Concurrent Backscatter Streaming from Batteryless and Wireless Sensor Tags with Multiple Subcarrier Multiple Access

This paper proposes a novel multiple access method that enables concurrent sensor data streaming from multiple batteryless, wireless sensor tags. The access method is a pseudo-FDMA scheme based on the subcarrier backscatter communication principle, which is widely employed in passive RFID and radar systems. Concurrency is realized by assigning a dedicated subcarrier to each sensor tag and letting all sensor tags backscatter simultaneously. Because of the nature of the subcarrier, which is produced by constant rate switching of antenna impedance without any channel filter in the sensor tag, the tag-to-reader link always exhibits harmonics. Thus, it is important to reject harmonics when concurrent data streaming is required. This paper proposes a harmonics rejecting receiver to allow simultaneous multiple subcarrier usage. This paper particularly focuses on analog sensor data streaming which minimizes the functional requirements on the sensor tag and frequency bandwidth. The harmonics rejection receiver is realized by carefully handling group delay and phase delay of the subcarrier envelope and the carrier signal to accurately produce replica of the harmonics by introducing Hilbert and inverse Hilbert transformations. A numerical simulator with Simulink and a hardware implementation with USRP and LabVIEW have been developed. Simulations and experiments reveal that even if the CIR before harmonics rejection is 0dB, the proposed receiver recovers the original sensor data with over 0.98 cross-correlation

circRNA : A New Biomarker and Therapeutic Target for Esophageal Cancer

Circular RNAs (circRNAs) comprise a large class of endogenous non-coding RNA with covalently closed loops and have independent functions as linear transcripts transcribed from identical genes. circRNAs are generated by a “back-splicing” process regulated by regulatory elements in cis and associating proteins in trans. Many studies have shown that circRNAs play important roles in multiple processes, including splicing, transcription, chromatin modification, miRNA sponges, and protein decoys. circRNAs are highly stable because of their closed ring structure, which prevents them from degradation by exonucleases, and are more abundant in terminally differentiated cells, such as brains. Recently, it was demonstrated that numerous circRNAs are differentially expressed in cancer cells, and their dysfunction is involved in tumorigenesis and metastasis. However, the crucial functions of these circRNAs and the dysregulation of circRNAs in cancer are still unknown. In this review, we summarize the recent reports on the biogenesis and biology of circRNAs and then catalog the advances in using circRNAs as biomarkers and therapeutic targets for cancer therapy, particularly esophageal cancer

Comparison between Two Assessment Tests for Oral Hygiene : Adenosine Triphosphate + Adenosine Monophosphate Swab Test and Bacteria Number Counting by Dielectrophoretic Impedance Measurement

Objective assessments of oral hygiene are important to prevent oral and systemic diseases. Two objective assessment tests are available to assess oral hygiene; (1) the adenosine triphosphate (ATP) + adenosine monophosphate (AMP) swab test, which incorporates a luciferase assay and (2) a bacteria count using the dielectrophoretic impedance measurement (DEPIM) method. In this study, we compared the two tests using a subjective visual assessment by professional clinicians and investigated the clinical significance of these tests. Twenty-seven young participants (mean age 26.3 ± 3.2 years) and twenty-seven older participants (mean age 75.1 ± 5.9 years) were recruited. Oral bacteria were sampled from three areas, including the tongue dorsum, the buccal mucosa, and the faucal mucosa, and saliva was obtained using a cotton swab. The amount of ATP + AMP and the number of bacteria were measured by each specific apparatus. Additionally, one examiner assessed the overall condition of oral hygiene using the visual analog scale (VAS). In the ATP + AMP swab test, the means were highest in saliva. For the bacteria count, the means were higher in the tongue dorsum and saliva and lower in the faucal and buccal mucosa. The results of the subjective assessment of oral hygiene indicated that the VAS-value was 3.78 ± 0.97 for the young group and 3.35 ± 0.81 for the older group. No significant difference was observed between the two groups. Additionally, no significant relationship between the values of the ATP + AMP swab test and the bacteria count was found for any of the four sample sites. In the older group, the subjective assessment of oral hygiene was significantly correlated with the values of the ATP + AMP swab test (multiple correlation coefficient = 0.723, p = 0.002). In conclusion, the values provided by the ATP + AMP swab test were not always correlated to the bacteria count. The results of this study suggest that the subjective assessment of oral hygiene was more highly correlated with the results of the ATP + AMP swab test, as compared to the bacterial count assay

Application of artificial intelligence in the dental field : A literature review

Purpose: The purpose of this study was to comprehensively review the literature regarding the application of artificial intelligence (AI) in the dental field, focusing on the evaluation criteria and architecture types. Study selection: Electronic databases (PubMed, Cochrane Library, Scopus) were searched. Full-text articles describing the clinical application of AI for the detection, diagnosis, and treatment of lesions and the AI method/architecture were included. Results: The primary search presented 422 studies from 1996 to 2019, and 58 studies were finally selected. Regarding the year of publication, the oldest study, which was reported in 1996, focused on “oral and maxillofacial surgery.” Machine-learning architectures were employed in the selected studies, while approximately half of them (29/58) employed neural networks. Regarding the evaluation criteria, eight studies compared the results obtained by AI with the diagnoses formulated by dentists, while several studies compared two or more architectures in terms of performance. The following parameters were employed for evaluating the AI performance: accuracy, sensitivity, specificity, mean absolute error, root mean squared error, and area under the receiver operating characteristic curve. Conclusion: Application of AI in the dental field has progressed; however, the criteria for evaluating the efficacy of AI have not been clarified. It is necessary to obtain better quality data for machine learning to achieve the effective diagnosis of lesions and suitable treatment planning

Differences in the Composition of Activated Partial Thromboplastin Time (APTT) Reagents Affect Clot Waveform Analysis

Background Clot waveform analysis (CWA) based on activated partial thromboplastin time (APTT) is a useful assay for hemostasis. However, the effects of activators and phospholipid conditions on CWA have not been adequately investigated. Therefore, we characterized CWA using four different APTT reagents. Methods: We used 39 archived plasma samples from patients with hemophilia A (HA), 16 samples from patients with HA under emicizumab treatment, and 10 samples from healthy individuals for CWA with four different types of APTT reagents (reagents A, B, C, and D). We then compared Ad|min1|, Ad|min2|, and Ad|max2| from the CWA, which reflect the maximum velocity, maximum acceleration, and maximum deceleration, respectively, among the four reagents. Results: Similar clot waveform shapes were observed for each reagent in the healthy donor group, HA group, and HA under emicizumab group, and the waveform was different for each target group. Significant changes were found in clotting time (CT) (s), Ad|min1| (%/s), Ad|min2| (%/s2), and Ad|max2| (%/s2). The waveform pattern for the coagulation reaction by reagent D, comprising silica and synthetic phospholipids, was the fastest among the reagents examined. Further, the difference in Ad|min1| (%/s) and Ad|min2| (%/s2) was larger than that in CT depending on the reagent used(s), indicating that the measured value of CWA was affected by the reagent composition. Conclusion: Our results showed a significant difference among reagents with varying composition and concentration; this was found to affect the parameters obtained from CWA. Thus, the differences between reagents hinder standardization of quantitative evaluation using these parameters; further, this highlights the necessity of understanding the characteristics of APTT reagents and determining the reference range in individual facilities

二置換ベンゼン異性体の構造物性相関と新規水溶性向上策の提案

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 橋本 祐一, 東京大学教授 井上 将行, 東京大学教授 内山 真伸, 東京大学准教授 花岡 健二郎, 東京大学准教授 石川 稔University of Tokyo(東京大学

Reliability of Screening Methods to Diagnose Oral Dryness and Evaluate Saliva Secretion

In this study, we evaluated the reliability and reproducibility of widely implemented salivary flow rate and oral dryness tests. In experiment 1, twenty young and healthy Japanese participants volunteered to participate. For each participant, the oral moisture (OM) level, unstimulated whole saliva volume (U-WSV), and stimulated whole saliva volume (S-WSV) were measured at the same time on two separate days. In experiment 2, twenty-seven patients who were over 65 years of age volunteered to participate. The OM level and U-WSV were measured at the same time on two separate days. In Experiment 1, the intra-class correlation coefficients (ICCs) corresponding to the S-WSV, U-WSV, and OM level were 0.23, 0.28, and 0.16, respectively, for the young participants. In Experiment 2, the ICCs corresponding to the U-WSV/spitting and OM level were 0.83 and 0.12, respectively, for the older participants. The results of Bland–Altman analysis confirmed the absence of systematic error, with the exception of the OM level results in Experiment 2, which indicated systematic bias. In conclusion, we believe that there is currently no consistent and reliable screening test for assessing salivary flow rate and oral dryness, although the spitting test was determined to be highly reliable

ホテツ ソウチ ニヨル コジン ニンショウ システム ニ カンスル ブンケンテキ コウサツ

In disasters such as hydraulic bore, earthquakes and fire, the oral structure including the dental prostheses can provide identifying information. Over the years, many different personal identification system of dental prostheses have been reported. This present study analyzes the published literature offering the description of the personal identification system of dental prostheses. Two databases, “PubMed” and “Japana Centra Revuo Medicina” were searched to retrieve research papers referred to the personal identification system of dental prostheses. Twenty four papers were selected from the database with the criteria, and they were reviewed. 　This literature search showed that the personal identifications in three kinds of dental prostheses: removable denture, crown and implant were reported; and more papers on removable dentures were extracted compared to the crown and implant, however there is no high quality paper indicating that the structured methods for personal identification of dental prostheses is effective. 　A new method and common write format for personal identification are required to improve the present problems, and our systems using fluorescent material and ultraviolet light and femtosecond pulse laser-oriented recording system would be effective