Construction and Verification of a Linear-rotary Microstage with a Millimeter-scale Range

Yuxin Peng,So Ito,Yasumasa Sakurai,Yuki Shimizu,Wei Gao 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

This paper presents a second-generation linear-rotary (Z-θZ) micro-stage driven by impact friction. The micro-stage was constructed by miniaturizing a previously developed linear-rotary stage. The moving element of the micro-stage, which was a steel cylinder, could be actuated along and around the Z-axis in millimeter-scale range. The steel cylinder was supported by two driving units. Each unit consisted of a permanent magnet and two piezoelectric actuators (PZTs) for generating the impact friction motions in the Z- and θZdirections. The size of the micro-stage was made to be 11.0 mm (L) × 11.0 mm (W) × 5.7 mm (H). For enhancement of the stage velocity, the transfer function of the micro-stage with the voltage applied to the PZT as the input and the PZT displacement as the output, was established. An improved waveform of the input voltage was then obtained based on the established transfer function for getting a triangular-shaped PZT displacement, which was an ideal waveform for the impact friction motion. The characteristics of the stage velocity before and after the improvement of the input voltage were verified and the effectiveness of the improved input voltage for enhancement of the stage velocity was confirmed.

Repeat liver resection versus salvage liver transplant for recurrent hepatocellular carcinoma: A propensity score-adjusted and -matched comparison analysis

Yuxin Guo,Ek-Khoon Tan,Nicholas L. Syn,Thinesh-Lee Krishnamoorthy,Chee-Kiat Tan,Reina Lim,Ser-Yee Lee,Chung-Yip Chan,Peng-Chung Cheow,Alexander Y. F. Chung,Prema Raj Jeyaraj,Brian K. P. Goh 한국간담췌외과학회 2019 Annals of hepato-biliary-pancreatic surgery Vol.23 No.4

Backgrounds/Aims: Repeat liver resection (RLR) and salvage liver transplantation (SLT) are viable treatment options for recurrent hepatocellular carcinoma (HCC). With possibly superior survival outcomes than RLR, SLT is however, limited by liver graft availability and poses increased perioperative morbidity. In this study, we seek to compare the outcomes of RLR and SLT for patients with recurrent HCC. Methods: Between 1999 and 2018, 94 and 16 consecutive patients who underwent RLR and SLT respectively were identified. Further retrospective subgroup analysis was conducted, comparing 16 RLR with 16 SLT patients via propensity-score matching. Results: After propensity-score adjusted analyses, SLT demonstrated inferior short-term perioperative outcomes than RLR, with increased major morbidity (57.8% vs 5.4 %, p=0.0001), reoperations (39.1% vs 0, p<0.0001), renal insufficiency (30.1% vs 3%, p=0.0071), bleeding (19.8% vs 2.2%, p=0.0289), prolonged intensive care unit stay (median=4 vs 0 days, p<0.0001) and hospital stay (median= 19.8 vs 7.1days, p<0.001). However, SLT showed significantly lower recurrence rate (15.4% versus 70.3%, p=0.0005) and 5-year cumulative incidence of recurrences (19.4% versus 68.4%, p=0.005). Propensity-matched subgroup analysis showed concordant findings. Conclusions: While SLT offers potentially reduced risks of recurrence and trended towards improved long-term survival outcomes relative to RLR, it has poorer short-term perioperative outcomes. Patient selection is prudent amidst organ shortages to maximise allocated resources and optimise patient outcomes.

Outcomes of salvage liver transplant for recurrent hepatocellular carcinoma

Yuxin Guo,Ek-Khoon Tan,Thinesh-Lee Krishnamoorthy,Chee-Kiat Tan,Ban-Hock Tan,Thuan-Tong Tan,Ser-Yee Lee,Chung-Yip Chan,Peng-Chung Cheow,Alexander Y. F. Chung,Prema Raj Jeyaraj,Brian K. P. Goh 한국간담췌외과학회 2019 Annals of hepato-biliary-pancreatic surgery Vol.23 No.1

Backgrounds/Aims: Salvage liver transplantation (SLT) is a therapeutic strategy for recurrent hepatocellular carcinoma (HCC). However, it remains controversial with compromised survival outcomes and increased perioperative morbidity compared to primary liver transplant (PLT). In the present work, we describe our institution’s experience on SLT by comparing outcomes of SLT to PLT for HCCs. Methods: Retrospective analysis was conducted for 49 transplant patients from 2006-2017. A comparative analysis was carried out between 14 SLT patients and 35 PLT patients. Results: SLT patients demonstrated significantly shorter time to recurrence than PLT patients (median=5.5 versus 23 months, p<0.001) with a trend towards increased perioperative major morbidity (42.9% versus 37%, p=0.711), inferior 5-year overall survival (61% versus 75%, p=0.345) and inferior 5-year recurrence-free survival (57% versus 72%, p=0.263). However, overall survival from the point of primary resection over a 10-year period showed no statistical difference between the 2 groups (SLT=60% versus PLT=61%, p=0.685). Conclusions: SLT is a viable treatment strategy for HCCs. However, it exhibited poorer short-term perioperative and oncologic outcomes than PLT. SLT requires better patient selection with liver donor grafts for optimization of resource allocation in this era of organ shortage. Considering the worldwide shortages in liver grafts, it is hypothesized that optimization of a salvage transplant strategy may improve resource allocation and reap optimal patient outcomes.

Impedance modeling and stability analysis of modular multilevel converter considering frequency coupling characteristics

Kai Shi,Peng Lu,Yuxin Sun,Peifeng Xu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.8

In recent years, a series of studies concerning the oscillation of interconnected systems has shown that frequency coupling has important effects on the stability of the system. In this paper, a more accurate theoretical model considering the frequency coupling effects is adopted to derive the transmission process in vector control, phase lock loop, and proportional–resonant controller of the harmonic perturbation in the frequency domain. This model is used to further deepen the application of harmonic linearization modeling to impedance modeling. An integrated three-phase modular multilevel converter simulation model based on the PSCAD platform is built to verify the accuracy of the theoretical modeling through the frequency sweep method. The influence of related system parameters on sequence and coupling impedance is analyzed in detail. The generalized Nyquist criterion is used to study the importance of coupling impedance to the stability analysis of the system.

Sphingomonas abietis sp. nov., an Endophytic Bacterium Isolated from Korean Fir

Jiang Lingmin,Choe Hanna,Peng Yuxin,Jeon Doeun,Cho Donghyun,Jiang Yue,Lee Ju Huck,Kim Cha Young,Lee Jiyoung 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.10

PAMB 00755T , a bacterial strain, was isolated from Korean fir leaves. The strain exhibits yellow colonies and consists of Gram-negative, non-motile, short rods or ovoid-shaped cells. It displays optimal growth conditions at 20°C, 0% NaCl, and pH 6.0. Results of 16S rRNA gene-based phylogenetic analyses showed that strain PAMB 00755T was most closely related to Sphingomonas chungangi MAH-6T (97.7%) and Sphingomonas polyaromaticivorans B2-7T (97.4%), and ≤96.5% sequence similarity to other members of the genus Sphingomonas. The values of average nucleotide identity (79.9–81.3%), average amino acid identity (73.3–75.9%), and digital DNA–DNA hybridization (73.3– 75.9%) were significantly lower than the threshold values for species boundaries; these overall genome-related indexes (OGRI) analyses indicated that the strain represents a novel species. Genomic analysis revealed that the strain has a 4.4-Mbp genome encoding 4,083 functional genes, while the DNA G+C content of the whole genome is 66.1%. The genome of strain PAMB 00755T showed a putative carotenoid biosynthetic cluster responsible for its antioxidant activity. The respiratory quinone was identified as ubiquinone 10 (Q-10), while the major fatty acids in the profile were identified as C18:1ω7c and/or C18:1ω6c (summed feature 8). The major polar lipids of strain PAMB 00755T were diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, and phosphatidylcholine. Based on a comprehensive analysis of genomic, phenotypic, and chemotaxonomic characteristics, we proposed the name Sphingomonas abietis sp. nov. for this novel species, with PAMB 00755T as the type strain (= KCTC 92781T = GDMCC 1.3779T ).

Receding-Horizon <tex> $l_{2}{-}l_{\infty}$</tex> FIR Filter With Embedded Deadbeat Property

Ahn, Choon Ki,Shmaliy, Yuriy S.,Shi, Peng,Zhao, Yuxin IEEE 2017 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS PART 2 E Vol.64 No.2

<P>This brief proposes a new finite-impulse response (FIR) receding-horizon filter for discrete-time linear systems in state space. A solution has l(2)-l(infinity) performance with the embedded deadbeat property and is called the FIR l(2)-l(infinity) filter (FIRllF). Based on the linear matrix inequality (LMI) and linear matrix equality (LME) formulations, a sufficient condition is found such that the FIRllF ascertains the guaranteed l(2)-l(infinity) performance with the deadbeat property. Using this result, we further obtain a new LMI condition for the existence of the FIRllF without using the LME. Through a numerical example, the proposed FIRllF is shown to be more robust against unexpected uncertainties than the existing l(2)-l(infinity) filter.</P>

Genome-Based Insights into the Thermotolerant Adaptations of Neobacillus endophyticus BRMEA1T

Lingmin Jiang,Ho Le Han,Yuxin Peng,Doeun Jeon,Donghyun Cho,Cha Young Kim,Jiyoung Lee 한국식물병리학회 2023 식물병연구 Vol.29 No.3

The bacterium Neobacillus endophyticus BRMEA1T, isolated from the medicinal plant Selaginella involvens, known as its thermotolerant can grow at 50°C. To explore the genetic basis for its heat tolerance response and its potential for producing valuable natural compounds, the genomes of two thermotolerant and four mesophilic strains in the genus Neobacillus were analyzed using a bioinformatic software platform. The whole genome was annotated using RAST SEED and OrthVenn2, with a focus on identifying potential heattolerance- related genes. N. endophyticus BRMEA1T was found to possess more stress response genes compared to other mesophilic members of the genus, and it was the only strain that had genes for the synthesis of osmoregulated periplasmic glucans. This study sheds light on the potential value of N. endophyticus BRMEA1T, as it reveals the mechanism of heat resistance and the application of secondary metabolites produced by this bacterium through whole-genome sequencing and comparative analysis.

Structure and electrical properties of Pr6O11-doped CaCu3Ti4O12 NTC ceramics

Zuo Yang,Tian Jian,Tian Yuxin,Miao Guangtan,Fu Peng 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.3

The xPr6O11–(1 − x)CaCu3Ti4O12 (CCTO) ceramics with perovskite structure were prepared by the solid-state reaction method. The effects of Pr 6O11 addition on the microstructure and electrical properties of the CCTO ceramics were studied. The addition of Pr 6O11 promoted the sintering of CCTO ceramics, and the mean grain sizes increased gradually from 2.13 to 5.08 μm with increasing Pr 6O11 content. All the samples had noticeable negative temperature coefficient (NTC) effect, and both the grain and grain boundary effects contributed to their NTC characteristics. The thermistor characteristic parameter B25/75 decreased from 6883 to 5291 K as Pr 6O11 contents increased from 0.00 to 0.08. The analysis shows that the conductivity of Pr 6O11–CCTO ceramics arises mainly from the electron hopping transport mechanism. The GB resistances are noticeably higher than grain resistances at the same Pr 6O11 content. All the samples showed electrical relaxation behavior. The above observations indicate that the structures and electrical properties of CCTO ceramics can be attuned precisely by adjusting the Pr 6O11 concentration.