Enhanced Cold Wall CVD Reactor Growth of Horizontally Aligned Single-Walled Carbon Nanotubes

Wei Mu,곽은혜,Bingan Chen,Shirong Huang,Michael Edwards,Yifeng Fu,Kjell Jeppson,Kenneth Teo,정구환,Johan Liu 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.3

Synthesisof horizontally-aligned single-walled carbon nanotubes (HA-SWCNTs) bychemical vapor deposition (CVD) directly on quartz seems very promising for thefabrication of future nanoelectronic devices. In comparison to hot-wall CVD, synthesisof HA-SWCNTs in a cold-wall CVD chamber not only means shorter heating, coolingand growth periods, but also prevents contamination of the chamber. However, sincemost synthesis of HA-SWCNTs is performed in hot-wall reactors, adapting this wellestablishedprocess to a cold-wall chamber becomes extremely crucial. Here, in orderto transfer the CVD growth technology from a hot-wall to a cold-wall chamber, asystematic investigation has been conducted to determine the influence of processparameters on the HA-SWCNT’s growth. For two reasons, the cold-wall CVDchamber was upgraded with a top heater to complement the bottom substrate heater;the first reason to maintain a more uniform temperature profile during HA-SWCNTsgrowth, and the second reason to preheat the precursor gas flow before projecting itonto the catalyst. Our results show that the addition of a top heater had a significanteffect on the synthesis. Characterization of the CNTs shows that the average density ofHA-SWCNTs is around 1 - 2 tubes/μm with high growth quality as shown by Ramananalysis.

Enhanced p-type Conductivity of Nitrogen Doped ZnO by Nano/Micro Structured Rods and Zn-Rich Co-Doping Process

Wei Mu,Lei L. Kerr,David C. Look 대한금속·재료학회 2011 ELECTRONIC MATERIALS LETTERS Vol.7 No.2

We report the formation of p-type nitrogen doped ZnO (ZnO:N) grown by thermal-evaporation deposition. We found that the ZnO nano/micro structured rods can improve nitrogen doping. In addition, co-doping with metal (excess Zn in this study) can enhance nitrogen doping through a Zn-rich process. The effects of nitrogen precursors on the electrical and optical properties of ZnO:N were investigated. This study shows that growth process plays a critical role in the electrical properties of ZnO:N.

The Accumulation of Rare Earth Elements Fertilizer and its Subsequent Effects on Apple Fruit Quality at Harvest and During Storage

Wei-Wei Zheng(정위위),Mu-Young Park(박무용),Peter Hirst(피터 허스트),Tae-Myung Yoon(윤태명),Ik-Jo Chun(전익조) (사)한국생물환경조절학회 2012 생물환경조절학회지 Vol.21 No.4

본 연구는 희토류비료 시비가 8년생 ‘후지’/M.9 사과의 미량원소 변화 및 사과의 수확 품질과 5개월간 4 저장 후 과실 품질에 미치는 영향을 알아보기 위해 수행하였다. 1년차 희토류 비료의 시비는 ‘후지’ 사과 과실내 란타늄, 프라세오디뮴, 가돌리늄 및 네오디뮴을 축적하였다. 또한 2년차 연구에서 높은 농도의 희토류비료 시비는 보다 많은 량의 희토류 성분을 과실에 축적하여 과실내 희토류의 축적은 희토류비료의 시비량에 비례하였다. 이러한 희토류비료의 시비는 과실내의 다른 미량원소인 칼슘, 마그네슘과 칼륨의 농도에는 영향을 미치지 않았다. 희토류비료 시비에 따른 과실 품질조사에 있어, 희토류비료 0.2%의 엽면살포는 수확기 사과 과피의 붉은 색을 증가시켰으나, ‘후지’ 과실의 과중, 경도 및 산도는 변화가 없었다. 저장 사과의 희토류비료 시비효과를 조사한 결과, 희토류비료 처리된 사과의 경우 무처리에 비해 5개월 저장 후 과실의 연화 및 적정산도의 감소를 지연시키며, 호흡률과 에틸렌발생을 감소시켰다. Rare earth elements fertilizer and Ca were sprayed on eight-year-old ‘Fuji’/M.9 apple trees during two consecutive seasons, and fruit quality was quantified at harvest and 5-month long storing in a commercial cooling house at 4℃ and 80~85% RH. In the first season, single-sprayed of rare earth elements fertilizer showed appreciable accumulations of its elements (La, Pr, Gd, and Nd) in the fruit. In the following season, application of higher doses accumulated higher amount, indicating that the accumulation of rare earth elements was dose-dependent. However, rare earth elements did not affect the accumulations of Ca, Mg, and K in ‘Fuji’ apple fruit showed that there was no interaction between rare earth elements and these macronutrients. Double-spray of 0.2% rare earth elements increased fruit redness at harvest and had exhibited better color. Although at harvest it did not show significant effects on fruit weight, pulp firmness and titratable acidity (TA), but had pronounced effects on inhibiting fruit softness and retarded decrease of TA during storing. Furthermore, it reduced respiration rate and inhibited ethylene production during storing indicated that rare earth elements may be an alternative for prolonging the shelf life of ‘Fuji’/M.9 apple fruit.

Nonlinear Finite Element Modeling of Novel Partially Connected Buckling-Restrained Steel Plate Shear Walls

Mu-Wang Wei,J Y Richard Liew,Xue-Yi Fu 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.1

It has been demonstrated that the buckling-restrained steel plate shear wall (SPSW) is an effi cient and economic lateral loadresisting system exhibiting high performance on initial stiff ness, ductility, shear resistance, and energy dissipation capacity. In present study, a novel partially connected buckling-restrained SPSW is presented to reduce the stiff ness requirement for the vertical boundary elements. Meanwhile, nonlinear fi nite element (FE) analysis is performed to evaluate the behavior of the proposed shear wall system so that a large expense of conducting additional test can be saved. The experimental results from the literature and the test conducted by the authors are used to establish the validation of FE models. Based on the validated FE models, a further extensive parametric study is carried out to investigate the eff ect of initial imperfection, stiff ness of boundary elements, slenderness ratio (Height/Thickness) of the infi ll panel, aspect ratio (Height/Width) of the infi ll panel, RC cover panel thickness and bolt spacing on the behavior of the partially connected buckling-restrained SPSW.

An R package UnifiedDoseFinding for continuous and ordinal outcomes in Phase I dose-finding trials

Rongji Mu,Chia Wei Hsu,Shouhao Zhou,Haitao Pan 한국통계학회 2022 Communications for statistical applications and me Vol.29 No.4

Phase I dose-finding trials are essential in drug development. By finding the maximum tolerated dose (MTD) of a new drug or treatment, a Phase I trial establishes the recommended doses for later-phase testing. The primary toxicity endpoint of interest is often a binary variable, which describes an event of a patient who experiences dose-limiting toxicity. However, there is a growing interest in dose-finding studies regarding non-binary outcomes, defined by either the weighted sum of rates of various toxicity grades or a continuous outcome. Although several novel methods have been proposed in the literature, accessible software is still lacking to implement these methods. This study introduces a newly developed R package, UnifiedDoseFinding, which implements three phase I dose-finding methods with non-binary outcomes (Quasi- and Robust Quasi-CRM designs by Yuan it et al. (2007) and Pan it et al. (2014), gBOIN design by Mu it et al.(2019), and by a method by Ivanova and Kim (2009)). For each of the methods, UnifiedDoseFinding provides corresponding functions that begin with next_ that determines the dose for the next cohort of patients, select\_, which selects the MTD defined by the non-binary toxicity endpoint when the trial is completed, and get_oc, which obtains the operating characteristics. Three real examples are provided to help practitioners use these methods. The R package UnifiedDoseFinding, which is accessible in R CRAN, provides a user-friendly tool to facilitate the implementation of innovative dose-finding studies with nonbinary outcomes.

Genomic Correlates of Unfavorable Outcome in Locally Advanced Cervical Cancer Treated with Neoadjuvant Chemoradiation

Yuchun Wei,Chuqing Wei,Liang Chen,Ning Liu,Qiuxiang Ou,Jiani C. Yin,Jiaohui Pang,Zhenhao Fang,Xue Wu,Xiaonan Wang,Dianbin Mu,Yang Shao,Jinming Yu,Shuanghu Yuan 대한암학회 2022 Cancer Research and Treatment Vol.54 No.4

Purpose Neoadjuvant therapy modality can increase the operability rate and mitigate pathological risks in locally advanced cervical cancer, but treatment response varies widely. It remains unclear whether genetic alterations correlate with the response to neoadjuvant therapy and disease-free survival (DFS) in locally advanced cervical cancer. Materials and Methods A total of 62 locally advanced cervical cancer (stage IB-IIA) patients who received neoadjuvant chemoradiation plus radical hysterectomy were retrospectively analyzed. Patients’ tumor biopsy samples were comprehensively profiled using targeted next generation sequencing. Pathologic response to neoadjuvant treatment and DFS were evaluated against the association with genomic traits. Results Genetic alterations of PIK3CA were most frequent (37%), comparable to that of Caucasian populations from The Cancer Genome Atlas. The mutation frequency of genes including TERT, POLD1, NOS2, and FGFR3 was significantly higher in Chinese patients whereas RPTOR, EGFR, and TP53 were underrepresented in comparison to Caucasians. Germline mutations were identified in 21% (13/62) of the cohort and more than half (57%) had mutations in DNA damage repair genes, including BRCA1/2, TP53 and PALB2. Importantly, high tumor mutation burden, TP53 polymorphism (rs1042522), and KEAP1 mutations were found to be associated with poor pathologic response to neoadjuvant chemoradiation treatment. KEAP1 mutations, PIK3CA-SOX2 co-amplification, TERC copy number gain, and TYMS polymorphism correlated with an increased risk of disease relapse. Conclusion We report the genomic profile of locally advanced cervical cancer patients and the distinction between Asian and Caucasian cohorts. Our findings highlight genomic traits associated with unfavorable neoadjuvant chemoradiation response and a higher risk of early disease recurrence. PurposeNeoadjuvant therapy modality can increase the operability rate and mitigate pathological risks in locally advanced cervical cancer, but treatment response varies widely. It remains unclear whether genetic alterations correlate with the response to neoadjuvant therapy and disease-free survival (DFS) in locally advanced cervical cancer.Materials and MethodsA total of 62 locally advanced cervical cancer (stage IB-IIA) patients who received neoadjuvant chemoradiation plus radical hysterectomy were retrospectively analyzed. Patients’ tumor biopsy samples were comprehensively profiled using targeted next generation sequencing. Pathologic response to neoadjuvant treatment and DFS were evaluated against the association with genomic traits.ResultsGenetic alterations of <i>PIK3CA</i> were most frequent (37%), comparable to that of Caucasian populations from The Cancer Genome Atlas. The mutation frequency of genes including <i>TERT, POLD1, NOS2</i>, and <i>FGFR3</i> was significantly higher in Chinese patients whereas <i>RPTOR, EGFR</i>, and <i>TP53</i> were underrepresented in comparison to Caucasians. Germline mutations were identified in 21% (13/62) of the cohort and more than half (57%) had mutations in DNA damage repair genes, including <i>BRCA1/2, TP53</i> and <i>PALB2</i>. Importantly, high tumor mutation burden, <i>TP53</i> polymorphism (rs1042522), and <i>KEAP1</i> mutations were found to be associated with poor pathologic response to neoadjuvant chemoradiation treatment. <i>KEAP1</i> mutations, <i>PIK3CA-SOX2</i> co-amplification, <i>TERC</i> copy number gain, and <i>TYMS</i> polymorphism correlated with an increased risk of disease relapse.ConclusionWe report the genomic profile of locally advanced cervical cancer patients and the distinction between Asian and Caucasian cohorts. Our findings highlight genomic traits associated with unfavorable neoadjuvant chemoradiation response and a higher risk of early disease recurrence.

Applying Multifractal Spectrum Theory to Fingerprint Features Recognition

Hai Ming Ni,Da Wei Qi,Hongbo Mu 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.1

Fingerprint features recognition which can be used to distinguish between individuals is an intriguing study with many potential applications. In this paper, a new method for fingerprint recognition based on multifractal spectrum theory was proposed. The recognition process can be divided into the following main steps: (1) Extracting the core point in fingerprint; (2) Fragmenting the fingerprint image to get a subimage with fixed size; (3) Thinning the fingerprint image by using an improved OPTA algorithm; (4) Segmenting the curves in fingerprint image into digital straight segments with normalized straight length threshold; (5) Selecting the appropriate dividing scale to segment the processed fingerprint image; (6) Calculating and analyzing the multifractal spectrum curve - f (a) ; (7) Fitting curve equation and extracting the characteristic parameters of a - f(a); (8) Finally, the parameters matching and fingerprint feature recognition. A large number of experimental results show that our method is effective.

Delay of Surgery for Spinal Metastasis due to the COVID-19 Outbreak Affected Patient Outcomes

Chia-Jung Hsieh,Chun-Yu Wu,Yen-Heng Lin,Yu-Cheng Huang,Wen-Chi Yang,Tom Wei-Wu Chen,Wei-Li Ma,Wei-Hsin Lin,Feng-Ming Hsu,Furen Xiao,Shih-Hung Yang,Dar-Ming Lai,Chang-Mu Chen,Shin-Yi Chao,Fon-Yih Tsuan 대한척추신경외과학회 2023 Neurospine Vol.20 No.4

Objective: The present study is to analyze the effects of the coronavirus disease 2019 (COVID 2019) outbreak and the subsequent lockdown on the outcomes of spinal metastasis patients. Methods: The study was a retrospective analysis of data from a prospective cohort study. All patients underwent surgical intervention for spinal metastases between January 2019 and December 2021 and had at least 3 months of postoperative follow-up. The primary outcome was overall mortality during the 4 different stages (pre-COVID-19 era, COVID-19 pandemic except in Taiwan, national lockdown, lifting of the lockdown). The secondary outcomes were the oncological severity scores, medical/surgical accessibility, and patient functional outcome during the 4 periods as well as survival/mortality. Results: A total of 233 patients were included. The overall mortality rate was 41.20%. During the Taiwan lockdown, more patients received palliative surgery than other surgical methods, and no total en bloc spondylectomy was performed. The time from surgeon visit to operation was approximately doubled after the COVID-19 outbreak in Taiwan (75.97, 86.63, 168.79, and 166.91 hours in the 4 periods, respectively). The estimated survival probability was highest after the national lockdown was lifted and lowest during the lockdown. In the multivariate analysis, increased risk of mortality was observed with delay of surgery, with emergency surgery having a higher risk with delays above 33 hours, urgent surgery (below 59 and above 111 hours), and elective surgery (above 332 hours). Conclusion: The COVID-19 pandemic and related policies have altered daily clinical practice and negatively impacted the survival of patients with spinal metastases.

Iterative tuning of decoupling controller for 3-DOF precision motion stage

Wei Teng,Qingfeng Gao,Xin Wu,Haihua Mu 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.2

A practical iterative tuning algorithm of a decoupling controller is presented to eliminate intrinsic coupling among 3-DOF precision motion stage. General decoupling control cannot eliminate coupling completely, which will prevent the enhancement of control accuracy in high-precision motion system. The proposed algorithm can be used to tune the parameters of a decoupling controller iteratively through minimizing a quadratic cost function of the tracking error in non-movement direction when the stage moves in one direction. The tuning algorithm addressed for the motion stage needs only measurement signals in an actual motion system rather than a detailed model of the stage. The proposed algorithm is demonstrated by experimental results. It can be applied further in other multi-DOF motion systems.

Pristimerin Inhibits Breast Cancer Cell Migration by Up-regulating Regulator of G Protein Signaling 4 Expression

Mu, Xian-Min,Shi, Wei,Sun, Li-Xin,Li, Han,Wang, Yu-Rong,Jiang, Zhen-Zhou,Zhang, Lu-Yong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Background/Aim: Pristimerin isolated from Celastrus and Maytenus spp can inhibit proteasome activity. However, whether pristimerin can modulate cancer metastasis is unknown. Methods: The impacts of pristimerin on the purified and intracellular chymotrypsin proteasomal activity, the levels of regulator of G protein signaling 4 (RGS 4) expression and breast cancer cell lamellipodia formation, and the migration and invasion were determined by enzymatic, Western blot, immunofluorescent, and transwell assays, respectively. Results: We found that pristimerin inhibited human chymotrypsin proteasomal activity in MDA-MB-231 cells in a dose-dependent manner. Pristimerin also inhibited breast cancer cell lamellipodia formation, migration, and invasion in vitro by up-regulating RGS4 expression. Thus, knockdown of RGS4 attenuated pristimerin-mediated inhibition of breast cancer cell migration and invasion. Furthermore, pristimerin inhibited growth and invasion of implanted breast tumors in mice. Conclusion: Pristmerin inhibits proteasomal activity and increases the levels of RGS4, inhibiting the migration and invasion of breast cancer cells.