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ABSTRACT: To identify optical coherence tomography (OCT) patterns in diabetic macular edema (DME) that were predictive of visual outcomes after intravitreal bevacizumab (IVB) injection.
This was a retrospective study. We examined 31 eyes (24 patients) with clinically significant macular edema that received IVB injections along with macular OCT data. The eyes were categorized into 4 groups by using OCT features: diffuse retinal thickening (DRT), cystoid macular edema (CME), serous retinal detachment (SRD), and vitreomacular interface abnormalities (VMIAs). Changes in retinal thickness, retinal volume, and visual acuity (VA) after IVB injection were compared on the basis of OCT patterns.
After IVB injections, changes in VA logarithm of the minimum angle of resolution were -0.06±0.36, -0.26±0.26, 0.09±0.13, and -0.08±0.15, respectively, for DRT, CME, SRD, and VMIA patterns. Central macular thickness decreased by 70.5±105.5, 110.67±97.28, 181±125.87, and 24.25±77.12 μm for the DRT, CME, SRD, and VMIA patterns, respectively. The CME group was associated with a greater reduction in retinal thickness (P=0.009) and volume (P=0.027) with superior VA improvement (P=0.012) as compared with the DRT, SRD, and VMIA groups.
Patients with CME gained greater improvement in visual acuity and macular thickness and volume after IVB injection had been administered as the primary treatment for DME, as compared with other patients. The OCT patterns of DME may indicate the appropriate treatment; we consider these patterns to be prognostic of the response to IVB injection for macular edema.
Journal of ocular pharmacology and therapeutics: the official journal of the Association for Ocular Pharmacology and Therapeutics 02/2012; 28(1):59-64. · 1.46 Impact Factor
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ABSTRACT: The feasibility of stabilizing copper-laden sludge by high-temperature CuFe(2)O(4) ferritization process is investigated with different sintering temperature, and the prolonged leaching test. The thermal behavior, structural morphology, phase composition, and phase transformation of the stabilized sludge were investigated by using thermal gravimetry-differential scanning calorimetry, scanning electron microscopy and X-ray diffraction. The leaching behavior of the stabilized sludge under acidic environment was evaluated by modified Toxicity Characteristic Leaching Procedure (TCLP). The results indicated that CuFe(2)O(4) could be effectively formed at around 800°C by the iron oxide precursor with a 3h of short sintering. The transformation was discovered on crystallographic spinel structures: the low-temperature (800-900°C) tetragonal phase (t-CuFe(2)O(4)) and the high-temperature (∼ 1000°C) cubic phase (c-CuFe(2)O(4)). At higher temperatures (∼ 1100°C), the formation of cuprous ferrite delafossite phase (CuFeO(2)) from the dissociation of CuFe(2)O(4) was also noticed. Both CuFe(2)O(4) spinel and CuFeO(2) delafossite phase have a better intrinsic resistance to acidic environment when compared to that of CuO phase by the modified TCLP test. The sintering strategy designed for copper-laden sludge is proven to be beneficial in stabilizing copper.
Journal of hazardous materials 06/2011; 190(1-3):597-603. · 4.14 Impact Factor
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ABSTRACT: Electronic industrial wastewater sludge in Taiwan is normally passed through an acid-extraction process to reclaim most of the copper ions, the remaining residue may still need to be treated by various stabilization technologies using suitable additives. Cement solidification is used as the common method to stabilize the industrial wastewater sludge in Taiwan. However, this method has the disadvantage of an increase in waste volume. In the present study selective additives such as sodium sulfide, barium manganate and different phase of alumina were tested as a possible alternate additive to stabilize the heavy metal ion in the treated solid waste sludge via microwave heating treatment. The effects of additive amount, power of microwave irradiation and reaction time have been studied. Heavy metal leaching capacity is determined by using standard toxicity characteristic leaching procedure test and elemental content in the leachate is analyzed by inductively coupled plasma analysis. Sodium sulfide is effectively stabilizing the leaching copper ion with high selectivity in the presence of microwave irradiation and finally stabilized in the form of copper sulfide, which is a significant reaction to stabilize the copper ion leaching in the waste sludge. Complete stabilization of heavy metal ion and copper ion content (<5mgL(-1)) in industrial sludge is achieved by heating the microwave treated barium manganate and alumina additives by adopting suitable reaction conditions. Hybrid microwave and conventional heating process with minor amount of additive providing the efficient heavy metal stabilization for treated electronic industry waste sludge.
Chemosphere 11/2009; 78(5):609-13. · 3.21 Impact Factor
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ABSTRACT: A sintering with a microwave process was considered to stabilize copper-contaminated sludge and transform it into a sinter because microwave can provide uniform and quick heating. The parameters of addition of iron powder and ferric oxide, crucible modification, and air-forced leading were used in the microwave sintering. The results showed that reduced copper was present and some holes, caused by the high copper-contaminated synthetic sludge passing through the microwave sintering, were distributed throughout the sinters. However, when microwave sintering with the modification of parameters (improved microwave sintering) was used, the phenomena of copper reduction and hole formation were dispelled. Moreover, the improved microwave sintering of synthetic sludge with iron powder at 800W at 30 min formed cuprospinel with peaks of 2theta degrees of 18.508 and 57.05 shifting to 18.9 and 56.55 and the leaching concentration from this sinter passed the limit of toxicity characteristic leaching procedure (TCLP) for copper.
Journal of hazardous materials 04/2009; 168(2-3):857-61. · 4.14 Impact Factor
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ABSTRACT: Out of reputation and audit risk considerations, the incumbent auditor may not be willing to accommodate the unreasonable request from the client with deteriorating financial conditions. On the other hand, the client may switch the auditor to solicit a clean audit opinion from the successive auditor. Viewed from such a perspective, the main proposition is that firms with auditor change subsequently have a higher probability of incurring financial distress. The main proposition has gained strong empirical support in alternative estimation models. The authors therefore conclude that the incorporation of the variable 'auditor change' can greatly enhance the predictive power of previous financial distress prediction models.
Applied Financial Economics. 01/2009; 19(1):59-72.
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ABSTRACT: The present study examines the introduction of partial auction on speed of price adjustment in the Initial Public Offering's (IPO) aftermarket in Taiwan. From a paired comparison between before/after introducing partial auction sub-samples of the IPO firms, as expected, it is found that the average trading days of stock prices needed for reaching equilibrium is significantly smaller in the 'issues after introducing partial auction' sub-period, when compared with the 'issues before introducing partial auction' sub-period. Within the post-partial-auction sub-period, it is found that the average trading days of stock prices needed for reaching equilibrium is somewhat smaller in the 'issues with partial auction' subgroup when compared with the 'issues without partial auction' subgroup, but, when the observation period is extended to 3 months, the difference as expected disappears. More importantly, the average number of days of completing adjustment for both 'issues with partial auction' and 'issues without partial auction' subgroups are shortened as a result of the introduction of partial auction when compared with their counterpart in the pre-partial-auction sub-period. When 'firm size' and 'book-to-market ratio' are added in company with three other explanatory variables in a regression analysis, the inference that the introduction of the partial auction speeds up the price adjustment in the aftermarket remains intact. The present study therefore concludes that the speed of adjustment quickens after introducing auctions mechanism into Taiwan IPO market.
Applied Financial Economics. 01/2009; 19(8):669-680.
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ABSTRACT: This study presents the sintering of municipal solid waste incineration (MSWI) fly ash assisted by microwave energy. The composition of fly ash was investigated by chemical sequential extraction and modified microwave digestion method. Effects of process time, container materials, aging time and salt contents were also discussed. The major elements of fly ash are Ca, Cl, Na, Si, K, Al, Mg, and Zn, and the metal species, Zn, Cr, Pb, Ca, and Cu, are mainly in the oxide phase. Under microwave processing, the fly ash was sintered into a glass-ceramics and the leaching concentrations of heavy metals were restrained. The stabilization efficiency increased with an increase in processing time in most of the cases. Better stabilization efficiency of fly ash was discovered by using the SiO(2) or Al(2)O(3) container than by using the graphite plate/SiC plate. The presence of salt in the fly ash could enhance the sintering and stabilization of fly ash. During the aging time of 0-30 days, negligible Pb in the sintered fly ash was leached out, and the leaching concentration was lower than the criterion.
Journal of Hazardous Materials 08/2008; 163(1):357-62. · 4.17 Impact Factor
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ABSTRACT: Industrial wastewater sludge was treated by microwave processes to enhance the stabilization of laden copper. The effects of additives, processing time, microwave adsorbents, moisture content, reaction atmosphere, and cooling gas were investigated. The stabilization results were significantly enhanced by metal powder additives, prolonged microwave processing time, proper moisture content, the addition of carbonaceous materials, and a reaction environment with inert gas. It was also found that the moisture content would increase the homogeneity of applied microwave energy, and thus achieve a better overall efficiency between stabilizing agents and copper. The added metal powders may reduce Cu(II) to Cu(0) in the sludge or TCLP. The resulting thermal energy of microwave radiation, and microarcing process and the oxidation heat of Al powder may also assist the transformation of Cu(II) into CuO and CuAl2O4 phases. Part of the sludge was vitrified within inert gas environment when the processing time was longer than 18 min and active carbon dosage was more than 3g. Reduction reactions also occurred in the hybrid microwave processes, leading to the reduction of sulfates and metal ions, and the formation of Cu2S and FeS. Moreover, the microwave radiation can also enhance the feasibility of co-treating of inorganic and organic solid waste.
Chemosphere 05/2008; 71(9):1693-700. · 3.21 Impact Factor
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ABSTRACT: After industrial wastewater sludge passed through an acid-extraction process to reclaim most of the copper ions in it, the residue may still need to be treated by stabilization technologies. The common method for the stabilization of hazardous waste in Taiwan is by cement solidification. However, this method has the disadvantage of an increase in waste volume. In this study, it was tried to combine the advantages of sulfur anions and phosphate anions with the characteristics of microwave energy to offer a new method which can avoid the disadvantage of cement solidification. From the results, it was found that the assistance of heating in sludge stabilization with additives was effective. Huge amounts of additives were saved. Compared with the assistance of the traditional electrical-heating in sludge stabilization with additives, that of the microwave process saved much time and was more powerful. However, when the reaction time was longer, a re-leaching situation would occur. The hybrid microwave process, a procedure of leading an inert gas into the microwave process, could overcome the disadvantage of the microwave process with regard to the long reaction time. Finally, a modified hybrid microwave process which reduced the use of gas was performed and recommended.
Journal of Hazardous Materials 09/2007; 147(3):930-7. · 4.17 Impact Factor
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ABSTRACT: A microwave process can be utilized to stabilize the copper ions in heavy metal sludge. The effects of microwave processing on stabilization of heavy metal sludge were studied as a function of additive, power, process time, reaction atmosphere, cooling gas, organic substance, and temperature. Copper leach resistance increased with addition of aluminum metal powder, with increased microwave power, increased processing time, and using a gaseous environment of nitrogen for processing and air for cooling [N2/air]. The organic in the sludge affected stabilization, whether or not the organic smoldered. During heating in conventional ovens, exothermic oxidation of the organic resulted in sludge temperatures of about 500 degrees C for oven control temperatures of 200-500 degrees C. After microwave heating dried the sludge, the sludge temperature rose to 500 degrees C. The reaction between copper ions and metal aluminum in the dried sludge should be regarded as a solid phase reaction. Adding aluminum metal powder and reaction temperature were the key parameters in stabilizing copper in the heavy metal sludge, whether heated by microwave radiation or conventional oven. The mass balance indicates insignificant volatization of the copper during heating.
Journal of Hazardous Materials 02/2007; 139(1):160-6. · 4.17 Impact Factor
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ABSTRACT: Microwave stabilized heavy metal sludge was used as an adsorbent to remove the copper ions from aqueous solution. The adsorption characteristics of copper on the stabilized-sludge were studied by various models, such as Freundlich and Langmuir isotherm equation. Results show that the pH(zpc) of stabilized-sludge was at 9.2-9.5. Moreover, the adsorption of copper ions onto the stabilized-sludge surface was mainly on account of the heterogeneous surface of the stabilized-sludge. In the dynamic study, the experimental data was fitted to the intraparticle diffusion model, pseudo-first order model and pseudo-second order model. However, the experimental data was only well correlated with pseudo-second order model with the correlation coefficient>0.995. Furthermore, both Freundlich and Langmuir isotherm equations were found to represent the measured adsorption data well. From the Langmuir equation, the adsorption capacity increased from 18 to 28 mg/g as the temperature rose from 15 to 55 degrees C, since this adsorption process was an endothermic reaction. After this adsorption process, copper ions can be concentrated on and in a small bead and recovery efficiently.
Journal of Hazardous Materials 08/2006; 136(2):338-44. · 4.17 Impact Factor
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ABSTRACT: The leaching concentration of copper ions from the industrial sludge that has been extracted using sulfuric acid may still exceed 15 mg/L, which is the leaching standard of the toxicity characteristic leaching procedure (TCLP) for hazardous waste in Taiwan. Therefore, the acid-extracted industrial sludge is still an important source of hazardous waste. Usually, hazardous waste in Taiwan must be solidified and passed through the TCLP test before it is disposed in a landfill. The aim of this study is to develop a microwave process to stabilize copper ions in the sludge to replace the use of traditional solidification. In this study, two parameters--the reaction time of the microwave process and the additive reagents--were considered. The efficiency of stabilization of the microwave process was evaluated from the result of the TCLP test. The results showed that the stabilization efficiency of copper ions obtained using a microwave process without any added reagent depends highly on the property of the original acid-extracted sludge. Under some conditions, the leaching concentrations were much lower than those of the raw sludge. In additive reagent systems, the results showed that iron powder promoted the stabilization of copper ions more than the other additives such as sodium carbonate and sodium silicate. The leaching concentration of copper ions decreased dramatically from 179.4 to 6.5mg/L below in the iron additive system.
Journal of Hazardous Materials 09/2005; 123(1-3):256-61. · 4.17 Impact Factor
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ABSTRACT: In a previous study based on a matched sample analysis, it is found that in Taiwan top management turnover rate for the listed firms in the presence of a proxy contest is much higher than the ones without a proxy contest. In other words, the hypothesis of job security has gained empirical support. Taking account of the proxy contest outcomes, the present study extends the sample years, i.e. 1994-1999, to further examine the impact of proxy contest on managerial turnover. In conformity with expectations, the major empirical findings can be summarized as follows: the highest turnover rate of top management is observed in the firms of which the dissidents win majority seats; the second highest turnover rate is observed in the firms of which the dissidents win some seats; whereas the lowest turnover rate is observed in the firms of which the dissidents win no seats. Empirical findings of this kind provide further support to the view that proxy contest has played an effective monitoring role in disciplining incumbent management. Copyright © 2004 John Wiley & Sons, Ltd.
Managerial and Decision Economics 02/2005; 26(1):15-23.
