Publications by authors named "Yu-Jen Cheng"

Monitoring deep tissue biometrics is crucial in various clinical settings, including internal hemorrhage. Although optical and impedance tomography techniques offer real-time monitoring with minimal medical infrastructure, they still face challenges in accurately assessing deeper tissues in wearable formats. This study introduces a novel single-electrode capacitive sensor designed to measure deep tissue capacitance changes caused by variations in dielectric constant and pressure.

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In this article, we consider the semiparametric transformation models with a shared frailty variable for the rate function of recurrent events, where a shared frailty model is imposed to enable a correlation between the recurrent event process and the censoring time. Unlike the commonly used shared-frailty proportional rate models, our models allow for the rate functions associated with any two sets of covariate values not to be proportional over time. The proposed estimating approaches are inspired by Wang and Huang, who decompose the rate function into shape and size components.

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In this study, we investigate estimation and variable selection for semiparametric transformation models with length-biased survival data-a special case of left truncation commonly encountered in the social sciences and cancer prevention trials. To correct for sampling bias, conventional methods such as conditional likelihood, martingale estimating equations, and composite likelihood have been proposed. However, these methods may be less efficient due to their reliance on only partial information from the full likelihood.

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A multimodal sensor array, combining pressure and proximity sensing, has attracted considerable interest due to its importance in ubiquitous monitoring of cardiopulmonary health- and sleep-related biometrics. However, the sensitivity and dynamic range of prevalent sensors are often insufficient to detect subtle body signals. This study introduces a novel capacitive nanocomposite proximity-pressure sensor (NPPS) for detecting multiple human biometrics.

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Leveraging information in aggregate data from external sources to improve estimation efficiency and prediction accuracy with smaller scale studies has drawn a great deal of attention in recent years. Yet, conventional methods often either ignore uncertainty in the external information or fail to account for the heterogeneity between internal and external studies. This article proposes an empirical likelihood-based framework to improve the estimation of the semiparametric transformation models by incorporating information about the t-year subgroup survival probability from external sources.

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Methylated cell-free DNA (cfDNA) has been deemed a promising biomarker for ovarian cancer (OvCa) prognosis and therapy selection. However, exploring the methylation profiles of tumor suppressor genes in cfDNA remains a challenge due to their extremely low concentrations and complicated protocols, as well as methodological constraints. In this study, an integrated microfluidic system was developed to automatically (1) capture methylated cfDNA in plasma by magnetic beads coated with the methyl-CpG-binding domain and (2) quantify the methylation level of tumor suppressor genes by on-chip quantitative polymerase chain reaction (qPCR).

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In biomedical studies involving survival data, the observation of failure times is sometimes accompanied by a variable which describes the type of failure event (Kalbeisch and Prentice, 2002). This paper considers two specific challenges which are encountered in the joint analysis of failure time and failure type. First, because the observation of failure times is subject to left truncation, the sampling bias extends to the failure type which is associated with the failure time.

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In multivariate recurrent event data regression, observation of recurrent events is usually terminated by other events that are associated with the recurrent event processes, resulting in informative censoring. Additionally, some covariates could be measured with errors. In some applications, an instrumental variable is observed in a subsample, namely a calibration sample, which can be applied for bias correction.

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This study aims to identify new upregulated genes related to secretory or membranous proteins to help detect esophageal squamous cell carcinoma (ESCC). First, we performed microarray-based screening of esophageal tumors from both N-nitrosomethylbenzylamine- and arecoline-induced F344 rats and seventeen human ESCC specimens. Candidate genes were validated by quantitative PCR (qPCR) and immunohistochemical (IHC) staining of ESCC tissues.

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Recurrent event data arise frequently in many longitudinal follow-up studies. Hence, evaluating covariate effects on the rates of occurrence of such events is commonly of interest. Examples include repeated hospitalizations, recurrent infections of HIV, and tumor recurrences.

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Adipose tissue is now considered as an endocrine organ involved in metabolic and inflammatory reactions. Adiponectin, a 244-amino acid peptide hormone, is associated with insulin resistance and carcinogenesis. Curcumin (diferuloylmethane) is the principal curcuminoid of the popular Indian spice, turmeric.

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Objective: The purpose of this study was to determine the efficacy of the Lidopat(®) 5% skin patch in relieving rib fracture pain.

Subjects And Methods: From June 2009 to May 2011, 44 trauma patients with isolated rib fractures were enrolled in this study and randomized in a double-blind method into 2 groups. The experimental group (group E: 27 patients) used a Lidopat(®) 5% skin patch at the trauma site and took an oral analgesic drug for pain relief.

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This article presents methods and inference for causal estimation in semiparametric transformation models for the prevalent survival data. Through the estimation of the transformation models and covariate distribution, we propose a few analytical procedures to estimate the causal survival function. As the data are observational, the unobserved potential outcome (survival time) may be associated with the treatment assignment, and therefore there may exist a systematic imbalance between the data observed from each treatment arm.

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Background/objective: Cosmetic factors are important when considering minimally invasive surgery. For cosmetic improvement, a complete thoracoscopic lobectomy is accomplished via the three-port two-instrument (TPTI) technique. The resected specimen is removed without extending the port wounds.

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Adjuvant chemotherapy is commonly given to surgically treated non-small-cell lung cancer (NSCLC) patients. However, the prerequisite for chemotherapy needs to be scrutinized in order to maximize the benefits to patients. In this study, we observed that NSCLC cells with high Id1 protein expression were vulnerable to the treatment of paclitaxel and cisplatin.

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This study was intended to investigate the trend in vancomycin susceptibility and correlation with molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) causing invasive infections. A total of 670 MRSA isolates were collected from patients with invasive infections as part of bacterial collection in the Tigecycline in vitro Surveillance in Taiwan (TIST) from 2006 to 2010. MICs of the isolates to vancomycin were determined using the agar dilution method.

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Survival data are subject to length-biased sampling when the survival times are left-truncated and the underlying truncation time random variable is uniformly distributed. Substantial efficiency gains can be achieved by incorporating the information about the truncation time distribution in the estimation procedure [Wang (1989) Journal of the American Statistical Association 84, 742-748; Wang (1996) Biometrika 83, 343-354]. Under the semiparametric transformation models, the maximum likelihood method is expected to be fully efficient, yet it is difficult to implement because the full likelihood depends on the nonparametric component in a complicated way.

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Heat-shock proteins (HSPs) are molecular chaperones that protect proteins from damage. HSP27 expression is associated with cancer transformation and invasion. Ginkgo biloba extract (EGb761), the most widely sold herbal supplement, has antiangiogenic effects and induces tumor apoptosis.

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Background: Focal hypermethylation in promoter regions of tumor suppressor genes against the background of global hypomethylation is a landmark of carcinogenesis. This study aimed to investigate the methylation status of retinoic acid receptor beta2 (RARβ2) and long interspersed nuclear elements (LINE-1) in different stages of esophageal squamous cell carcinoma (ESCC).

Method: The tumor and adjacent normal esophageal tissues from 125 male ESCC patients who underwent primary surgery were analyzed for the methylation status of RARβ2 promoter and LINE-1 through methylation-specific polymerase chain reaction and pyrosequencing.

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Background: Whether antituberculosis (anti-TB) treatment in patients with chronic viral hepatitis affects the incidence and onset time of drug-induced hepatotoxicity (DIH) is still controversial. The aim of this retrospective study was to find out whether chronic viral hepatitis affects the incidence and onset time of DIH.

Methods: All patients diagnosed with active TB and being treated at a tertiary referral hospital between 2002 and 2009 were identified from medical records, from which 553 patients were enrolled in the study.

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Objective: Development of flavonoids as potential chemotherapeutic agents for cervical cancer may open new avenues in anticancer drug design. In this study, the cytotoxic activity and anti-migration/invasion/angiogenesis efficiency of the synthetic flavonoid WYC02-9 on cervical cancer and the underlying mechanisms are explored.

Methods: XTT cell viability assay, apoptosis assays, cell cycle analysis, and immunoblotting analysis were applied to study the biologic activity of WYC02-9.

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Human psittacosis caused by Chlamydophila psittaci is one of the most common zoonotic atypical pneumonias featuring pulmonary as well as extrapulmonary infections. Most of the cases involve avian contact history especially with psittacine birds. Herein we report a 44-year-old male patient displaying atypical pneumonia symptoms of intermittent fever, dry cough, chest pain, dyspnea, headache, hepatitis, and hyponatremia.

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Isolates of Streptococcus pneumoniae (n = 530) were collected from 20 hospitals in different parts of Taiwan from 2006 to 2010. MICs to 16 antimicrobial agents were determined by broth dilution method and serotypes were identified by latex agglutination. Based on meningitis (non-meningitis) criteria established by the CLSI, 11.

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