Erythritol attenuates postprandial blood glucose by inhibiting α-glucosidase

This work was supported by grants from Natural Science Foundation of Qinghai (No. 2016-ZJ-942Q), West Light Foundation of the Chinese Academy of Sciences (No. Y629071211), National Natural Science Foundation of China (No. 31701243), International Cooperative Projects of Qinghai province (No. 2017-HZ-811), Project of Discovery, Evaluation and Transformation of Active Natural Compounds, Strategic Biological Resources Service Network Program of Chinese Academy of Sciences (No. ZSTH-027), Major Special Science and Technology Projects in Qinghai Province (2014-GX-A3A-01).Diabetes mellitus (DM) is a serious metabolic disorder where impaired postprandial blood glucose regulation often leads to severe health complications. The natural chemical, erythritol is a C4 polyol approved by FDA for use as a sweetener. Here we examined a potential role for erythritol in the control of postprandial blood glucose levels in DM. An anti-postprandial hyperglycemia effect upon erythritol administration (500 mg kg-1) was demonstrated in alloxan-induced DM model mice by monitoring changes in blood glucose after intragastric administration of drugs and starch. We also found that erythritol most likely exerts its anti-postprandial hyperglycemic activities by inhibiting α-glucosidase in a competitive manner. This was supported by enzyme activity assays and molecular modelling experiments. In the latter experiments it was possible to successful dock erythritol into the catalytic pocket of α-glucosidase, with the resultant interaction likely to be driven by electrostatic interactions involving Asp 215, Asp69 and Arg446 residues. This study suggests that erythritol may not only serve as a glucose substitute but may also be a useful agent in the treatment of diabetes mellitus to help manage postprandial blood glucose levels.PostprintPeer reviewe

Optimizing Efficiency of Privacy-aware Search with Additive and Neural Ranking

Privacy considerations have become increasingly important for cloud-based information services. There are significant research challenges in top-k document search over outsourced large-scale datasets. It is because letting a cloud server access ranking features and perform advanced scoring computation may unsafely reveal privacy-sensitive information. With a practical restriction towards fast query response time, the heavy-weight cryptographic tools are often too expensive to deploy, and thus a server-hosted search system needs to seek optimized tradeoffs among privacy, efficiency, and relevance.In this dissertation, a series of efficiency optimized document retrieval solutions is proposed with additive ranking or neural ranking when privacy protection is considered. We firstly introduce an efficiency-enhancing design that obfuscates the access pattern of the inverted index data during query processing in a trusted execution environment (TEE). Then this dissertation presents our work on ORAM-based top-k document retrieval with additive ranking in a TEE, and discusses techniques to accelerate matching with window navigation based index pruning and path caching. Finally, we discuss a privacy-aware neural ranking method with analytic and experimental studies. This dissertation includes evaluation results with TREC datasets on the efficiency and relevance of our proposed schemes against multiple baselines

TAISAM: A Transistor Array-Based Test Method for Characterizing Heavy Ion-Induced Sensitive Areas in Semiconductor Materials

The heavy ion-induced sensitive area is an essential parameter for space application integrated circuits. Circuit Designers need it to evaluate and mitigate heavy ion-induced soft errors. However, it is hard to measure this parameter due to the lack of test structures and methods. In this paper, a test method called TAISAM was proposed to measure the heavy ion-induced sensitive area. TAISAM circuits were irradiated under the heavy ions. The measured sensitive areas are 1.75 μm2 and 1.00 μm2 with different LET values. TAISAM circuits are also used to investigate the layout structures that can affect the sensitive area. When the source region of the target transistor is floating, the heavy ion-induced sensitive area decreases by 28.5% for the target PMOS transistor while it increases by more than 28% for the target NMOS transistor. When the well contacts are added, the heavy ion-induced sensitive area decreases by more than 25% for the target PMOS transistor while it remains unchanged for the target NMOS transistor. Experimental results directly validate that the two structures significantly affect the heavy ion-induced sensitive area

Research on Resistor-Loaded Half-Ellipse Antenna System for GPR Application

A resistor-loaded half-ellipse antenna system mounted on a vehicle as a candidate for the exploration of the lunar subsurface is investigated. The antenna system includes two identical half-ellipse antennas, one is used for transmission, and the other is for reception. A resistive loading technique for broadening the bandwidth and improving impulse radiation is introduced. The performance of the proposed antenna with different height above ground surface is studied, and the influence of the vehicle on the antenna is analyzed. Then the antenna is manufactured and mounted on a vehicle as some tests are done. The simulated and measured antenna VSWR and radiation patterns are compared together, and good agreements between them are achieved

Ultraviolet B irradiation enhances the secretion of exosomes by human primary melanocytes and changes their exosomal miRNA profile.

OBJECTIVE:Melanocytes play a central role in skin homeostasis. In this study, we focus on the function of melanocyte releasing exosomes as well as exosomal microRNAs (miRNAs) and investigate whether ultraviolet B (UVB) irradiation exerts an impact on it. MATERIALS AND METHODS:Exosomes derived from human primary melanocytes were isolated through differential centrifugation and were identified in three ways, including transmission electron microscopy observation, nanoparticle tracking analysis, and Western blot analysis. Melanocytes were irradiated with UVB for the indicated time, and then melanin production and exosome secretion were measured. The exosomal miRNA expression profile of melanocytes were obtained by miRNA sequencing and confirmed by real-time PCR. RESULTS:Exosomes derived from human primary melanocytes were verified. UVB irradiation induced melanin production and increased the exosome release by the melanocytes. In total, 15 miRNAs showed higher levels in UVB-irradiated melanocyte-derived exosomes compared with non-irradiated ones, and the top three upregulated exosomal miRNAs were miR-4488, miR-320d, and miR-7704 (fold change > 4.0). CONCLUSION:It is verified for the first time that UVB irradiation enhanced the secretion of exosomes by melanocytes and changed their exosomal miRNA profile. This findings open a new direction for investigating the communication between melanocytes and other skin cells, and the connection between UVB and skin malignant initiation

TAISAM: A Transistor Array-Based Test Method for Characterizing Heavy Ion-Induced Sensitive Areas in Semiconductor Materials

The heavy ion-induced sensitive area is an essential parameter for space application integrated circuits. Circuit Designers need it to evaluate and mitigate heavy ion-induced soft errors. However, it is hard to measure this parameter due to the lack of test structures and methods. In this paper, a test method called TAISAM was proposed to measure the heavy ion-induced sensitive area. TAISAM circuits were irradiated under the heavy ions. The measured sensitive areas are 1.75 μm2 and 1.00 μm2 with different LET values. TAISAM circuits are also used to investigate the layout structures that can affect the sensitive area. When the source region of the target transistor is floating, the heavy ion-induced sensitive area decreases by 28.5% for the target PMOS transistor while it increases by more than 28% for the target NMOS transistor. When the well contacts are added, the heavy ion-induced sensitive area decreases by more than 25% for the target PMOS transistor while it remains unchanged for the target NMOS transistor. Experimental results directly validate that the two structures significantly affect the heavy ion-induced sensitive area