Objective:To standardize the quantitation of 18F-Florbetapir PET SUV ratio (SUVR) to the Centiloid (CL) scale, and analyze the positive rate of β-amyloid (Aβ) in Chinese Preclinical Alzheimer′s Disease (AD) Study (C-PAS). Methods:11C-Pittsburgh compound B(PIB) and 18F-Florbetapir images from public databases " Standard PIB" and " Florbetapir Calibration" were preprocessed by statistical parametric mapping (SPM) 12, and the transformative formulas from SUVR to CL were derived. Then a total of 942 subjects (357 males, 585 females; age (66.4±8.1) years) from C-PAS who received 18F-Florbetapir PET at the Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University from October 2018 to August 2023 were retrospectively included. CL values were calculated and the Aβ positive rates (CL value≤12, Aβ negative; 12< CL value<30, Aβ subtle pathology; CL value≥30, Aβ positive) of AD, mild cognitive impairment (MCI) and cognitive unimpaired (CU) groups were explored. Data were analyzed by using Kruskal-Wallis rank sum test, Dunn′s test (Bonferroni correction ) and χ2 test. Results:The formula for the 18F-Florbetapir SUVR converted to CL was CL=179.64×SUVR_Florbetapir-186.95. In the C-PAS cohort, the SUVR, CL value, Aβ positive rate (including subtle pathology) of patients with clinically diagnosed AD were 1.29±0.22, 43.97±39.23, 71.80%(140/195), which were 1.04(1.02, 1.14), 1.16(-4.04, 17.14), 28.50%(61/214) for patients with MCI, and 1.04(1.01, 1.08), 0.54(-5.29, 7.69), 15.38%(82/533) for CU subjects, respectively. SUVR, CL value and the ratio of negative, subtle and positive Aβ pathology of the above three groups exhibited statistical differences ( H=148.30, H=148.30, χ2=262.12, all P<0.001). Besides, mixed MCI group exhibited higher CL values ((2.45(-1.54, 46.32) vs -1.58(-6.33, 7.20); H=8.21, P=0.016; z=2.81, P=0.015) and Aβ positive rate (including subtle pathology) (41.18%(14/34) vs 14.64%(6/41); χ2 values: 12.71 and 10.63, both P<0.01), compared to non-amnestic MCI group. The CL values and Aβ positive rates were also increased with age in CU group. Conclusion:This study validates the feasibility of the CL formula with 18F-Florbetapir images and reveals Aβ deposition in C-PAS cohort, which can lay the foundation for multi-center Aβ PET studies in China.

Objective:To construct a comprehensive and targeted risk assessment index system for central venous catheter (CVC) dysfunction in patients undergoing continuous renal replacement therapy (CRRT) .Methods:The risk assessment indicators for CVC dysfunction in CRRT patients were determined based on literature review and Delphi expert consultation. From July to September 2023, 19 experts in hemodialysis were selected for expert consultation. Based on expert opinions and screening criteria, corresponding indicators were added, deleted, or modified. After the second round of consultation, the expert opinions tended to be consistent.Results:A total of 17 experts completed two rounds of consultation. In the two rounds of consultation, the effective response rates of the questionnaires were 89.5% (17/19) and 100.0% (19/19), respectively, and the expert authority coefficients were 0.87 and 0.88, respectively. The Kendall harmony coefficients were 0.131 and 0.138 ( P<0.05). The final risk assessment index system included seven primary indicators and 44 secondary indicators. Conclusions:The risk assessment index system for CVC dysfunction in CRRT patients constructed is scientific, reliable, and practical, which can provide reference for clinical medical and nursing staff to improve catheter risk management in CRRT patients.

Presynaptic dopaminergic PET imaging is a useful method for the diagnosis of parkinsonism. Based on the expert consensus on operation and clinical application of dopamine transporter brain PET imaging technology published in 2020, this paper further recommends the relevant elements of result interpretation of presynaptic dopaminergic PET imaging.

Objective:To explore gene expression and metabolic capacity changes of brown adipose tissue(BAT)during different gestation periods.Methods:A normal pregnancy model was established using C57BL/6J mice, while infertile mice of the same age were served as the control group. The morphological alteration of BAT during pregnancy as well as the gene expression of uncoupling protein 1(UCP1) and other fat browning and mitochondrial marker genes were detected. Moreover, BATs from early and late gestation were selected to screen differentially expressed genes in relation to pregnancy progressing by RNA sequencing(RNA-seq), and gene ontology(GO) and Kyoto gene and gene sequencing(KEGG)were performed.Results:With pregnancy progressing, the size of BAT lipid droplets was substantially enlarged, UCP1 protein expression was decreased( P<0.01), and the fat browning marker genes(Ucp1, Dio2, and Pgc1α)and the mitochondrial marker gene CytC were downregulated( P<0.001). Additionally, a total of 1 298 distinct genes were identified by RNA-seq, 906 of which were upregulated and 392 were downregulated at later stage of pregnancy. GO and KEGG analyses revealed that the differentially expressed genes were mainly enriched in bioregulatory functional pathways such as lipid metabolism, sex steroid hormones, and inflammatory factors. Conclusion:BAT in mice showed larger lipid droplets and reduced thermogenic and metabolic capacity during late gestation, and BAT gene expression was significantly different in different periods of gestation, so reduced metabolic capacity of BAT may contribute to metabolic abnormality during pregnancy.

Due to the availability of 18F-FDG in PET centers, this article aims to advocate and promote the standardization of 18F-FDG PET brain imaging in dementia in order to improve the reliability, repeatability and comparison of the imaging process and results. It is also provided to guide the PET imaging operation standard and to give suggestions on image interpretation.

Background Organic ultraviolet (UV) filters are widely used in personal care products. So far, relevant studies on organic UV filters in indoor dust have been reported. Objective This study aims to establish a thermal desorption combined with gas chromatography-mass spectrometry (TD-GCMS) method to identify organic UV filters in indoor air collected from different indoor environments, so as to reveal the pollution levels and characteristics of organic UV filters in indoor environment. Methods Based on the standard indoor air sampling protocol, a total of 60 samples were collected from eight different kinds of indoor environments (male and female dormitory rooms, offices, labs, barber shops, printing shops, hotels, and private cars) on and nearby Minhang Campus of Shanghai Jiao Tong University from August to November, 2020. The concentrations of six common organic UV filters, including homosalate (HMS), 2-ethylhexyl salicylate (EHS), 3-(4-methylbenzylidene)-camphor (4-MBC), isoamyl 4-methoxycinnamate (IMC), octocrylene (OC), and octyl 4-methoxycinnamate (EHMC), in the air of different indoor environments were detected by TD-GCMS. Furthermore, the correlations of individual organic UV filters in different indoor environments were analysed. Results Under optimized detection conditions, the correlation coefficients of the quantitative standard curves of selected six organic UV filters were all at or above 0.997. The relative standard deviations of 1 mg·L⁻³ samples ranged from 1.74% to 7.11%, and the recoveries ranged from 67.17% to 106.5%. The relative standard deviations of 10 mg·L⁻³ samples ranged from 3.59% to 8.76%, and the recoveries ranged from 78.80% to 126.60%. The detection rates of the other five organic UV filters except IMC were all at or more than 92% in eight different kinds of indoor air. The median concentration of total organic UV filters was 75.17 ng·m⁻³, and EHS presented the highest median concentration of 28.55 ng·m⁻³. Regarding different indoor environments, the highest concentration of total organic UV filters was found in the female dormitory samples, 154.98 ng·m⁻³. The respective pair-analysis among HMS, EHMC, OC, and EHS of all indoor air samples reached a significant level of correlation (r=0.40-0.61, P<0.01). Conclusion The TD-GCMS method is satisfactory for the determination of organic UV filters in indoor air. EHS, EHMC, HMS, OC, and 4-MBC are identified in selected eight indoor environments, and they may have similar sources of pollution.