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A Variational Model For Longitudinal Brain Tissue Segmentation
Mingjun Tang,Renwen Chen,Zijuan You 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.11
Longitudinal quantification of brain changes due to development, aging or disease plays an important role in the filed of personalized-medicine applications. However, due to the temporal variability in shape and different imaging equipment and parameters, estimating anatomical changes in longitudinal studies is significantly challenging. In this paper, a longitudinal Magnetic Resonance(MR) brain image segmentation algorithm proposed by combining intensity information and anisotropic smoothness term which contain a spatial smoothness constraint and longitudinal consistent constraint into a variational framework. The minimization of the proposed energy functional is strictly and effectively derived from a fast optimization algorithm. A large number of experimental results show that the proposed method can guarantee segmentation accuracy and longitudinal consistency in both simulated and real longitudinal MR brain images for analysis of anatomical changes over time.
Nano-scale study on molecular structure, thermal stability, and mechanical properties of geopolymer
Li Wei,Wang Yunkai,Yu Chunxiu,He Zijuan,Zuo Chuan,Yu Yang 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.2
The well thermal stability and mechanical properties of geopolymer can be attributed to its predominant adhesive constituent, sodium alumino-silicate hydrate (N-A-S-H). However, the intrinsic relation between molecular structure, stoichiometry, and performance of N-A-S-H is far from being understood. Herein, the structure, thermal stability, and tensile behavior of N-A-S-H at different Si/Al ratio are investigated by means of ReaxFF molecular dynamics. The results show that, after extreme low/high temperature treatment, the atomic configuration can also recover to a large extent. The hydrolysis during high temperature treatment slightly inhibits the structure recovery. Its expansion strain at elevated temperature is much smaller than that of calcium silicate hydrate, the primary component of Portland cement. Aluminum addition diminishes alumino-silicate skeleton’s connectivity and promotes the formation of energetically unstable Al–O–Al bonds, resulting in the drop of thermal stability and mechanical properties. The consistence between simulations and experiments demonstrates the considerable function of molecular structure of N-A-S-H for the macro-performance of geopolymer.
Liu Peilin,Wang Zhiqian,Jian Zijuan,Liu Xuan,Li Yanming,Yan Qun,Zhong Baiyun,Liao Mengting,Liang Xianghui,Liu Wenen 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.5
Nocardiosis is an uncommon opportunistic bacterial infection which becomes a significant health problem due to its increasing incidence and high mortality rate. However, many nocardiosis patients are underdiagnosed by physicians. To summarize the clinical characteristics and management of nocardiosis would help with better diagnosis and prognosis of nocardiosis. This retrospective study was conducted based on the medical records of nocardiosis patients between January 2015 and December 2021 in a tertiary hospital in China. Overall, 44 nocardiosis patients with 54 specimens were included. The patients consisted of 26 males and 18 females with a mean age of 50.4 ± 13.2 years. Among 44 patients, 26 (59.1%) were previously given immunosuppressive therapy. Connective tissue diseases (CTDs) were the most common underlying disease (16/44). The most frequent infection sites were the lungs (17/44) and skin or soft tissues (8/44). Common symptoms included cough (23/44), expectoration (18/44), fever (15/44), and subcutaneous abscesses (15/44). Forty-five out of 54 specimens (83.3%) required over 48 hours of culture time for nocardiosis detection. Thirty-six patients were cured or improved, 5 patients were discharged from the hospital due to poor prognosis, and 1 patient died. The average diagnosis time of poor prognosis cases was 19.7 days, which was significantly longer than those of improved or cured patients (7.3 days). Immunosuppressed patients comprise a large part of nocardiosis cases, which is worth attention in clinical practice. Early diagnosis, specifically through prolonged cultivation time of specimen, could help achieve better prognosis of nocardiosis patients.
Prognostic Value of Coronary Artery Calcium in a Multi-Ethnic Asian Cohort
Shu Yun Heng,Jien Sze Ho,Seyed Ehsan Saffari,Zijuan Huang,Foong Koon Cheah,Siang Jin Terrance Chua,Yung Jih Felix Keng,Lohendran Baskaran,Swee Yaw Tan 아시아심장혈관영상의학회 2021 Cardiovascular Imaging Asia Vol.5 No.3
Objective: Coronary artery calcium (CAC) is associated with the presence of coronary atherosclerotic plaque and is a prognostic factor of cardiovascular events. CAC varies among ethnic groups in patients of the same age and gender. Studies on the prognostic value of CAC in a multi-ethnic Asian population have yet to be performed. We aim to study the association of CAC and ethnicity, all-cause mortality, and acute myocardial infarction (AMI). Materials and Methods: This is a retrospective study with a multi-ethnic cohort aged 35–84 years from a single tertiary institution between 2007–2017. The individuals were all clinically referred for cardiac CT calcium scanning. CAC was determined by Toshiba Aquilion One 320 Multi-detector Row CT (Toshiba Medical System). Results: This study had 65% males at an average age of 55 years. In our multivariable analysis of 16561 individuals, CAC is generally higher in the Malay than Chinese ethnic group [odds ratio (OR)=1.30, 95% confidence interval (CI)=1.10–1.55] and did not differ among Indians and Chinese (p=0.400). Increasing CAC was associated with higher all-cause mortality (OR=1.27, 95% CI=1.17–1.36) and AMI (OR=1.50, 95% CI=1.35–1.66) after adjusting for known cardiovascular risk factors. Incorporation of CAC into a model with known cardiovascular risk variables enhanced prediction of all-cause mortality [area under the curve (AUC)=0.78] and AMI (AUC=0.85). Conclusion: This study is the largest performed in a multi-ethnic Asian cohort. Malay ethnicity seems to confer a higher likelihood of coronary calcification compared to the Chinese and Indians. CAC was associated with higher all-cause mortality and AMI and complemented traditional cardiovascular risk factors in risk prediction, confirming its applicability in a multi-ethnic Asian population.
Role of Dehydrocorybulbine in Neuropathic Pain After Spinal Cord Injury Mediated by P2X4 Receptor
Zhongwei Wang,Wei Mei,Qingde Wang,Rundong Guo,Peilin Liu,Yuqiang Wang,Zijuan Zhang,Limin Wang 한국분자세포생물학회 2019 Molecules and cells Vol.42 No.2
Chronic neuropathic pain is one of the primary causes of disability subsequent to spinal cord injury. Patients experiencing neuropathic pain after spinal cord injury suffer from poor quality of life, so complementary therapy is seriously needed. Dehydrocorybulbine is an alkaloid extracted from Corydalis yanhusuo. It effectively alleviates neuropathic pain. In the present study, we explored the effect of dehydrocorybulbine on neuropathic pain after spinal cord injury and delineated its possible mechanism. Experiments were performed in rats to evaluate the contribution of dehydrocorybulbine to P2X4 signaling in the modulation of pain-related behaviors and the levels of pronociceptive interleukins and proteins after spinal cord injury. In a rat contusion injury model, we confirmed that chronic neuropathic pain is present on day 7 after spinal cord injury and P2X4R expression is exacerbated after spinal cord injury. We also found that administration of dehydrocorybulbine by tail vein injection relieved pain behaviors in rat contusion injury models without affecting motor functions. The elevation in the levels of pronociceptive interleukins (IL-1β, IL-18, MMP-9) after spinal cord injury was mitigated by dehydrocorybulbine. Dehydrocorybulbine significantly mitigated the upregulation of P2X4 receptor and reduced ATP-evoked intracellular Ca2+ concentration. Both P2XR and dopamine receptor2 agonists antagonized dehydrocorybulbine’s antinociceptive effects. In conclusion, we propose that dehydrocorybulbine produces antinociceptive effects in spinal cord injury models by inhibiting P2X4R.