C C Wang

Chang Gung Memorial Hospital, T’ai-pei, Taipei, Taiwan

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Publications (52)62.59 Total impact

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    ABSTRACT: Adipose-derived mesenchymal stem cells (ASCs) have been considered to be attractive and readily available adult mesenchymal stem cells (MSCs) and are becoming increasingly popular for use in regenerating cell therapy. However, recent evidence attributed a fibrotic potential to MSCs which differentiated into myofibroblasts with highly increased α-smooth muscle actin (α-SMA) expression while transplanted into an injured/regenerating liver in mice. In this study, we studied the role of miR-27b in ASCs and their regenerative potential after partial liver resection in rats. ASCs transfected with control siRNA or miR-27b were intravenously injected into autologous rats undergoing 70% partial hepatectomy (PH). Our data showed that the regenerative capacities of ASCs with overexpressed miR-27b were significantly higher compared with control ASCs. However, the enhanced regeneration, hepatic differentiation, and suppressed liver inflammation, as well as fibrotic activity, were significantly reverted by ZnPP coadministration (heme oxygenase-1 [HO-1] inhibitor) indicating an important role of HO-1 in the regenerating and cytoprotective activities of miR-27b–transfected ASCs. We demonstrated that administration of autologous ASCs overexpressed with miR-27b enhances rapid and early liver regeneration and, importantly, preserves function after PH. The ASCs with miR-27b overexpression might offer a viable therapeutic option to facilitate rapid recovery after liver resection.
    Transplantation Proceedings 01/2014; 46(4):1198–1200. · 0.95 Impact Factor
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    ABSTRACT: The aim of this study was to evaluate portal vein stenosis (PVS) in pediatric liver transplantation (PLT) using Doppler ultrasound (DUS) before and after interventional management for hemodynamic changes. From 2000 to 2010, we encountered 11 PVS cases among 180 PLT that were evaluated using DUS and computed tomography (CT) angiography (CTA); all underwent portal stenting. DUS was used to monitor portal hemodynamics. For the diagnosis of PVS, we investigated multiple parameters including stenotic size (SS), stenotic ratio (SR) (SR [%]=PRE-SS/PRE [PRE=stenotic size]), portal flow velocity ratio (VR) (VR=VS/PRE [PRE=velocity at prestenotic site; VS=peak velocity at stenotic site]), spleen size, and platelet count. The incidence of PVS was 5.6% (11/180). The PV was 2.5 mm using DUS and 2.7 mm using CTA. The average SR was 65% fitting the criterion. Low prestenotic portal flow<12 cm/sec and high peak velocity in the stenotic segment (up to 147 cm/sec) were observed in 6 cases. The VR value was high at 7.5:1 and there was splenomegaly with thrombocytopenia. After portal vein stenting, hyperperfusion occurred might after reopening the stenosis: the flow increased to an average of 34 cm/sec and then flow decreased slowly to a stable level 2 weeks later. The size of the spleen decreased from 17 to 12 cm and the thrombocytopenia also improved with platelet counts increasing from 67×10(3) to 178×10(3)/μl at 2 months follow-up. The changes in portal flow, portal vein size, spleen size, and platelet count were significant (P<.05). PVS is diagnosed using DUS by increased intrahepatic PV dilatation, peak flow at the stenotic site, discrepant VR. Early portal stenting showed a better prognosis. DUS is essential and effective for hemodynamic monitoring and management of PVS.
    Transplantation Proceedings 03/2012; 44(2):481-3. · 0.95 Impact Factor
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    ABSTRACT: To evaluate the postoperative portal vein stenosis (PVS) and the diagnostic efficiency of Doppler ultrasound (DUS) in adult living donor liver transplantation (ALDLT). From January 2007 to December 2008, 103 ALDLTs were performed and postoperatively followed by routine DUS. The morphologic narrowing at the anastomotic site (AS) of the PVS was analyzed. We calculated the PV stenotic ratio (SR) using the following formula: SR (%)=PRE-AS/PRE (PRE=pre-stenotic caliber). An SR>50% was defined as the critical point for PVS. We also calculated the velocity ratio (VR) between the AS and PRE, and set the significant VR as >3:1. Statistical analyses were carried out to determine clinical significance. Using the definition of morphologic PVS by DUS, there were total 20 cases (19.4%) in this series with SR>50%, which included 17 cases with VR>3:1. Eight cases of severe PVS had a stenotic AS>5 mm and subsequently underwent interventional management. Doppler criteria of SR and VR values were elevated up to 75.8% and 7.5:1, respectively, in these treated cases. Two cases of severe PVS subsequently developed PV thrombosis. Intervention by balloon dilation and/or stenting was performed successfully in this PVS case. DUS is the most convenient and efficient imaging modality to detect and follow postoperative PVS in ALDLT. The Doppler criteria of SR and VR are both sensitive but less specific. Cases of AS<5 mm require interventional management for good long-term graft survival.
    Transplantation Proceedings 04/2010; 42(3):879-81. · 0.95 Impact Factor
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    ABSTRACT: The impact of strain induced oxide trap charge on the performance and reliability of contact etch stop SiN layer capped, fully silicided metal gate, fully depleted SOI (FDSOI) CMOSFET is investigated. For an ultra thin nitride oxide, the position of these oxide trap charge can be evaluated by variable frequency noise spectrum and variable frequency charge pumping technique. Gate oxide film bending caused by net stress from these strain technologies was considered as the main reason for bulk oxide trap charge formation. We find that a strained SOI MOSFET with a thinner SOI is more subjective to the stress than the thicker one, and the thinner SOI device possesses a higher oxide/Si interface trap charge density which will degrade the channel mobility. On the other hand, more bulk oxide trap, which existed in the strained device having a thicker SOI, was the dominate factor on current/voltage stress induced device degradation. Introduction With aggressive MOSFET scaling toward the 45nm node and beyond, FET fabricated on the silicon on insulator substrate with a very thin silicon thickness (so-called the fully depleted SOI, FDSOI) is a promising candidate to improve the subthreshold swing and reduce the off-state leakage (I D @V G =0V). However, mobility degradation due to the phonon scattering and threshold voltage V T stability must be minimized. Some strain technologies were implemented to improve MOS device's driving capability [1], such as the contact etch stop SiN layer (CESL) which is a process-compatible choice especially for nFET in terms of reliability and performance [2]. Metal gate such as the fully silicided (FUSI) gate electrode was employed [3] to improve V T stability, increase conductivity and enhance inversion charge density [4]. However, there are very few studies on the impact of oxide trap charge induced from the strain technology on FUSI gate FDSOI MOFET performance especially for reliability. In this work, we will investigate the strain induced oxide/Si interface and bulk oxide traps and their impact on the FDSOI MOSFET characteristic and reliability. For ultra thin nitride oxide (EOT~15Å), the location of oxide trap charge is very difficult to identify, but it can be evaluated by variable frequency noise spectrum analysis and variable frequency charge pumping technique. With CESL capped, we find that channel mobility can be improved effectively in thinner SOI device but with extra strain induced oxide/Si interface trap charge induced. The bulk oxide trap charge possible caused by gate oxide film bending especially those in thicker SOI device will enhance post current/voltage stress induced device degradation (hot carrier effect HCE and negative/positive bias temperature instability N/PBTI).
    12/2009;
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    ABSTRACT: We sought to compare the effects of operation room temperature (ORT) at typical ambient environment (19-21 degrees C) and ORT at 24 degrees C on the core temperature of patients undergoing living donor hepatectomy. Sixty-two patients undergoing living donor hepatectomy were divided into 2 groups. In group I (n = 31), surgery was performed at typical ambient ORT, and in group II (n = 31) in ORT at 24 degrees C. Anesthesia and measures to prevent heat loss, except ORT, were all the same. Nasopharyngeal temperature (NT) was recorded after anesthesia induction, then hourly until completion of the operation. Changes in NTs were analyzed as well as patient age, weight, anesthetic duration, blood loss, intravenous fluids, total urine output, and pre- and postoperative hemoglobin and hematocrit values. The Mann-Whitney U test was used for comparisons between groups. The patient's characteristics between groups were not statistically different. However, a significantly higher core temperature was noted in group II compared with group I. Increased ORT from 19 to 21 degrees C to 24 degrees C resulted in an increased core temperature of at least 0.5 degrees C during living donor hepatectomy.
    Transplantation Proceedings 11/2008; 40(8):2463-5. · 0.95 Impact Factor
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    ABSTRACT: ObjectiveEarly diagnosis and appropriate management of vascular and biliary complications after living donor liver transplantation (LDLT) result in longer survival. We report our institutional experience regarding radiological management of these complications among patients with biliary atresia (BA) who underwent LDLT.MethodsWe analyzed the records of 116 children. All patients underwent Doppler ultrasound (US) at operation, daily for the first 2 postoperative weeks, and when necessary thereafter. After primary evaluation using US, the definite diagnosis of postoperative complication was confirmed using computed tomography, magnetic resonance imaging, and/or operation.ResultsThere were 61 boys and 55 girls. The overall mean age was 2.69 years. The overall mean preoperative weight and height were 13.06 kg and 83.79 cm, respectively. There were 28 (24.13%) biliary and vascular complications. These were cases of biliary stricture (n = 5), bile leakage (n = 3), hepatic artery stenosis (n = 6), hepatic vein stenosis (n = 4), and portal vein thrombosis (n = 17). The diagnostic accuracy of US in detecting biliary complication, hepatic artery stenosis, hepatic venous stenosis, and portal vein thrombosis was 95.69%, 97.41%, 100%, and 100%, respectively. US in combination with multiple imaging modalities and clinical suspicion resulted in 100% diagnostic accuracy. Percutaneous transhepatic cholangiography, thrombolysis, balloon angioplasty, and stent placement were performed for the complications noted. There was an early mortality due to multiple-organ failure after failed radiological invention and subsequent surgical management.ConclusionsDoppler US is accurate in detecting postoperative complications after pediatric LDLT for BA. Radiological interventions for vascular and biliary complications are effective and safe alternatives to reconstructive surgery.
    Transplantation Proceedings 11/2008; · 0.95 Impact Factor
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    ABSTRACT: The purpose of this study was to assess factors influencing the end-tidal concentrations of isoflurane within a bispectral index (BIS) range of 45–55 among healthy live liver donors (n = 11), chronic hepatitis B patients undergoing hepatectomy hepatocellular carcinoma (n = 10), and end-stage liver disease patients undergoing liver transplantation (n = 7). Patients data collected prospectively were compared among the groups using one-way analysis of variance as well as univariate and multivariate techniques. The results showed that end-stage liver disease patients required the least end-tidal isoflurane concentration. Patients with hepatocellular carcinoma with cirrhosis required intermediate end-tidal isoflurane concentrations; healthy live liver donors required the highest end-tidal isoflurane concentrations to provide sufficient anesthetic depth, as monitored by a target BIS (range, 45–55). Upon multivariate analysis, liver function was the only significant factor influencing the likelihood of lowering the end-tidal isoflurane concentration by 4 hours after anesthesia induction (P = .026). In conclusion, we recommend a preset target BIS within the range of 45–55 to monitor the depth of anesthesia during partial hepatectomy and liver transplantation because end-tidal isoflurane concentration requirements are different for patients with various liver status. This strategy may protect the patients from intraoperative recall or anesthesia over-depth as a consequence of insufficient or overdose of anesthesia, respectively.
    Transplantation Proceedings 11/2008; · 0.95 Impact Factor
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    ABSTRACT: Portal hyperperfusion in a small-size liver graft is one cause of posttransplant graft dysfunction. We retrospectively analyzed the potential risk factors predicting the development of portal hyperperfusion in 43 adult living donor liver transplantation recipients. The following were evaluated: age, body weight, native liver disease, spleen size, graft size, graft-to-recipient weight ratio (GRWR), total portal flow, recipient portal venous flow per 100 g graft weight (RPVF), graft-to-recipient spleen size ratio (GRSSR) and portosystemic shunting. Spleen size was directly proportional to the total portal flow (p = 0.001) and RPVF (p = 0.014). Graft hyperperfusion (RPVF flow > 250 mL/min/100 g graft) was seen in eight recipients. If the GRSSR was < 0.6, 5 of 11 cases were found to have graft hyperperfusion (p = 0.017). The presence of portosystemic shunting was significant in decreasing excessive RPVF (p = 0.059). A decrease in portal flow in the hyperperfused grafts was achieved by intraoperative splenic artery ligation or splenectomy. Spleen size is a major factor contributing to portal flow after transplant. The GRSSR is associated with posttransplant graft hyperperfusion at a ratio of < 0.6.
    American Journal of Transplantation 12/2006; 6(12):2994-9. · 6.19 Impact Factor
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    ABSTRACT: Photooxidation of azo dye Reactive Black 5 (RB5) by H202 was performed with a novel supported iron oxide in a batch reactor in the range of pH 2.5-6.0. The iron oxide was prepared through a fluidized-bed reactor (FBR) and much cheaper than the Nafion-based catalysts. Experimental results indicate that the iron oxide can significantly accelerate the degradation of RB5 under the irradiation of UVA light (wavelength = 365 nm). An advantage of the catalyst is its long-term stability, which was confirmed through using the catalyst for multiple runs in the degradation of RB5. In addition, this study focused mainly on determining the proportions of homogeneous catalysis and heterogeneous catalysis in the batch reactor. Conclusively, although heterogeneous catalysis contributes primarily to the oxidation of RB5 during pH 4.5-6.0, the homogeneous catalysis is of increasing importance below pH 4.0 because of the Fe ions leaching from the catalyst to solution.
    Water Science & Technology 02/2006; 53(6):195-201. · 1.10 Impact Factor
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    ABSTRACT: The color Doppler ultrasound has been used to evaluate hepatic vein (HV) outflow insufficiency based on flow velocity and waveforms. In our experience, some cases with flat waveforms are clinically asymptomatic. The parameters of HV flow velocity and waveforms are not always correlated with clinical problems. So, we proposed that total HV flow volume (HVFV) may be a more reliable index. From August 2001 to July 2003, 31 cases among 48 adult-to-adult living related transplants of a right liver graft had one HV anastomosis. HV velocity, waveforms, and HVFV were compared both before and after transplantation. We set the minimal HVFV ratio at 80% based on the original HVFV before graft retrieval. There was no significant difference in HVFV before liver graft retrieval between the 2 groups, but there was a significant change after transplantation. There were no cases of HV insufficiency among group A patients (>80%), whose HVFV ranged from 397 to 1181 mL/min with ratios from 75% to 180% (mean 115%). In group B, there were 4 complicated cases with prolonged severe ascites (<80%) with HVFV ratios from 56% to 76% (mean 66%). Fisher exact test showed a great significance (P < .001). Thus the preliminary criteria of 80% minimal HVFV ratio allows detection of HV insufficiency for further interventional management.
    Transplantation Proceedings 03/2005; 37(2):1115-6. · 0.95 Impact Factor
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    ABSTRACT: A high linearity, high efficiency 1.9 GHz power amplifier sub-system using a 50 mm AIGaAs/InGaAs/GaAs PHEMT for PHS 500 mW base station is demonstrated. Under 10 V and 3.8 A bias condition, the output stage amplifier has achieved 12.5 dB small-signal gain, 43.7 dBm PldB with 43% PAE and 44 dBm saturated output power with 41% PAE. For the amplifier sub-system, the ACPR at 600 KHz and 900 KHz offset from 1.906 GHz when operating at 38.5 dBm output power with Π/4-DQPSK signal are better than 75 dBc and 79 dBc, respectively.
    Circuits and Systems, 2004. Proceedings. The 2004 IEEE Asia-Pacific Conference on; 01/2005
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    ABSTRACT: A X-band 8-watt AlGaAs/InGaAs/GaAs PHEMT MMIC power amplifier for the active phase radar applications is demonstrated. This amplifier is designed to fully match 50 ohm input and output impedance. With 8 volts and 850 mA DC bias condition, 17.5 dB small-signal gain, 39.3 dBm (8.5 watt) 2-dB gain compression power with 33.7% power-added efficiency and 40 dBm (10 watt) saturation power from 9.3 to 10.4 GHz can be achieved.
    Compound Semiconductor Integrated Circuit Symposium, 2004. IEEE; 11/2004
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    ABSTRACT: Hepatic outflow insufficiency remains one of the major complications causing postoperative graft failure especially among partial liver graft transplantations (PLT) including living donor liver transplantation (LDLT), reduced size liver transplantation (RLT), and split liver transplantation (SLT). These procedures are different from the whole liver graft transplantations (OLT), which include multiple vascular anastomoses. Color Doppler ultrasound (CDUS) was used to evaluate the hepatic venous outflow from grafts before and after radiological interventional management and to document treatment effects. From June 1994 to March 2003, our 136 cases of PLTs included 131 LDLTs, two RLTs, and three SLTs. Seven cases (six children and one adult) showed postoperative hepatic vein outflow obstruction and persistent massive ascites, as detected by color Doppler ultrasound (CDUS) and confirmed by interventional angiography. The CDUS showed a monophasic flat waveform with a relatively low hepatic vein average peak velocity (Va) in all cases (mean 11 cm/s). Successful interventional procedures included balloon dilatation in three cases and metallic stent replacement in four cases. CDUS was used with guidance during the procedure to confirm restoration of normal hepatic vein flow with a multiphasic waveform and an objective increase of average flow velocity (high to average 66 cm/s). Ascites disappeared dramatically after the procedure. In conclusion CDUS is the prime modality to diagnose and document a treatment response.
    Transplantation Proceedings 11/2004; 36(8):2342-3. · 0.95 Impact Factor
  • Journal of Pediatric Gastroenterology and Nutrition - J PEDIAT GASTROENTEROL NUTR. 01/2004; 39(2).
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    ABSTRACT: A He plus reactive ion etching technology for selective etching GaAs/AlGaAs has been developed, for the first time. Etching selectivity was studied with SEM under different RF power, pressure, and reactant gases. Experimental results show the selectivity between GaAs and AlGaAs can be raised from 90 without He to 150 with He plus. Modeling has been proposed to interpret the improving mechanism.
    Materials Science in Semiconductor Processing - MATER SCI SEMICOND PROCESS. 01/2004; 7(1):59-62.
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    ABSTRACT: In this paper, a 1.9 GHz watt high power amplifier using AlGaAs/InGaAs/GaAs PHEMT device for PHS base station applications is demonstrated. This amplifier utilizes a pre-matched FET which is composed of only a single 50 mm FET device and a MIS capacitor in a CuW flange package with other matching circuits on the FR4 PCB. Under 10 Volts and a 4 A dc bias condition, the amplifier has achieved 12.5 dB small-signal gain, 43.7 dBm 1 dB gain compression power with 43% power-added efficiency (PAE) and 44 dBm saturated output power with 41% PAR. In addition, high linearity with 53 dBm third-order intercept point is achieved. The ACP at 600 KHz offset from 1.906 GHz when operating at 39 dBm output power with π/4-DQPSK signal is better than 71 dBc.
    Electron Devices for Microwave and Optoelectronic Applications, 2003. EDMO 2003. The 11th IEEE International Symposium on; 12/2003
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    Transplantation Proceedings 03/2003; 35(1):68-9. · 0.95 Impact Factor
  • Transplantation Proceedings 03/2003; 35(1):62-3. · 0.95 Impact Factor
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    Transplantation Proceedings 03/2003; 35(1):55-6. · 0.95 Impact Factor
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    ABSTRACT: An enhancement-mode pseudomorphic high electron mobility transistor using optimum reactive ion etching (RIE) technology without damaging 2-D channel has been developed, at the first time. By using the optimum RIE recipe, the selectivity between GaAs and AlGaAs is more than 150. In addition, the maximum transconductance of the device with the dimension of reaches 235 ms/mm at Vds=1.4 V. Furthermore, at 12 GHz, the output power and gain can achieve 17.9 dBm and 14.03 dB respectively. Operating at 12 GHz, the noise figure at Vds=4 V is down to 0.65 dB which is comparable to low noise depletion-mode device.
    Solid-State Electronics 01/2003; · 1.48 Impact Factor

Publication Stats

348 Citations
62.59 Total Impact Points

Institutions

  • 1997–2014
    • Chang Gung Memorial Hospital
      • • Department of Surgery
      • • Department of Diagnostic Radiology
      • • Department of Pathology
      T’ai-pei, Taipei, Taiwan
  • 1998–2006
    • Chang Gung University
      Hsin-chu-hsien, Taiwan, Taiwan
    • Chang Gung University of Science and Technology
      Kao-hsiung-shih, Kaohsiung, Taiwan
  • 2002–2005
    • National Cheng Kung University
      • • Institute of Microelectronics
      • • Department of Electrical Engineering
      Tainan, Taiwan, Taiwan