Browsing by Author "Wu, Min-Hsien"

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Development of High-kappa Eu2Ti2O7 EIS Devices Using Poly-N-isopropylacrylamide as an Enzyme Encapsulation Material for pH Detection and Uric Acid Biosensing
(2012-01-01)
Pan, Tung-Ming
;
Chang, Kung-Yuan
;
Wu, Min-Hsien
;
Tsai, Shiao-Wen
;
Ko, Fu-Hsiang
In this study, we proposed an electrolyte-insulator-semiconductor (EIS) device fabricating a high-kappa Eu2Ti2O7 sensing membrane deposited on Si substrates through cosputtering for pH detection and uric acid biosensing applications. The EIS device incorporating a high-kappa Eu2Ti2O7 sensing membrane annealed at 900 degrees C exhibited a higher sensitivity of 59.03 mV/pH, a smaller hysteresis voltage of 2.8 mV, and a lower drift rate of 0.586 mV/h compared to those of the other annealing temperatures. These results are attributed to the small number of crystal defects and the large surface roughness. Furthermore, for high-kappa Eu2Ti2O7 EIS-based biosensing application, a phase tunable poly-N-isopropylacrylamide (PNIPAAm) was used as an enzyme encapsulating material, making the loading and removal of a biological recognition element on a biosensor easily. In this study, a hybrid configuration of the high-kappa Eu2Ti2O7 EIS biosensor with an unease-immobilizing PNIPAAm film attached was established and was demonstrated for uric acid biosensing. The sensitivity of a Eu2Ti2O7 EIS biosensor was 17.6 mV/mM for uric acid concentrations ranging from 2 to 8 mM.
The Prognostic Value of Circulating Tumor Cells in Asian Neuroendocrine Tumors
(2019-12-27)
Hsieh, Jason Chia-Hsun
;
Chen, Guan-Yu
;
Jhou, David Da-Wei
;
Chou, Wen-Chi
;
Yeh, Chun-Nan
Circulating tumor cells (CTC) play important roles in various cancers; however, few studies have assessed their clinical utility in neuroendocrine tumors. This study aimed to prospectively evaluate the prognostic value of CTC counts in Asian patients with neuroendocrine tumors before and during anti-cancer therapy. Patients who were diagnosed with unresectable histological neuroendocrine tumors between September 2011 and September 2017 were enrolled. CTC testing was performed before and during anti-cancer therapy using a negative selection protocol. Chromogranin A levels were also assessed. Univariate and multivariate Cox's proportional hazard model with forward LR model was performed to investigate the impact of independent factors on overall survival and progression-free survival. Kaplan-Meier method with log-rank tests were used to determine the difference among different clinicopathological signatures and CTC cutoff. The baseline CTC detection rate was 94.3% (33/35). CTC counts were associated with cancer stages (I-III vs. IV, P = 0.015), liver metastasis (P = 0.026), and neuroendocrine tumor grading (P = 0.03). The median progression-free survival and overall survivals were 12.3 and 30.4 months, respectively. In multivariate Cox regression model, neuroendocrine tumors grading and baseline CTC counts were both independent prognostic factors for progression-free survival (PFS, P = 0.005 and 0.015, respectively) and overall survival (OS, P = 0.018 and 0.023, respectively). In Kaplan-Meier analysis, lower baseline chromogranin A levels were associated with longer PFS (P = 0.024). Baseline CTC counts are associated with the clinicopathologic features of neuroendocrine tumors and are an independent prognostic factor for this malignancy.