Nondestructive and active interrogation system for special nuclear material:proof of principle and initial results

Herein,we employ the threshold energy neutron analysis(TENA)technique to introduce the world's first active interrogation system to detect special nuclear materials(SNMs),including U-235 and Pu-239.The system utilizes a DD neutron generator based on inertial electrostatic confinement(IEC)to interrogate suspicious objects.To detect secondary neutrons produced during fission reactions induced in SNMs,a tensioned metastable fluid detector(TMFD)is employed.The current status of the system's development is reported in this paper,accompanied by the results from experiments conducted to detect 10 g of highly enriched uranium(HEU).Notably,the experimental findings demonstrate a distinct difference in the count rates of measurements with and without HEU.This difference in count rates surpasses two times the standard deviation,indicating a confidence level of more than 96% for identifying the presence of HEU.The paper presents and extensively discusses the proof-of-principle experimental results,along with the system's planned trajectory.

Serum anti-Helicobacter pylori antibody titer and its association with gastric nodularity,atrophy,and age:A cross-sectional study

AIM To clarify the role of serum anti-Helicobacter pylori(H. pylori) antibody titers in gastric cancer.METHODS In this cross-sectional study, the effect of patients' baseline characteristics and endoscopic findings on their serum antibody titers were assessed. We evaluated consecutive patients who underwent esophagogastroduodenoscopy and their first evaluation for H. pylori infection using a serum antibody test. We excluded patients with a history of eradication therapy. The participants were divided into four groups according to their E-plate serum antibody titer. Patients with serum antibody titers < 3, 3-9.9, 10-49.9, and ≥ 50 U/m L were classified into groups A, B, C, and D, respectively. RESULTS In total, 874 participants were analyzed with 70%, 16%, 8.7%, and 5.1% of them in the groups A, B, C, and D, respectively. Patients in group C were older than patients in groups A and B. Gastric open-type atrophy, intestinal metaplasia, enlarged folds, diffuse redness, and duodenal ulcers were associated with a high titer. Regular arrangements of collecting venules, fundic gland polyps, superficial gastritis, and gastroesophageal reflux disease were related to a low titer. Multivariate analysis revealed that nodularity(P = 0.0094), atrophy(P = 0.0076), and age 40-59 years(vs age ≥ 60 years, P = 0.0090) were correlated with a high serum antibody titer in H. pylori-infected patients. Intestinal metaplasia and atrophy were related to age ≥ 60 years in group C and D.CONCLUSION Serum antibody titer changes with age, reflects gastric mucosal inflammation, and is useful in predicting the risk of gastric cancer.

Kyoto classification in patients who developed multiple gastric carcinomas after Helicobacter pylori eradication

BACKGROUND Endoscopic Kyoto classification predicts gastric cancer risk;however,the score in the patients with primary gastric cancer after Helicobacter pylori(H.pylori)eradication therapy is unknown.AIM To elucidate the Kyoto classification score in patients with both single gastric cancer and multiple gastric cancers developed after H.pylori eradication.METHODS The endoscopist recorded the Kyoto classification at the endoscope and the Kyoto classification score at the time of the first diagnosis of gastric cancer after H.pylori eradication.The score was compared between single gastric cancer group and multiple gastric cancers group.RESULTS The Kyoto score at the time of diagnosis of 45 cases of gastric cancer after H.pylori eradication was 4.0 points in average.The score was 3.8 points in the single gastric cancer group,and 5.1 points in the multiple gastric cancers group.The multiple group had a significantly higher score than the single group(P=0.016).In the multiple gastric cancers group,all the patients(7/7)had 5 or higher Kyoto score,while in single gastric cancer group,the proportion of patients with a score of 5 or higher was less than half,or 44.7%(17/38).CONCLUSION Patients diagnosed with gastric cancer after H.pylori eradication tended to have advanced gastritis.In particular,in cases of multiple gastric cancers developed after H.pylori eradication,the endoscopic Kyoto classification score tended to be 5 or higher in patients with an open type atrophic gastritis and the intestinal metaplasia extended to the corpus.

18^F-FDG PET/CT和体部背景信号抑制弥散加权全身成像对儿童神经母细胞瘤淋巴结和骨转移的诊断效能

目的近来许多研究表明，在无需暴露于电离辐射的情况下，全身＂体部背景信号抑制弥散加权成像＂（DWIBS）对儿童肿瘤具有更高探测灵敏度。该研究的目的是评价全身DWIBS和18F-脱氧葡萄糖（FDG） PET/CT显像对儿童神经母细胞瘤（NB）淋巴结和骨转移的诊断效能。方法该回顾性研究包括13例经病理学确诊为NB的患儿[男7例，女6例；平均年龄（2.9±2.0）岁]，均行18F-FDG PET/CT显像及全身DWIBS。评估每例患儿8处淋巴结区域和17处骨骼部位。患儿淋巴结转移和骨转移由123I-间碘苄胍（MIBG） SPECT/CT显像、骨SPECT显像及CT检查确定。由2位受过核医学培训的影像科医师分别对病灶18F-FDG的摄取和全身DWIBS中病灶的信号强度进行视觉分析，有意见分歧时讨论解决。18F-FDG PET/CT及全身DWIBS的诊断灵敏度、特异性和总体准确性采用McNemar检验进行分析。2种方法的阳性预测值（PPVs）和阴性预测值（NPVs）均采用Fisher确切概率法进行比较。结果13例患儿发生转移的淋巴结区域和骨骼部位分别为19和75处。18F-FDG PET/CT显像诊断儿童NB淋巴结转移的灵敏度、特异性、总体准确性、PPV和NPV分别为100%、98.7%、98.9%、95.0%和100%，诊断骨转移相应指标分别为90.7%、73.1%、80.3%、70.1%和91.9%。全身DWIBS诊断淋巴结转移的上述指标分别为94.7%、85.3%、87.2%、62.1%和98.5%，诊断骨转移相应指标分别为94.7%、24.0%、53.0%、46.4%和86.7%。全身DWIBS诊断骨转移的特异性、准确性和PPV均较低，其原因是假阳性率高（75.9%，82/108）。虽然2种方法在诊断淋巴结转移上的差异低于诊断骨转移的差异，但在诊断淋巴结转移上，全身DWIBS的特异性、准确性和PPV仍明显低于18F-FDG PET/CT。结论全身DWIBS的特异性、准确性和PPV明显低于18F-FDG PET/CT，其原因是假阳性的发生率高，尤其是在诊断骨转移方面。然而在诊断淋巴结转移及骨转移上，2种方法的灵敏度相似。全身DWIBS在诊断骨转移方面有较高的假阳性率，因此在儿童肿瘤分期中应谨慎使用。