1.Determination of Platinum Group Elements by Neutron Activation Analysis and Inductively Coupled Plasma-Mass Spectroscopy Combined with Fire Assay Preconcentration
Chunsheng LI ; Zhifang CHAI ; Xueying MAO ; Hong OUYANG ; Xiaolin LI
Chinese Journal of Analytical Chemistry 2001;29(5):534-537
Two methods for the determination of platinum group elements were established based on neutron activation analysis (NAA) and inductively coupled plasma mass spectroscopy (ICP-MS) combined with fire assay preconcentration. Their analytical sensitivity,accuracy and applicability were discussed.The detection limits (ng/g)of NAA for Ru,Rh,Pd,Os,Ir and Pt are 0.5,0.5,0.3,0.1,0.01 and 0.2,respectively.whereas those of ICP-MS are 0.1 for Ru,0.05 for Rh,0.1 for Ir and 0.1 for Pt. Thus, both are complimentary for determination of platinum group elements. By the established methods the contents of platinum group elements in five geological reference materials were determined.
2.Research progress of deep learning in nuclear myocardial perfusion imaging
Hao SONG ; Zhifang WU ; Xiangfei CHAI ; Rui XI ; Hao GE ; Sijin LI
Chinese Journal of Nuclear Medicine and Molecular Imaging 2024;44(2):116-119
In recent years, artificial intelligence (AI) technology represented by deep learning (DL) has developed rapidly, and smart medical care has become one of the most important application areas of AI. As the most accurate noninvasive test to assess myocardial blood flow, myocardial perfusion imaging (MPI) has important clinical values. At present, the use of DL algorithms to establish learning models for MPI images is still in the research stage, and more external verification and iterative updates are needed before it can be widely used in real time clinical practice. In this article, the application of DL algorithms in MPI is comprehensively elaborated to provide a basis and direction for further research.
3.Relationship between serum IGF-1 and resistin levels and osteoporosis in patients with type 2 diabetes mellitus
Fan GUO ; Zhibo GUO ; Chunyan CHAI ; Danyang LIU ; Zhifang JIANG
Journal of Public Health and Preventive Medicine 2025;36(4):110-113
Objective To study the relationship between serum insulin-like growth factor-1 (IGF-1) and resistin levels and osteoporosis in patients with type 2 diabetes mellitus (T2DM). Methods This study was conducted on 306 T2DM patients admitted to Baoding No.2 Central Hospital from January 2018 to January 2022. According to the detection results of bone mineral density, the patients were divided into osteoporosis group (T≤-2.5) and non-osteoporosis group (T>-2.5). The differences in IGF-1, resistin and bone mineral density were compared between the two groups. Pearson correlation analysis was used to analyze the correlation between serum IGF-1 and resistin levels and bone mineral density in patients with osteoporosis. Receiver operating characteristic (ROC) curve was applied to evaluate the application value of IGF-1 and resistin in predicting osteoporosis in patients with T2DM. Patients with T2DM complicated with osteoporosis were followed up for 2 years, and the occurrence of fractures was assessed. After univariate analysis, multivariate logistic regression analysis was applied to screen the risk factors for fractures in T2DM patients with osteoporosis. Results The incidence rate of osteoporosis in patients with T2DM was 53.59% (164/306). The IGF-1 level and bone mineral density level in the osteoporosis group were lower than those in the non-osteoporosis group, while the level of resistin was higher than that in the non-osteoporosis group (P<0.05). Serum IGF-1 in patients with osteoporosis was positively correlated with bone mineral density, and serum resistin was negatively correlated with bone mineral density (P<0.05). The AUC, sensitivity and specificity of combination of IGF-1 and resistin in predicting osteoporosis were 0.888, 82.93% and 62.68% respectively, which were all higher than those of single factor prediction (P<0.05). The 164 T2DM patients with osteoporosis were followed up for two years, and 15 patients developed fragility fractures, with the incidence of fracture of 9.15% (15/164). Multivariate analysis showed that hypoproteinemia, high-intensity exercise, lack of nutritional management, low IGF-1, and high resistin were risk factors for fractures in patients with T2DM complicated with osteoporosis (P<0.05). Conclusion For patients with T2DM, the incidence rates of osteoporosis and fractures are high. The levels of IGF-1 and resistin are closely related to bone mineral density, which can be combined to predict osteoporosis. Hypoproteinemia, high-intensity exercise, lack of nutritional management, low IGF-1 and high resistin are risk factors for fractures in T2DM patients with osteoporosis. It is necessary to carry out targeted preventive measures in clinical practice to reduce the incidence rate of fractures.