institute of Burn Research of the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from July 2011 to May 2019 for retrospective analysis. Microbial monitoring system was used to cultivate pathogens, API yeast identification kit and Candida chromogenic medium were used to identify pathogens, and Kirby-Bauer paper disk diffusion method was used to detect drug resistance of fungi to fluconazole, amphotericin B, itraconazole, ketoconazole, and voriconazole. The positive rate of blood fungal culture, mortality rate, distribution of local fungal proliferation sites, the diagnosis time distribution of fungal bloodstream infection, the distribution of fungal species, resistance to commonly-used antifungal drugs, and the use of antibiotics were assessed. The WHONET 5.6 software was applied to analyze the distribution and drug resistance of fungi. Results: (1) Totally 4 839 blood samples were collected during the 9 years, and 122 strains of fungi were isolated, with positive rate of 2.52%. The mortality rate was 14.55% (8 patients) in 55 patients. Catheter fungal proliferation ranked the first among 30 cases of local fungal proliferation. (2) The diagnosis time of fungal bloodstream infection mainly distributed in ≤1 week of hospitalization [32.73% (18/55)]. (3) Among the 55 strains of fungi detected, the detection rate of Candida parapsilosis ranked the first (21.82%, 12 strains), Candida glabrata was the second (18.18%, 10 strains), and Candida tropicalis was tied with Candida albicans in the third place (14.55%, 8 strains). All the detected fungi were sensitive to amphotericin B, and the resistance rates to voriconazole, fluconazole, itraconazole, and ketoconazole were between 4.5% and 9.1%. (4) Droad-spectrum antibiotics were used in all the 55 patients, ≥3 kinds of antibiotics were used in 44 patients, and 37 patients used antibacterial drugs ≥7 days. Conclusions The diagnosis time of fungal bloodstream infection in the 55 severe burn patients was mainly within 1 week of hospitalization. Candida parapsilosis is the most commonly detected fungal species. Catheter fungal proliferation occurs most commonly among the 30 patients with local fungal proliferation. All the detected fungi were sensitive to amphotericin B, with low drug resistance to voriconazole, fluconazole, itraconazole, and ketoconazole. Broad-spectrum antibiotics were overused in the severe burn patients with fungal bloodstream infection.

The burn microbiology laboratory of the author′s unit is a level Ⅱ biosafety laboratory, which is mainly responsible for handling clinical microbial samples from our department and other departments in the hospital. Since the outbreak of the coronavirus disease 2019, in order to ensure the normal operation of routine work and the safety of medical staff, the microbiology laboratory has actively adjusted the daily work flow. The detailed work flow is summarized as follows to provide references for the safety protection of peer in clinical microbiology laboratory.