Hepatitis C virus (HCV) genotype is an important criteria in determining duration of therapy and ... more Hepatitis C virus (HCV) genotype is an important criteria in determining duration of therapy and predictor of sustained virologic response (SVR) to pegylated interferon (PEG IFN) and ribavirin (RBV) therapy. Optimal duration of therapy for patients with HCV genotype 6 is not known. We conducted a multicenter, open-label randomized controlled trial of patients with HCV genotype 6 at five gastroenterology clinics in the western U.S. Patients were stratified by viral load and histologic stage and assigned to receive PEG IFN-α2a 180 μg subcutaneously weekly and weight-based oral RBV 800 to 1,200 mg daily for 24 or 48 weeks. Primary outcome measurement was SVR rate by intention-to-treat analysis. From February 2005 to October 2007 a total of 60 patients (age 51 ± 10 years, 47% male, log HCVRNA 6.3 ± 1.1 IU/mL) were enrolled: 27 patients to 24 weeks and 33 patients to 48 weeks of therapy. In the 24-week and 48-week groups, 96% and 97% achieved early virologic response (P = 0.90); 89% versus 94% achieved end of therapy virologic response (P = 0.48). SVR was achieved in 70% versus 79% of patients assigned to 24 weeks versus 48 weeks (P = 0.45). Rapid virologic response (RVR) was a significant predictor of SVR in the 48-week group and trending towards significance in the 24-week group: 82% and 83% of those with RVR achieved SVR versus 33% and 29% for the 24-week and 48-week groups, respectively (P = 0.07 and P = 0.02). Conclusion: There was no significant difference in SVR rates in patients with HCV genotype 6 treated with PEG IFN-α2a and RBV for 24 versus 48 weeks. (HEPATOLOGY 2010;52:1573-1580)
Today computers cannot achieve their intended reliability in operating systems, application progr... more Today computers cannot achieve their intended reliability in operating systems, application programs, control programs, or commercial systems, such as nuclear power plant control, space shuttle reliability, etc., without employing redundancy. In this paper, we describe a specific model for the emergency telecommunications system. We derive an expression to determine the reliability and the mean time to failure of the emergency telecommunications system with its mechanical switches and their two types of failure modes
Diarrhea continues to be one of the most common causes of morbidity and mortality among infants a... more Diarrhea continues to be one of the most common causes of morbidity and mortality among infants and children in developing countries. Escherichia coli is an emerging agent among pathogens that cause diarrhea. The development of a highly applicable technique for the detection of different categories of diarrheagenic E. coli is important. We have used multiplex PCR by combining eight primer pairs specific for enteroaggregative E. coli (EAEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. coli, enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC). This facilitates the identification of five different categories of diarrheagenic E. coli from stool samples in a single reaction simultaneously. The prevalences of diarrheagenic E. coli were 22.5 and 12% in the diarrhea group and the control group, respectively. Among 587 fecal samples from Vietnamese children under 5 years of age with diarrhea, this technique identified 132 diarrheagenic E. coli strains. This included 68 samples (11.6%) with EAEC, 12 samples (2.0%) with EIEC, 39 samples (6.6%) with EPEC, and 13 samples (2.2%) with ETEC. Among the 249 age-matched controls, 30 samples were positive for diarrheagenic E. coli. The distribution was 18 samples (7.2%) with EAEC, 11 samples (4.4%) with EPEC, and 1 sample (0.4%) with ETEC.
We investigated the electronic structure and lattice dynamics of multiferroic MnWO4 by optical sp... more We investigated the electronic structure and lattice dynamics of multiferroic MnWO4 by optical spectroscopy. With variation of polarization, temperature, and magnetic field, we obtained optical responses over a wide range of photon energies. The electronic structure of MnWO4 near to the Fermi level was examined, with inter-band transitions identified in optical conductivity spectra above a band-gap of 2.5 eV. As for the lattice dynamics, we identified all the infrared transverse optical phonon modes available according to the group-theory analysis. Although we did not observe much change in global electronic structure across the phase transition temperatures, an optical absorption at around 2.2 eV showed an evident change depending upon the spin configuration and magnetic field. The behavior of this band-edge absorption indicates that spin-orbit coupling plays an important role in multiferroic MnWO4.
Background Screening for hepatocellular carcinoma (HCC) has been shown to improve survival via ea... more Background Screening for hepatocellular carcinoma (HCC) has been shown to improve survival via earlier cancer detection. Although HCC screening is considered standard of care in the USA, little is known of the adherence to this practice, especially in a community setting. Aims Our primary goal was to evaluate adherence to HCC screening and to find predictors of screening adherence in a community setting. Our secondary objective was to determine the impact of screening on survival. Methods We studied a cohort of 557 consecutive patients at high risk for HCC: patients with cirrhosis and older chronic hepatitis B (CHB) patients without cirrhosis (≥45 years old). Patients initiated screening 1/2001–1/2005 and were monitored ≥12 months to 12/2008 in two community gastroenterology clinics in Northern California. HCC screening was categorized into four groups based on combined frequency of serum alpha-fetoprotein and imaging: optimal, suboptimal, poor, and no screening. Results About 40.6% of our cohort received poor or no screening. Noncirrhotic CHB patients had worse screening than cirrhotic patients. Multivariate analysis revealed that patients with a greater number of clinical visits per year were 3.4 times more likely to have regular screening than patients with fewer clinical visits per year (P Conclusion Since more frequent clinic visits is a strong independent predictor of improved screening adherence, regular routine clinic visits may help improve adherence to HCC screening, which may also lead to improved clinical outcomes.
The liver stiffness measurement is a novel method which allows to evaluate indirectly and noninva... more The liver stiffness measurement is a novel method which allows to evaluate indirectly and noninvasively the liver fibrosis stage. The reproducibility of the method in patients with different fibrosis stage and in the different weight groups is still under discussion. Aim. To evaluate the reproducibility of transient elastography in patients of different weight and fibrosis stage groups. Methods. The liver stiffness measurements were performed to 187 consecutive patients who suffered from chronic liver diseases using FibroScan (EchoSens, France) equipment. Not less than 22 measurements during the examination were performed to each patient. We analyzed an intra-observer agreement between results of two series by 11 measurements using Intraclass Correlation Coefficient (ICC). Results. There were no statistically significant differences between medians of two series of measurements (N=187, M±s 9.35±7.32 for the 1st series vs 9.22±7.98 for the 2nd series, p=0.27). The Intraclass Correlation Coefficient for two series of measurements was excellent ICC=0.9887, ]. There was no statistical difference between ICCs for two series of measurements in patients with an excessive weight (BMI≥25 kg/m2, N=88) and normal weight (BMI<25 kg/m2, N=99) -0.9865 (95% CI [0.9794-0.9911]) vs ICC=0.9900 (95% CI [0.9851-0.9931]), p=0.3122. The intraobserver coefficients for patients with different liver fibrosis stage were as follows: F0-1 -0.82 (N=107), F2 -0.61 (N=36), F3 -0.92 (N=13), F4 -0.98 (N=31). Conclusions: Transient elastography is a reproducible technique for assessing liver fibrosis in patients with chronic liver diseases. The intraobserver agreement does not significantly depend on the patients' weight. The reproducibility of transient elastography is lower in patients with mild liver fibrosis stages.
Capturing of odorous compounds such as toluene vapor by a particulate-activated carbon adsorbent ... more Capturing of odorous compounds such as toluene vapor by a particulate-activated carbon adsorbent was investigated in a gas-solid cyclone, which is one type of mobile beds. The test cyclone was early modified with the post cyclone (PoC) and a spiral flow guide to the vortex finder. The proposed process may contribute to the reduction of gases and dust from industrial exhausts, especially when dealing with a low concentration of odorous elements and a large volume of dust flow. In this device, the toluene capturing efficiency at a 400 ppm concentration rose up to 77.4% when using activated carbon (AC) particles with a median size of 27.03 μm. A maximum 96% of AC particles could be collected for reuse depending on the size and flow rate. The AC regenerated via thermal treatment showed an adsorption potential up to 66.7% throughout repeated tests.VOCs and particles have been of interest both in industrial field and public indoor spaces. In this study, a post cyclone (PoC) that utilizes a residual vortex from the mother cyclone was modified by inserting a flow guide and was applied to capture toluene vapor. The device of modified post-cyclone system can be used effectively in simultaneous treatment of gas-solid flow.
X-ray and γ-ray radiography have been indispensable techniques for materials inspection for many ... more X-ray and γ-ray radiography have been indispensable techniques for materials inspection for many years. Internal structure is typically inferred from radiographs by human evaluation. More precise information is possible if the function of three spatial variables can be estimated directly from the radiographic data. Several mathematical inversion formulae have been derived for deterministic reconstruction from the cone-beam integral projection data
Hepatitis C virus (HCV) genotype is an important criteria in determining duration of therapy and ... more Hepatitis C virus (HCV) genotype is an important criteria in determining duration of therapy and predictor of sustained virologic response (SVR) to pegylated interferon (PEG IFN) and ribavirin (RBV) therapy. Optimal duration of therapy for patients with HCV genotype 6 is not known. We conducted a multicenter, open-label randomized controlled trial of patients with HCV genotype 6 at five gastroenterology clinics in the western U.S. Patients were stratified by viral load and histologic stage and assigned to receive PEG IFN-α2a 180 μg subcutaneously weekly and weight-based oral RBV 800 to 1,200 mg daily for 24 or 48 weeks. Primary outcome measurement was SVR rate by intention-to-treat analysis. From February 2005 to October 2007 a total of 60 patients (age 51 ± 10 years, 47% male, log HCVRNA 6.3 ± 1.1 IU/mL) were enrolled: 27 patients to 24 weeks and 33 patients to 48 weeks of therapy. In the 24-week and 48-week groups, 96% and 97% achieved early virologic response (P = 0.90); 89% versus 94% achieved end of therapy virologic response (P = 0.48). SVR was achieved in 70% versus 79% of patients assigned to 24 weeks versus 48 weeks (P = 0.45). Rapid virologic response (RVR) was a significant predictor of SVR in the 48-week group and trending towards significance in the 24-week group: 82% and 83% of those with RVR achieved SVR versus 33% and 29% for the 24-week and 48-week groups, respectively (P = 0.07 and P = 0.02). Conclusion: There was no significant difference in SVR rates in patients with HCV genotype 6 treated with PEG IFN-α2a and RBV for 24 versus 48 weeks. (HEPATOLOGY 2010;52:1573-1580)
Today computers cannot achieve their intended reliability in operating systems, application progr... more Today computers cannot achieve their intended reliability in operating systems, application programs, control programs, or commercial systems, such as nuclear power plant control, space shuttle reliability, etc., without employing redundancy. In this paper, we describe a specific model for the emergency telecommunications system. We derive an expression to determine the reliability and the mean time to failure of the emergency telecommunications system with its mechanical switches and their two types of failure modes
Diarrhea continues to be one of the most common causes of morbidity and mortality among infants a... more Diarrhea continues to be one of the most common causes of morbidity and mortality among infants and children in developing countries. Escherichia coli is an emerging agent among pathogens that cause diarrhea. The development of a highly applicable technique for the detection of different categories of diarrheagenic E. coli is important. We have used multiplex PCR by combining eight primer pairs specific for enteroaggregative E. coli (EAEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. coli, enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC). This facilitates the identification of five different categories of diarrheagenic E. coli from stool samples in a single reaction simultaneously. The prevalences of diarrheagenic E. coli were 22.5 and 12% in the diarrhea group and the control group, respectively. Among 587 fecal samples from Vietnamese children under 5 years of age with diarrhea, this technique identified 132 diarrheagenic E. coli strains. This included 68 samples (11.6%) with EAEC, 12 samples (2.0%) with EIEC, 39 samples (6.6%) with EPEC, and 13 samples (2.2%) with ETEC. Among the 249 age-matched controls, 30 samples were positive for diarrheagenic E. coli. The distribution was 18 samples (7.2%) with EAEC, 11 samples (4.4%) with EPEC, and 1 sample (0.4%) with ETEC.
We investigated the electronic structure and lattice dynamics of multiferroic MnWO4 by optical sp... more We investigated the electronic structure and lattice dynamics of multiferroic MnWO4 by optical spectroscopy. With variation of polarization, temperature, and magnetic field, we obtained optical responses over a wide range of photon energies. The electronic structure of MnWO4 near to the Fermi level was examined, with inter-band transitions identified in optical conductivity spectra above a band-gap of 2.5 eV. As for the lattice dynamics, we identified all the infrared transverse optical phonon modes available according to the group-theory analysis. Although we did not observe much change in global electronic structure across the phase transition temperatures, an optical absorption at around 2.2 eV showed an evident change depending upon the spin configuration and magnetic field. The behavior of this band-edge absorption indicates that spin-orbit coupling plays an important role in multiferroic MnWO4.
Background Screening for hepatocellular carcinoma (HCC) has been shown to improve survival via ea... more Background Screening for hepatocellular carcinoma (HCC) has been shown to improve survival via earlier cancer detection. Although HCC screening is considered standard of care in the USA, little is known of the adherence to this practice, especially in a community setting. Aims Our primary goal was to evaluate adherence to HCC screening and to find predictors of screening adherence in a community setting. Our secondary objective was to determine the impact of screening on survival. Methods We studied a cohort of 557 consecutive patients at high risk for HCC: patients with cirrhosis and older chronic hepatitis B (CHB) patients without cirrhosis (≥45 years old). Patients initiated screening 1/2001–1/2005 and were monitored ≥12 months to 12/2008 in two community gastroenterology clinics in Northern California. HCC screening was categorized into four groups based on combined frequency of serum alpha-fetoprotein and imaging: optimal, suboptimal, poor, and no screening. Results About 40.6% of our cohort received poor or no screening. Noncirrhotic CHB patients had worse screening than cirrhotic patients. Multivariate analysis revealed that patients with a greater number of clinical visits per year were 3.4 times more likely to have regular screening than patients with fewer clinical visits per year (P Conclusion Since more frequent clinic visits is a strong independent predictor of improved screening adherence, regular routine clinic visits may help improve adherence to HCC screening, which may also lead to improved clinical outcomes.
The liver stiffness measurement is a novel method which allows to evaluate indirectly and noninva... more The liver stiffness measurement is a novel method which allows to evaluate indirectly and noninvasively the liver fibrosis stage. The reproducibility of the method in patients with different fibrosis stage and in the different weight groups is still under discussion. Aim. To evaluate the reproducibility of transient elastography in patients of different weight and fibrosis stage groups. Methods. The liver stiffness measurements were performed to 187 consecutive patients who suffered from chronic liver diseases using FibroScan (EchoSens, France) equipment. Not less than 22 measurements during the examination were performed to each patient. We analyzed an intra-observer agreement between results of two series by 11 measurements using Intraclass Correlation Coefficient (ICC). Results. There were no statistically significant differences between medians of two series of measurements (N=187, M±s 9.35±7.32 for the 1st series vs 9.22±7.98 for the 2nd series, p=0.27). The Intraclass Correlation Coefficient for two series of measurements was excellent ICC=0.9887, ]. There was no statistical difference between ICCs for two series of measurements in patients with an excessive weight (BMI≥25 kg/m2, N=88) and normal weight (BMI<25 kg/m2, N=99) -0.9865 (95% CI [0.9794-0.9911]) vs ICC=0.9900 (95% CI [0.9851-0.9931]), p=0.3122. The intraobserver coefficients for patients with different liver fibrosis stage were as follows: F0-1 -0.82 (N=107), F2 -0.61 (N=36), F3 -0.92 (N=13), F4 -0.98 (N=31). Conclusions: Transient elastography is a reproducible technique for assessing liver fibrosis in patients with chronic liver diseases. The intraobserver agreement does not significantly depend on the patients' weight. The reproducibility of transient elastography is lower in patients with mild liver fibrosis stages.
Capturing of odorous compounds such as toluene vapor by a particulate-activated carbon adsorbent ... more Capturing of odorous compounds such as toluene vapor by a particulate-activated carbon adsorbent was investigated in a gas-solid cyclone, which is one type of mobile beds. The test cyclone was early modified with the post cyclone (PoC) and a spiral flow guide to the vortex finder. The proposed process may contribute to the reduction of gases and dust from industrial exhausts, especially when dealing with a low concentration of odorous elements and a large volume of dust flow. In this device, the toluene capturing efficiency at a 400 ppm concentration rose up to 77.4% when using activated carbon (AC) particles with a median size of 27.03 μm. A maximum 96% of AC particles could be collected for reuse depending on the size and flow rate. The AC regenerated via thermal treatment showed an adsorption potential up to 66.7% throughout repeated tests.VOCs and particles have been of interest both in industrial field and public indoor spaces. In this study, a post cyclone (PoC) that utilizes a residual vortex from the mother cyclone was modified by inserting a flow guide and was applied to capture toluene vapor. The device of modified post-cyclone system can be used effectively in simultaneous treatment of gas-solid flow.
X-ray and γ-ray radiography have been indispensable techniques for materials inspection for many ... more X-ray and γ-ray radiography have been indispensable techniques for materials inspection for many years. Internal structure is typically inferred from radiographs by human evaluation. More precise information is possible if the function of three spatial variables can be estimated directly from the radiographic data. Several mathematical inversion formulae have been derived for deterministic reconstruction from the cone-beam integral projection data
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Papers by Huy Khanh