Yen-Ju Chen

Dr. Yen-Ju Chen

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 October 2013 in IEEE Transactions on Microwave Theory and Techniques
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Journal Article
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YCYen-Ju Chen
Yen-Ju Chen
TCTa-Shun Chu
Ta-Shun Chu
A direct-coupled technique for standing wave oscillator (SWO) arrays is presented in this paper. The oscillation currents of a unit cell in the SWO array directly inject to adjacent cells through the resonator. Two 2-D SWO arrays based on the technique are reported. The first SWO array can provide synchronous signals with identical frequencies, amplitudes, and phases at multiple locations over a chip. It is implemented in a 90-nm CMOS technology with 61.5-GHz oscillation frequency. Millimeter-wave radiators that consists of the proposed SWO array, an RF driver array, and an on-chip loop antenna array are implemented in a single chip to verify the synchronicity of the reported 2-D SWO via wireless measurement. The indirect evidence of synchronicity is provided from the correlation between the wireless measured effective isotropic radiated power (EIRP) and phase noise of 1 × 1, 2 × 2, and 3 × 3 arrays. The EIRP in the normal direction of the array is increasing by a factor of 10 log N2 and the phase noise is reducing by a factor of 10 log N over that of a single cell, where N is the number of unit cells in the array. The second SWO array can provide synchronous signals with identical frequencies, amplitudes, and multiple phases at multiple locations over a chip. It is implemented in a 65-nm CMOS technology with 132.5-GHz fundamental frequency. The SWO array is designed for a 2-D second-harmonic (265 GHz) spatial power radiating and combining array. The EIRPs of the fundamental frequency and second harmonic in the normal direction of the array are -34 and -6.5 dBm, respectively. The phase noise of the fundamental frequency and second harmonic at 1-MHz offset from the carrier frequency are -96 and -89 dBc/Hz, respectively.

16 July 2023 in Viruses
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Journal Article
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YCYen-Ju Chen
Yen-Ju Chen
JHJason Huang
Jason Huang
CYChing-Ping Yang
Ching-Ping Yang
KHKuo-Feng Hsu
Kuo-Feng Hsu
HLHsin-Fu Liu
Hsin-Fu Liu
We developed a convenient method for amplifying the complete SARS-CoV-2 sequence using in-house RT-PCR without virus culture. Forty-one stored throat swabs and blood specimens were collected from eight SARS-CoV-2 infections at multiple time points. Total RNA was extracted using the QIAamp viral RNA mini kit and pooled for higher RNA levels. Only those positive specimens by commercial real-time RT-PCR (RT-qPCR) were selected and amplified by in-house RT-PCR for complete sequences, followed by sequencing. Phylogenetic trees and exploratory analyses were performed using MEGA 11 and Simplot 3.5.1 software. Swab samples had significantly higher total RNA concentrations than plasma (p < 0.01). Positive results were found mainly in swabs, but one was found in plasma. Successful gene amplification depended on Ct values (Ct < 38). A non-synonymous substitution was found in ORF1ab/Nsp3 (at NC045512.2 position 6312, C to A) and most spike protein mutations occurred in the S1 subunit (residues 14–685). The proposed method is time-saving and reliable for rapid genomic analysis. Increasing sample volume and pooling them for RNA extraction increases RNA concentration without culture. Combining nucleotide sequences from specific variable regions of the genome is more efficient than conventional methods.

1 October 2022 in Molecular Biotechnology
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GLGang-Hua Lin
Gang-Hua Lin
SWShu-Hsien Wu
Shu-Hsien Wu
YKYu-Chun Ko
Yu-Chun Ko
CLChien-Hua Lin
Chien-Hua Lin
GLGuo-Shiou Liao
Guo-Shiou Liao
KHKuo-Feng Hsu
Kuo-Feng Hsu

18 January 2024 in Viruses
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YCYen-Ju Chen
Yen-Ju Chen
YLYu-Chen Lin
Yu-Chen Lin
MWMeng-Tien Wu
Meng-Tien Wu
JKJenn-Yuan Kuo
Jenn-Yuan Kuo
CWChun-Hsiang Wang
Chun-Hsiang Wang
This study aimed to explore the current evidence on preventing blood-borne virus infections among people who inject drugs (PWID). We conducted a comprehensive search across three databases (PubMed, Embase, Cochrane Library) for relevant articles published in English between 2014 and 2023. We followed the Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA) guidelines, assessed the quality of the paper using the revised Cochrane Risk of Bias Tool (ROB 2), and conducted a meta-analysis using RevMan 5.3. Completing the harm reduction program (HRP) participation and receiving all three vaccine doses resulted in a 28% reduction in the risk of HBV infection (OR: 0.72, 95% CI: 0.37–1.42). Various interventions increased the willingness of PWIDs to undergo HCV treatment (OR: 5.91, 95% CI: 2.46–14.24) and promoted treatment adherence (OR: 15.04, 95% CI: 2.80–80.61). Taking PrEP, participating in HRP, and modifying risky behaviors were associated with a 33% reduction in the risk of HIV infection (OR: 0.67, 95% CI: 0.61–0.74). Conducting referrals, providing counseling, and implementing antiretroviral therapy resulted in a 44% reduction in the risk of viral transmission (OR: 0.56, 95% CI: 0.47–0.66). Co-infection may potentially compromise effectiveness, so it is important to consider drug resistance.

28 September 2022 in Viruses
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YCYen-Ju Chen
Yen-Ju Chen
JHJason Huang
Jason Huang
HHung-Chin Tsai
Hung-Chin Tsai
YLYu-Hui Lin
Yu-Hui Lin
KHKuo-Feng Hsu
Kuo-Feng Hsu
HLHsin-Fu Liu
Hsin-Fu Liu
Persons who inject drugs (PWID) and their risk-related behaviors (e.g., unprotected sex and sharing needles/syringes/other injection equipment) have caused severe public health problems, especially in the rapid spread of HIV-1 and HCV. Here, we reconstructed the epidemic history of HIV-1 circulating recombinant form (CRF) 01_AE, CRF07_BC, and HCV subtype-6w among Taiwanese PWID. The timescales were estimated using phylogenetic and Bayesian coalescent analyses. The results revealed that CRF01_AE started to circulate in the Taiwanese PWID population in central Taiwan at 1992.5 (95% credible region: 1988.8–1995.9) and spread to other regions of Taiwan, while CRF07_BC was first identified in southern Taiwan at 2000.0 (95% CR: 1997.8–2002.2) and then spread northward to central-northern Taiwan. All HCV-6 strains were from Asia (that is, China, Myanmar, Taiwan, and Vietnam) and originated in 1928.1 (95% CR: 1890.2–1966.0). Furthermore, subtype-6w isolates from different regions of Taiwan appeared to share a common source that existed in the mid-1990s (95% CR: 1985.0–2001.8) or thereabouts. The routes of drug trafficking and the resulting high prevalence of HIV-1/HCV co-infections among PWID might have contributed to the virus transmission and promoted its spread worldwide. Long-term monitoring and policy implementation in at-risk populations would be useful for disease control.

27 November 2024 in Journal of Clinical Medicine
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HCHsun-Hao Chang
Hsun-Hao Chang
CHChi-Feng Hung
Chi-Feng Hung
YCYen-Ju Chen
Yen-Ju Chen
CFChing-Chang Fang
Ching-Chang Fang
Background/Objectives: The efficacy and safety of reduced-dose prasugrel (loading dose/maintenance dose: 20/3.75 mg) in preventing major adverse cardiovascular events (MACEs) among patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) have been well-estab-lished. However, long-term real-world data for this population remains limited in Taiwan. Methods: This study enrolled 226 Taiwanese ACS patients (with 448 lesions) who received reduced-dose pra-sugrel after PCI and completed one year of follow-up. Results: The primary efficacy outcome was the in-cidence of MACEs. After one year, the MACE rate was 7.1% (16/226). A comparative analysis of MACEs was conducted across subgroups stratified by age (<75 vs. ≥75 years), body mass index (<25 vs. ≥25 kg/m2), body weight (<60 vs. ≥60 kg), and estimated glomerular filtration rate (<60 vs. ≥60 mL/min/1.73 m2). Patients with impaired renal function had a 4.03-fold higher risk (95% con-fidence interval = 1.37–11.90, p = 0.01) of MACEs than those with optimal renal function. The primary safety endpoint was major bleeding events (Bleeding Academic Research Consortium types 3 or 5), which occurred in 0.8% (2/226) of patients, all gastrointestinal. The secondary end-point was net adverse clinical events (NACEs), a composite of MACEs and major bleeding, with an observed rate of 8.0% (18/226). Conclusions: Reduced-dose prasugrel demonstrated both safety and efficacy in Taiwanese ACS patients undergoing PCI.