Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 6 de 6
Filter
Add more filters










Language
Publication year range
1.
Membranes (Basel) ; 12(2)2022 Jan 30.
Article in English | MEDLINE | ID: mdl-35207089

ABSTRACT

In this study, ZnO, AlZnO, Al2O3, and Al2O3-doped ZnO-sensing membranes were fabricated in electrolyte-insulator-semiconductor (EIS) structures. Multiple material analyses indicate that annealing at an appropriate temperature of 500 °C could enhance crystallizations, passivate defects, and facilitate grainizations. Owing to their material properties, both the pH-sensing capability and overall reliability were optimized for these four types of membranes. The results also revealed that higher Al amounts increased the surface roughness values and enhanced larger crystals and grains. Higher Al compositions resulted in higher sensitivity, linearity, and stability in the membrane.

2.
Membranes (Basel) ; 11(12)2021 Dec 20.
Article in English | MEDLINE | ID: mdl-34940496

ABSTRACT

In this study, the effects of magnesium (Mg) doping and Ammonia (NH3) plasma on the pH sensing capabilities of InGaZnO membranes were investigated. Undoped InGaZnO and Mg-doped pH sensing membranes with NH3 plasma were examined with multiple material analyses including X-ray diffraction, X-ray photoelectron spectroscopy, secondary ion mass spectroscopy and transmission electron microscope, and pH sensing behaviors of the membrane in electrolyte-insulator-semiconductors. Results indicate that Mg doping and NH3 plasma treatment could superpositionally enhance crystallization in fine nanostructures, and strengthen chemical bindings. Results indicate these material improvements increased pH sensing capability significantly. Plasma-treated Mg-doped InGaZnO pH sensing membranes show promise for future pH sensing biosensors.

3.
Membranes (Basel) ; 11(11)2021 Nov 22.
Article in English | MEDLINE | ID: mdl-34832131

ABSTRACT

ZnO/ZnS nanocomposite-based nanostructures exhibit dual light and gas sensing capabilities. To further boost the light/dual sensing properties, gold nanoparticles (Au NPs) were incorporated into the core-shell structures. Multiple material characterizations revealed that Au NPs were successfully well spread and decorated on ZnO/ZnS nanostructures. Furthermore, our findings show that the addition of Au NPs could enhance both 365 nm UV light sensing and hydrogen gas sensing in terms of light/gas sensitivity and light/gas response time. We postulate that the optimization of gas/light dual sensing capability may result from the induced electric field and inhabitation of electron-hole recombination. Owing to their compact size, simple fabrication, and stable response, ZnO/ZnS/Au NPs-based light/gas dual sensors are promising for future extreme environmental monitoring.

4.
NMR Biomed ; 26(12): 1705-13, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23940080

ABSTRACT

The aim of this study was to evaluate the change of breast density in the normal breast of patients receiving neoadjuvant chemotherapy (NAC). Forty-four breast cancer patients were studied. MRI acquisition was performed before treatment (baseline), and 4 and 12 weeks after treatment. A computer-algorithm-based program was used to segment breast tissue and calculate breast volume (BV), fibroglandular tissue volume (FV), and percent density (PD) (the ratio of FV over BV × 100%). The reduction of FV and PD after treatment was compared with baseline using paired t-tests with a Bonferroni-Holm correction. The association of density reduction with age was analyzed. FV and PD after NAC showed significant decreases compared with the baseline. FV was 110.0 ml (67.2, 189.8) (geometric mean (interquartile range)) at baseline, 104.3 ml (66.6, 164.4) after 4 weeks (p < 0.0001), and 94.7 ml (60.2, 144.4) after 12 weeks (comparison with baseline, p < 0.0001; comparison with 4 weeks, p = 0.016). PD was 11.2% (6.4, 22.4) at baseline, 10.6% (6.6, 20.3) after 4 weeks (p < 0.0001), and 9.7% (6.2, 17.9) after 12 weeks (comparison with baseline, p = 0.0001; comparison with 4 weeks, p = 0.018). Younger patients tended to show a higher density reduction, but overall correlation with age was only moderate (r = 0.28 for FV, p = 0.07, and r = 0.52 for PD, p = 0.0003). Our study showed that breast density measured from MR images acquired at 3T MR can be accurately quantified using a robust computer-aided algorithm based on non-parametric non-uniformity normalization (N3) and an adaptive fuzzy C-means algorithm. Similar to doxorubicin and cyclophosphamide regimens, the taxane-based NAC regimen also caused density atrophy in the normal breast and showed reduction in FV and PD. The effect of breast density reduction was age related and duration related.


Subject(s)
Breast Neoplasms/drug therapy , Breast/pathology , Bridged-Ring Compounds/therapeutic use , Magnetic Resonance Imaging , Neoadjuvant Therapy , Taxoids/therapeutic use , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/metabolism , Breast/drug effects , Bridged-Ring Compounds/pharmacology , Female , Humans , Middle Aged , Organ Size/drug effects , Taxoids/pharmacology
5.
Med Phys ; 39(8): 4886-95, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22894415

ABSTRACT

PURPOSE: To compare the breast volume (BV), fibroglandular tissue volume (FV), and percent density (PD) measured from breast MRI of the same women using four different MR scanners. METHODS: The study was performed in 34 healthy Asian volunteers using two 1.5T (GE and Siemens) and two 3T (GE and Philips) MR scanners. The BV, FV, and PD were measured on nonfat-suppressed T1-weighted images using a comprehensive computer algorithm-based segmentation method. The scanner-to-scanner measurement difference, and the coefficient of variation (CV) among the four scanners were calculated. The measurement variation between two density morphological patterns presenting as the central type and the intermingled type was separately analyzed and compared. RESULTS: All four scanners provided satisfactory image quality allowing for successful completion of the segmentation processes. The measured parameters between each pair of MR scanners were highly correlated, with R(2) ≥ 0.95 for BV, R(2) ≥ 0.99 for FV, and R(2) ≥ 0.97 for PD in all comparisons. The mean percent differences between each pair of scanners were 5.9%-7.8% for BV, 5.3%-6.5% for FV, 4.3%-7.3% for PD; with the overall CV of 5.8% for BV, 4.8% for FV, and 4.9% for PD. The variation of FV was smaller in the central type than in the intermingled type (p = 0.04). CONCLUSIONS: The results showed that the variation of FV and PD measured from four different MR scanners is around 5%, suggesting the parameters measured using different scanners can be used for a combined analysis in a multicenter study.


Subject(s)
Breast/pathology , Magnetic Resonance Imaging/methods , Adipose Tissue/pathology , Adult , Algorithms , Asian People , Equipment Design , Female , Humans , Image Processing, Computer-Assisted/methods , Middle Aged , Models, Statistical , Reproducibility of Results
6.
Article in English | WPRIM (Western Pacific) | ID: wpr-234095

ABSTRACT

<p><b>INTRODUCTION</b>Cardiopulmonary resuscitation (CPR) guidelines were revised in 2005 based on new evidence and expert consensus. However, the benefits of the new guidelines remain undetermined and their influence has not been published in Asia. This study aimed to evaluate the impact of implementing the new resuscitation guidelines and identify factors that influence the discharge survival of out-of-hospital cardiac arrest (OHCA) patients in an Asian metropolitan city.</p><p><b>MATERIALS AND METHODS</b>This was an observational cohort study of all OHCA patients seen by the emergency medical service during the period before (Nov 2003 to Oct 2005) and after (May 2006 to Oct 2008) implementing the new resuscitation guidelines. Detailed clinical information was recorded using the Ustein style template. Statistical analysis was done using X2 test or t-test for univariate analysis and the logistic regression model for multivariate analysis.</p><p><b>RESULTS</b>There were 463 patients before and 430 patients after the new guidelines who received resuscitation. The rate of recovery of spontaneous circulation (ROSC), survival-to-intensive care unit (ICU) admission, and survival-to-hospital discharge all showed no benefits regarding the new resuscitation guidelines (ROSC: 42% vs 39%, P = 0.32; Survival-to-ICU admission: 33% vs 30%, P = 0.27; survival-to-hospital discharge: 10% vs 7%, P = 0.09). The rate of ventricular fibrillation/pulseless ventricular tachycardia (VF/pulseless VT), rate of witnessed arrest, and rate of bystander CPR were much lower than in Western studies. After multivariate logistic regression, factors related to discharge survival were witnessed arrest and initial rhythm with VF/pulseless VT. The new resuscitation guidelines did not significantly influence the discharge survival.</p><p><b>CONCLUSIONS</b>We did not observe any improvement in survival after implementing the new guidelines. Independent factors of survival-to-hospital discharge are witnessed arrest and initial rhythm with VF/pulseless VT. Because the rates of VF/pulseless VT and bystander CPR in Asia are low, popularising CPR training programmes and increasing the rate of bystander CPR may be more important for improving OHCA survival rates than frequent guideline changes.</p>


Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Cardiopulmonary Resuscitation , Methods , Reference Standards , Emergency Service, Hospital , Hospitals, University , Out-of-Hospital Cardiac Arrest , Mortality , Therapeutics , Patient Discharge , Practice Guidelines as Topic , Survival Analysis , Taiwan , Epidemiology
SELECTION OF CITATIONS
SEARCH DETAIL
...