1.Influencing factors and clinical treatment of severe complications after unilateral pneumonectomy in treating tuberculous destroyed lung
Xiao LI ; Ning WANG ; Lei BAO ; Zhiqiang WU ; Gang LI ; Cong CAI ; Yijie SONG ; Dan LI ; Banggui WU ; Liangshuang JIANG ; Xiaojun YAO
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(05):626-633
Objective To evaluate the surgical efficacy of unilateral pneumonectomy for the treatment of tuberculous destroyed lung, analyze the causes of severe postoperative complications, and explore clinical management strategies. Methods A retrospective analysis was conducted on the clinical data of patients with tuberculous destroyed lung who underwent unilateral pneumonectomy at the Public Health Clinical Center of Chengdu from 2017 to 2023. Postoperative severe complications were statistically analyzed. Patients were divided into a non-severe complication group and a severe-complication group, and the causes, management, and outcomes of complications were analyzed. Results A total of 134 patients were included, comprising 69 males and 65 females, with a mean age of 17-73 (40.43±12.69) years. There were 93 patients undergoing left pneumonectomy and 41 patients undergoing right pneumonectomy. Preoperative sputum smear was positive in 35 patients, all of which converted to negative postoperatively. There were 58 patients with hemoptysis preoperatively, and none experienced hemoptysis postoperatively. Postoperative incisional infection occurred in 8 (5.97%) patients, and postoperative pulmonary infection in 26 (19.40%) patients. Severe postoperative complications occurred in 17 (12.69%) patients, including empyema in 9 (6.72%) patients, bronchopleural fistula with empyema in 1 (0.75%) patient, severe pneumonia in 3 (2.24%) patients, postpneumonectomy syndrome in 1 (0.75%) patient, chylothorax in 1 (0.75%) patient, ketoacidosis in 1 (0.75%) patient, and heart failure with severe pneumonia in 1 (0.75%) patient. Perioperative mortality occurred in 2 (1.49%) patients, both of whom underwent right pneumonectomy. Multivariate logistic regression analysis revealed that a history of ipsilateral thoracic surgery, concomitant Aspergillus infection, and greater blood loss were independent risk factors for severe complications following unilateral pneumonectomy for tuberculous destroyed lung (P<0.05). Conclusion Unilateral pneumonectomy for patients with tuberculous destroyed lung can significantly improve the clinical cure rate, sputum conversion rate, and hemoptysis cessation rate. However, there is a certain risk of severe perioperative complications and mortality, requiring thorough perioperative management and appropriate management of postoperative complications.
2.The PGAM5-NEK7 interaction is a therapeutic target for NLRP3 inflammasome activation in colitis.
Cheng-Long GAO ; Jinqian SONG ; Haojie WANG ; Qinghong SHANG ; Xin GUAN ; Gang XU ; Jiayang WU ; Dalei WU ; Yueqin ZHENG ; Xudong WU ; Feng ZHAO ; Xindong LIU ; Lei SHI ; Tao PANG
Acta Pharmaceutica Sinica B 2025;15(1):349-370
The innate immune sensor NLRP3 inflammasome overactivation is involved in the pathogenesis of ulcerative colitis. PGAM5 is a mitochondrial phosphatase involved in NLRP3 inflammasome activation in macrophages. However, the role of PGAM5 in ulcerative colitis and the mechanisms underlying PGAM5 regulating NLRP3 activity remain unknown. Here, we show that PGAM5 deficiency ameliorates dextran sodium sulfate (DSS)-induced colitis in mice via suppressing NLRP3 inflammasome activation. By combining APEX2-based proximity labeling focused on PGAM5 with quantitative proteomics, we identify NEK7 as the new binding partner of PGAM5 to promote NLRP3 inflammasome assembly and activation in a PGAM5 phosphatase activity-independent manner upon inflammasome induction. Interfering with PGAM5-NEK7 interaction by punicalagin inhibits the activation of the NLRP3 inflammasome in macrophages and ameliorates DSS-induced colitis in mice. Altogether, our data demonstrate the PGAM5-NEK7 interaction in macrophages for NLRP3 inflammasome activation and further provide a promising therapeutic strategy for ulcerative colitis by blocking the PGAM5-NEK7 interaction.
3.High expression of apolipoprotein C1 promotes proliferation and inhibits apoptosis of papillary thyroid carcinoma cells by activating the JAK2/STAT3 signaling pathway.
Yu BIN ; Ziwen LI ; Suwei ZUO ; Sinuo SUN ; Min LI ; Jiayin SONG ; Xu LIN ; Gang XUE ; Jingfang WU
Journal of Southern Medical University 2025;45(2):359-370
OBJECTIVES:
To investigate the expression of apolipoprotein C1 (APOC1) in papillary thyroid carcinoma (PTC) and its effects on proliferation and apoptosis of PTC cells.
METHODS:
The expression level of APOC1 in PTC and its impact on prognosis were analyzed using GEPIA 2 and Kaplan-Meier databases. Immunohistochemistry (IHC) and Western blotting were used to detect the expression of APOC1 in PTC and adjacent tissues and in 3 PTC cell lines and normal thyroid Nthyori 3-1 cells. In TPC-1 and BCPAP cells, the effect of Lipofectamine 2000-mediated transfection with APOC1 siRNA or an APOC1-overexpressing plasmid on cell growth and colony formation ability were examined by observing the growth curves and using colony-forming assay. The changes in cell cycle and apoptosis of the transfected cells were analyzed with flow cytometry. RT-qPCR and Western blotting were used to detect the changes in expressions of P21, P27, CDK4, cyclin D1, Bcl-2, Bax, caspase-3 and caspase-9 and the key proteins in the JAK2/STAT3 signaling pathway.
RESULTS:
APOC1 expression was significantly higher in PTC tissues and the 3 PTC cell lines than in the adjacent tissues and Nthyori 3-1 cells, respectively. In TPC-1 and BCPAP cells, APOC1 knockdown obviously reduced cell proliferative activity, increased the percentage of G0/G1 phase cells, lowered the percentages of S and G2 phase cells, promoted cell apoptosis, and downregulated mRNA and protein expression levels of CDK4, cyclin D1 and Bcl-2 and the protein levels of p-JAK2 and p-STAT3. APOC1 overexpression in the cells produced the opposite effects on cell proliferation, apoptosis, cell cycle and the mRNA and protein expressions. The application of AG490, a JAK2 inhibitor, strongly attenuated APOC1 overexpression-induced activation of the JAK2/STAT3 signaling pathway in BCPAP cells.
CONCLUSIONS
APOC1 overexpression promotes proliferation and inhibits apoptosis of PTC cells possibly by activating the JAK2/STAT3 signaling pathway and accelerating cell cycle progression.
Humans
;
Apoptosis
;
Cell Proliferation
;
STAT3 Transcription Factor/metabolism*
;
Signal Transduction
;
Janus Kinase 2/metabolism*
;
Thyroid Neoplasms/pathology*
;
Thyroid Cancer, Papillary
;
Cell Line, Tumor
;
Carcinoma, Papillary
4.Expert consensus on the diagnosis and treatment of cemental tear.
Ye LIANG ; Hongrui LIU ; Chengjia XIE ; Yang YU ; Jinlong SHAO ; Chunxu LV ; Wenyan KANG ; Fuhua YAN ; Yaping PAN ; Faming CHEN ; Yan XU ; Zuomin WANG ; Yao SUN ; Ang LI ; Lili CHEN ; Qingxian LUAN ; Chuanjiang ZHAO ; Zhengguo CAO ; Yi LIU ; Jiang SUN ; Zhongchen SONG ; Lei ZHAO ; Li LIN ; Peihui DING ; Weilian SUN ; Jun WANG ; Jiang LIN ; Guangxun ZHU ; Qi ZHANG ; Lijun LUO ; Jiayin DENG ; Yihuai PAN ; Jin ZHAO ; Aimei SONG ; Hongmei GUO ; Jin ZHANG ; Pingping CUI ; Song GE ; Rui ZHANG ; Xiuyun REN ; Shengbin HUANG ; Xi WEI ; Lihong QIU ; Jing DENG ; Keqing PAN ; Dandan MA ; Hongyu ZHAO ; Dong CHEN ; Liangjun ZHONG ; Gang DING ; Wu CHEN ; Quanchen XU ; Xiaoyu SUN ; Lingqian DU ; Ling LI ; Yijia WANG ; Xiaoyuan LI ; Qiang CHEN ; Hui WANG ; Zheng ZHANG ; Mengmeng LIU ; Chengfei ZHANG ; Xuedong ZHOU ; Shaohua GE
International Journal of Oral Science 2025;17(1):61-61
Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common dental issues, such as vertical root fracture, primary endodontic diseases, and periodontal diseases, as well as the low awareness of cemental tear for clinicians, misdiagnosis often occurs. The critical principle for cemental tear treatment is to remove torn fragments, and overlooking fragments leads to futile therapy, which could deteriorate the conditions of the affected teeth. Therefore, accurate diagnosis and subsequent appropriate interventions are vital for managing cemental tear. Novel diagnostic tools, including cone-beam computed tomography (CBCT), microscopes, and enamel matrix derivatives, have improved early detection and management, enhancing tooth retention. The implementation of standardized diagnostic criteria and treatment protocols, combined with improved clinical awareness among dental professionals, serves to mitigate risks of diagnostic errors and suboptimal therapeutic interventions. This expert consensus reviewed the epidemiology, pathogenesis, potential predisposing factors, clinical manifestations, diagnosis, differential diagnosis, treatment, and prognosis of cemental tear, aiming to provide a clinical guideline and facilitate clinicians to have a better understanding of cemental tear.
Humans
;
Dental Cementum/injuries*
;
Consensus
;
Diagnosis, Differential
;
Cone-Beam Computed Tomography
;
Tooth Fractures/therapy*
5.Targeting the chromatin structural changes of antitumor immunity
Li NIAN-NIAN ; Lun DENG-XING ; Gong NINGNING ; Meng GANG ; Du XIN-YING ; Wang HE ; Bao XIANGXIANG ; Li XIN-YANG ; Song JI-WU ; Hu KEWEI ; Li LALA ; Li SI-YING ; Liu WENBO ; Zhu WANPING ; Zhang YUNLONG ; Li JIKAI ; Yao TING ; Mou LEMING ; Han XIAOQING ; Hao FURONG ; Hu YONGCHENG ; Liu LIN ; Zhu HONGGUANG ; Wu YUYUN ; Liu BIN
Journal of Pharmaceutical Analysis 2024;14(4):460-482
Epigenomic imbalance drives abnormal transcriptional processes,promoting the onset and progression of cancer.Although defective gene regulation generally affects carcinogenesis and tumor suppression networks,tumor immunogenicity and immune cells involved in antitumor responses may also be affected by epigenomic changes,which may have significant implications for the development and application of epigenetic therapy,cancer immunotherapy,and their combinations.Herein,we focus on the impact of epigenetic regulation on tumor immune cell function and the role of key abnormal epigenetic processes,DNA methylation,histone post-translational modification,and chromatin structure in tumor immunogenicity,and introduce these epigenetic research methods.We emphasize the value of small-molecule inhibitors of epigenetic modulators in enhancing antitumor immune responses and discuss the challenges of developing treatment plans that combine epigenetic therapy and immuno-therapy through the complex interaction between cancer epigenetics and cancer immunology.
6.Arterial prophylactic occlusion technique in the application of surgery for locally advanced pancreatic cancer with arterial involvement after conversion therapy
Kailian ZHENG ; Xinyu LIU ; Xiaohan SHI ; Huan WANG ; Xiaoyi YIN ; Xinqian WU ; Lingyun GU ; Penghao LI ; Yikai LI ; Wei JING ; Shiwei GUO ; Bin SONG ; Suizhi GAO ; Gang JIN
Chinese Journal of Surgery 2024;62(10):938-946
Objective:To investigate and compare the clinical outcomes of the arterial pre-occlusion technique(APOT) and the traditional technique in the surgery of locally advanced pancreatic cancer with arterial involvement after conversion therapy.Methods:This is a retrospective cohort study. The clinical data of 145 patients with locally advanced pancreatic cancer with arterial involvement admitted to the Department of Hepato-Biliary-Pancreatic Surgery of the First Hospital Affiliated to Naval Medical University,from January 2020 to December 2022 were retrospectively analyzed. All patients completed neoadjuvant therapy for tumors, and the feasibility of radical surgical treatment was determined by a multidisciplinary collaborative team evaluation before surgery. According to whether the intraoperative artery was pre-occluded, 145 patients were divided into two groups, including 28 cases in the APOT group(16 males, 12 females, aged (59.0±9.4) years), and 117 cases in the routine surgery group(76 males, 41 females, aged (55.1±8.2) years). To ensure comparability of baseline data between the APOT group and the routine surgery group, a 1∶2 match was performed using the propensity score matching method, and the caliper value was 0.006 45. The t-test,the Mann-Whitney U test, χ2 test or Fisher′s exact test were used to compare the data between the two groups,respectively. Results:After matching the propensity score,there were 28 cases in the APOT group and 56 cases in the routine surgery group. There were no significant differences in gender,age,preoperative comorbidities,preoperative body mass index,surgical approaches,chemotherapy regimen,stereotactic body radiation therapy ratio,tumor markers,and type of invaded artery between the two groups (all P>0.05).The arterial occlusion time M(IQR) in the APOT group was 7.0(3.8)minutes(range:3 to 15 minutes),and no ischemic manifestations were observed in the distal target organs that blocked blood vessels after surgery. The operation time was (170.3±57.7)minutes in the APOT group and (235.0±80.2)minutes in the routine surgery group,and the difference was statistically significant ( t=-3.800, P<0.01). The APOT group also experienced less intraoperative blood loss(650(588)ml vs. 800(600)ml; U=1 026.500, P=0.021). No significant differences were found between the groups in combined vein resection and reconstruction,celiac trunk resection,early postoperative complications, readmission rates at 30 days,and postoperative length of stay(all P>0.05). Extra-arterial dissection was performed in all patients,with arterial resection and reconstruction in 3 cases: 2 cases in the APOT group(1 case involving the superior mesenteric artery and 1 case involving the common hepatic artery) and 1 case in the routine group(involving the common hepatic artery). Postoperative abdominal bleeding occurred in 4 cases,with 3 cases in the routine group,1 case in the routine group. The R0 resection rate was 85.7%(24/28) in the APOT group and 80.4%(45/56) in the routine group,without significant differences between the groups( P=0.763). The median overall survival time was 27.6 months for the APOT group and 22.5 months for the routine group,while the median disease-free survival was 11.7 months and 16.8 months,respectively,with no significant differences between the two groups( P=0.532, P=0.927). Conclusion:The arterial pre-occlusion technique can be used for extra-arterial dissection in patients with locally advanced pancreatic cancer involving the arteries,reducing surgery time and intraoperative blood loss.
7.Arterial prophylactic occlusion technique in the application of surgery for locally advanced pancreatic cancer with arterial involvement after conversion therapy
Kailian ZHENG ; Xinyu LIU ; Xiaohan SHI ; Huan WANG ; Xiaoyi YIN ; Xinqian WU ; Lingyun GU ; Penghao LI ; Yikai LI ; Wei JING ; Shiwei GUO ; Bin SONG ; Suizhi GAO ; Gang JIN
Chinese Journal of Surgery 2024;62(10):938-946
Objective:To investigate and compare the clinical outcomes of the arterial pre-occlusion technique(APOT) and the traditional technique in the surgery of locally advanced pancreatic cancer with arterial involvement after conversion therapy.Methods:This is a retrospective cohort study. The clinical data of 145 patients with locally advanced pancreatic cancer with arterial involvement admitted to the Department of Hepato-Biliary-Pancreatic Surgery of the First Hospital Affiliated to Naval Medical University,from January 2020 to December 2022 were retrospectively analyzed. All patients completed neoadjuvant therapy for tumors, and the feasibility of radical surgical treatment was determined by a multidisciplinary collaborative team evaluation before surgery. According to whether the intraoperative artery was pre-occluded, 145 patients were divided into two groups, including 28 cases in the APOT group(16 males, 12 females, aged (59.0±9.4) years), and 117 cases in the routine surgery group(76 males, 41 females, aged (55.1±8.2) years). To ensure comparability of baseline data between the APOT group and the routine surgery group, a 1∶2 match was performed using the propensity score matching method, and the caliper value was 0.006 45. The t-test,the Mann-Whitney U test, χ2 test or Fisher′s exact test were used to compare the data between the two groups,respectively. Results:After matching the propensity score,there were 28 cases in the APOT group and 56 cases in the routine surgery group. There were no significant differences in gender,age,preoperative comorbidities,preoperative body mass index,surgical approaches,chemotherapy regimen,stereotactic body radiation therapy ratio,tumor markers,and type of invaded artery between the two groups (all P>0.05).The arterial occlusion time M(IQR) in the APOT group was 7.0(3.8)minutes(range:3 to 15 minutes),and no ischemic manifestations were observed in the distal target organs that blocked blood vessels after surgery. The operation time was (170.3±57.7)minutes in the APOT group and (235.0±80.2)minutes in the routine surgery group,and the difference was statistically significant ( t=-3.800, P<0.01). The APOT group also experienced less intraoperative blood loss(650(588)ml vs. 800(600)ml; U=1 026.500, P=0.021). No significant differences were found between the groups in combined vein resection and reconstruction,celiac trunk resection,early postoperative complications, readmission rates at 30 days,and postoperative length of stay(all P>0.05). Extra-arterial dissection was performed in all patients,with arterial resection and reconstruction in 3 cases: 2 cases in the APOT group(1 case involving the superior mesenteric artery and 1 case involving the common hepatic artery) and 1 case in the routine group(involving the common hepatic artery). Postoperative abdominal bleeding occurred in 4 cases,with 3 cases in the routine group,1 case in the routine group. The R0 resection rate was 85.7%(24/28) in the APOT group and 80.4%(45/56) in the routine group,without significant differences between the groups( P=0.763). The median overall survival time was 27.6 months for the APOT group and 22.5 months for the routine group,while the median disease-free survival was 11.7 months and 16.8 months,respectively,with no significant differences between the two groups( P=0.532, P=0.927). Conclusion:The arterial pre-occlusion technique can be used for extra-arterial dissection in patients with locally advanced pancreatic cancer involving the arteries,reducing surgery time and intraoperative blood loss.
8.A multi-center epidemiological study on pneumococcal meningitis in children from 2019 to 2020
Cai-Yun WANG ; Hong-Mei XU ; Gang LIU ; Jing LIU ; Hui YU ; Bi-Quan CHEN ; Guo ZHENG ; Min SHU ; Li-Jun DU ; Zhi-Wei XU ; Li-Su HUANG ; Hai-Bo LI ; Dong WANG ; Song-Ting BAI ; Qing-Wen SHAN ; Chun-Hui ZHU ; Jian-Mei TIAN ; Jian-Hua HAO ; Ai-Wei LIN ; Dao-Jiong LIN ; Jin-Zhun WU ; Xin-Hua ZHANG ; Qing CAO ; Zhong-Bin TAO ; Yuan CHEN ; Guo-Long ZHU ; Ping XUE ; Zheng-Zhen TANG ; Xue-Wen SU ; Zheng-Hai QU ; Shi-Yong ZHAO ; Lin PANG ; Hui-Ling DENG ; Sai-Nan SHU ; Ying-Hu CHEN
Chinese Journal of Contemporary Pediatrics 2024;26(2):131-138
Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]
9.A novel nomogram-based model to predict the postoperative overall survival in patients with gastric and colorectal cancer
Siwen WANG ; Kangjing XU ; Xuejin GAO ; Tingting GAO ; Guangming SUN ; Yaqin XIAO ; Haoyang WANG ; Chenghao ZENG ; Deshuai SONG ; Yupeng ZHANG ; Lingli HUANG ; Bo LIAN ; Jianjiao CHEN ; Dong GUO ; Zhenyi JIA ; Yong WANG ; Fangyou GONG ; Junde ZHOU ; Zhigang XUE ; Zhida CHEN ; Gang LI ; Mengbin LI ; Wei ZHAO ; Yanbing ZHOU ; Huanlong QIN ; Xiaoting WU ; Kunhua WANG ; Qiang CHI ; Jianchun YU ; Yun TANG ; Guoli LI ; Li ZHANG ; Xinying WANG
Chinese Journal of Clinical Nutrition 2024;32(3):138-149
Objective:We aimed to develop a novel visualized model based on nomogram to predict postoperative overall survival.Methods:This was a multicenter, retrospective, observational cohort study, including participants with histologically confirmed gastric and colorectal cancer who underwent radical surgery from 11 medical centers in China from August 1, 2015 to June 30, 2018. Baseline characteristics, histopathological data and nutritional status, as assessed using Nutrition Risk Screening 2002 (NRS 2002) score and the scored Patient-Generated Subjective Global Assessment, were collected. The least absolute shrinkage and selection operator regression and Cox regression were used to identify variables to be included in the predictive model. Internal and external validations were performed.Results:There were 681 and 127 patients in the training and validation cohorts, respectively. A total of 188 deaths were observed over a median follow-up period of 59 (range: 58 to 60) months. Two independent predictors of NRS 2002 and Tumor-Node-Metastasis (TNM) stage were identified and incorporated into the prediction nomogram model together with the factor of age. The model's concordance index for 1-, 3- and 5-year overall survival was 0.696, 0.724, and 0.738 in the training cohort and 0.801, 0.812, and 0.793 in the validation cohort, respectively.Conclusions:In this study, a new nomogram prediction model based on NRS 2002 score was developed and validated for predicting the overall postoperative survival of patients with gastric colorectal cancer. This model has good differentiation, calibration and clinical practicability in predicting the long-term survival rate of patients with gastrointestinal cancer after radical surgery.
10.Preliminary testing and analysis of crosstalk in gross α and gross β measurement using an MPC 9604 low background α/β counter
Jiaang XU ; Gang SONG ; Hailiang LI ; Fangfang WU ; Chang JIN ; Nan MIN ; Xiaoshan WANG
Chinese Journal of Radiological Medicine and Protection 2024;44(11):965-970
Objective:To explore the causes of the crosstalk in the gross α and gross β measurement using an MPC 9604 low background α/β counter.Methods:With the A4 copy paper (70 g/m 2), polyethylene (PE) films (8.7 g/m 2), and 304 stainless steel seperately as shielding materials, the gross α and gross β experiments, gamma spectrometry experiments and solid state nuclear track detection (SSNTD) experiments were conducted by using 241Am and 40K standard materials. A comprehensive analysis encompassing statistical analysis and nuclear physics analysis was performed to reveal the impact of contributing factors on the crosstalk in the gross α and gross β measurement with an MPC 9604 low background α/β counter. Results:241Am powder source experimental result: when two sheets of copy paper were used in the experiment, α-rays did not generate one count in the β channel of the low background α/β counter. The same test with the shielding material of two layers of PE films showed that the α count rate further decreased by about 36.5%, while the β count rate hardly changed. The gross α and gross β experiments and γ spectrometry with the shielding material of stainless steel demonstrated that the characteristic γ ray peaking at 59.5 keV of the 241Am powder source did not generate one count in the β channel. 40K powder source experimental result: when the source was covered with steel of total thickness of 0.965 mm in the gross α and gross β experiments, the γ rays of 40K did not generate one count in the β channel. Compared with naked 40K powder source, when source was covered with one and two sheets of copy paper, the gross α count rate decreased approximately from 3.30 × 10 -3 to 1.50 × 10 -3 and 1.75 × 10 -3, respectively. The SSNTD indicated the presence of other α nuclides in 40K powder source. Conclusions:The β counting in the β channel with the 241Am powder source using MPC 9604 low background α/β counter was, instead of α-rays, caused by the internal conversion electrons and the characteristic X rays of 11.870-22.402 keV emitted from the 241Am powder source, thus this is not a true α/β crosstalk. The α counting in α channel with the 40K powder source, except the contribution of impurity α nuclides, was mainly attributed to the α signals arising from β particles when the amplitude of the piled-up β pules exceeded the discrimination threshold of the detector, therefore it is a true crosstalk.

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