Differentiation between non-hypervascular pancreatic neuroendocrine tumour and pancreatic ductal adenocarcinoma on dynamic computed tomography and non-enhanced magnetic resonance imaging

Purpose: To determine the differentiating features between non-hypervascular pancreatic neuroendocrine tumour (PNET) and pancreatic ductal adenocarcinoma (PDAC) on dynamic computed tomography (CT) and non-enhanced magnetic resonance imaging (MRI). Material and methods: We enrolled 102 patients with non-hypervascular PNET (n = 15) or PDAC (n = 87), who had undergone dynamic CT and non-enhanced MRI. One radiologist evaluated all images, and the results were subjected to univariate and multivariate analyses. To investigate reproducibility, a second radiologist re-evaluated features that were significantly different between PNET and PDAC on multivariate analysis. Results: Tumour margin (well-defined or ill-defined) and enhancement ratio of tumour (ERT) showed significant differences in univariate and multivariate analyses. Multivariate analysis revealed a predominance of well-defined tumour margins in non-hypervascular PNET, with an odds ratio of 168.86 (95% confidence interval [CI]: 10.62-2685.29; p < 0.001). Furthermore, ERT was significantly lower in non-hypervascular PNET than in PDAC, with an odds ratio of 85.80 (95% CI: 2.57-2860.95; p = 0.01). Sensitivity, specificity, and accuracy were 86.7%, 96.6%, and 95.1%, respectively, when the tumour margin was used as the criteria. The values for ERT were 66.7%, 98.9%, and 94.1%, respectively. In reproducibility tests, both tumour margin and ERT showed substantial agreement (margin of tumour, κ = 0.6356; ERT, intraclass correlation coefficients (ICC) = 0.6155). Conclusions: Non-hypervascular PNET showed well-defined margins and lower ERT compared to PDAC, with significant differences. Our results showed that non-hypervascular PNET can be differentiated from PDAC via dynamic CT and non-enhanced MRI

Study of the lower thermospheric wind in the polar region using EISCAT data obtained in 2 solar cycles

第3回極域科学シンポジウム/第36回極域宙空圏シンポジウム 11月26日（月）、27日（火） 国立極地研究所 2階ラウン

青森県民の健康寿命アップ対策としての「心疾患10年リスク」の活用について(青森県の健康寿命アップと保健大学の取り組み, 第2回青森県立保健大学学術研究集会)

publisher青森市国立情報学研究所の「学術雑誌公開支援事業」により電子化されました

Modular Architecture of Bacterial RNase P Ribozymes as a Structural Platform for RNA Nanostructure Design

Ribonuclease P (RNase P) is a class of enzymes involved in the processing of precursor tRNAs to remove their 5'-leader sequences. Ribonuclease P enzymes are classified into two completely distinct classes, i.e. an RNA-based enzyme and a protein-only enzyme. The RNA-based enzyme functions as a ribozyme in which the catalytic machinery is supported by its RNA component consisting of a single RNA molecule. Bacterial RNase P RNAs are a classical class of ribozymes and their structures and catalytic mechanisms have been studied extensively. The bacterial RNase P ribozyme has a modular tertiary structure consisting of two large domains, each of which can self-fold without the partner domain. Such modular architecture, identification of which provided important insight into the function of this ribozyme, is attractive as a structural platform to design functional RNA nanostructures. The first section of this article briefly summarizes the diversity of RNase P mainly focusing on RNA-based enzymes. The second section describes the structures of bacterial RNase P ribozymes from the viewpoint of their application as modular tools in RNA nanostructure design. The last section summarizes the current state and next steps in modular engineering of RNase P RNAs, including possible design of RNase P ribozyme-based nanostructures

Rational Design of an Orthogonal Pair of Bimolecular RNase P Ribozymes through Heterologous Assembly of Their Modular Domains

The modular structural domains of multidomain RNA enzymes can often be dissected into separate domain RNAs and their noncovalent assembly can often reconstitute active enzymes. These properties are important to understand their basic characteristics and are useful for their application to RNA-based nanostructures. Bimolecular forms of bacterial RNase P ribozymes consisting of S-domain and C-domain RNAs are attractive as platforms for catalytic RNA nanostructures, but their S-domain/C-domain assembly was not optimized for this purpose. Through analysis and engineering of bimolecular forms of the two bacterial RNase P ribozymes, we constructed a chimeric ribozyme with improved catalytic ability and S-domain/C-domain assembly and developed a pair of bimolecular RNase P ribozymes the assembly of which was considerably orthogonal to each other