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Showing papers by "National Cheng Kung University published in 2000"


Journal ArticleDOI
TL;DR: Treatment with lamivudine for 2 years is both well tolerated and efficacious in patients with chronic hepatitis B and the emergence of YMDD mutant continued to clear serum HBeAg and maintain lower median serum HBV-DNA and ALT levels than baseline values.

703 citations


Journal ArticleDOI
TL;DR: To elucidate the clinical features, radiological classification, and prognostic factors of EPN; to compare the modalities of management and outcome among the various radiological classes; and to clarify the gas-forming mechanism and pathogenesis of EPM by gas analysis and pathological findings.
Abstract: Background Emphysematous pyelonephritis (EPN) is a rare, severe gas-forming infection of renal parenchyma and its surrounding areas. The radiological classification and adequate therapeutic regimen are controversial and the prognostic factors and pathogenesis remain uncertain. Objectives To elucidate the clinical features, radiological classification, and prognostic factors of EPN; to compare the modalities of management (ie, antibiotic treatment alone, percutaneous catheter drainage combined with antibiotic treatment, or nephrectomy) and outcome among the various radiological classes of EPN; and to clarify the gas-forming mechanism and pathogenesis of EPN by gas analysis and pathological findings. Patients and Methods Forty-eight EPN cases from our institution were enrolled between August 1,1989, and November 30, 1997. According to the radiological findings on computed tomographic scan, they were classified into the following classes: (1) class 1: gas in the collecting system only; (2) class 2: gas in the renal parenchyma without extension to extrarenal space; (3) class 3A: extension of gas or abscess to perinephric space; class 3B: extension of gas or abscess to pararenal space; and (4) class 4: bilateral EPN or solitary kidney with EPN. The clinical manifestations, management, and outcome were compared. The gas contents of specimens from 6 patients were analyzed. The pathological findings from 8 patients who received nephrectomy were reviewed. The statistical methods consisted of the Fisher exact test (2 tailed) for categorical variables and Wilcoxon rank sum test for continuous variables to test the predictors of poor prognosis. Results Forty-six patients (96%) had diabetes mellitus, and 10 (22%) of the 46 also had urinary tract obstruction in the corresponding renoureteral unit. The other 2 nondiabetic patients (4%) had severe hydronephrosis. Twenty-one (72%) of the 29 patients with diabetes mellitus also had a glycosylated hemoglobin A 1c level higher than 0.08. Escherichia coli (69%) and Klebsiella pneumoniae (29%) were the most common pathogens. The mortality rate in patients who received antibiotic treatment alone was 40% (2 of 5 patients). The success rate of management by percutaneous catheter drainage (PCD) combined with antibiotic treatment was 66% (27 of 41 patients). In classes 1 and 2 EPN, all the patients who were treated using a PCD or ureteral catheter combined with antibiotic treatment survived. In extensive EPN (classes 3 and 4), 17 (85%) of the 20 patients with fewer than 2 risk factors (ie, thrombocytopenia, acute renal function impairment, disturbance of consciousness, or shock) were successfully treated using PCD combined with antibiotic treatment; and the patients with 2 or more risk factors had a significantly higher failure rate than those with no or only 1 risk factors (92% vs 15%, P Conclusions Acute renal infection with E coli or K pneumoniae in patients with diabetes mellitus and/or urinary tract obstruction is the cornerstone for the development of EPN. Mixed acid fermentation of glucose by Enterobacteriaceae is the major pathway of gas formation. For localized EPN (classes 1 and 2), PCD combined with antibiotic treatment can provide a good outcome. For extensive EPN (classes 3 and 4) with a more benign manifestation (ie,

650 citations


Journal ArticleDOI
TL;DR: This paper addresses the adaptive synchronization problem of the drive–driven type chaotic systems via a scalar transmitted signal via the Lyapunov approach and verifies the proposed scheme’s success in the communication application.
Abstract: This paper addresses the adaptive synchronization problem of the drive–driven type chaotic systems via a scalar transmitted signal. Given certain structural conditions of chaotic systems, an adaptive observer-based driven system is constructed to synchronize the drive system whose dynamics are subjected to the system’s disturbances and/or some unknown parameters. By appropriately selecting the observer gains, the synchronization and stability of the overall systems can be guaranteed by the Lyapunov approach. Two well-known chaotic systems: Rossler-like and Chua’s circuit are considered as illustrative examples to demonstrate the effectiveness of the proposed scheme. Moreover, as an application, the proposed scheme is then applied to a secure communication system whose process consists of two phases: the adaptation phase in which the chaotic transmitter’s disturbances are estimated; and the communication phase in which the information signal is transmitted and then recovered on the basis of the estimated parameters. Simulation results verify the proposed scheme’s success in the communication application.

500 citations


Journal ArticleDOI
TL;DR: In this article, the synthesis of nickel nanoparticles by the reduction of nickel chloride with hydrazine in the cationic water-in-oil microemulsions of water/CTAB (cetyltrimethylammonium bromide)/n-hexanol at 73 °C has been studied.
Abstract: The synthesis of nickel nanoparticles by the reduction of nickel chloride with hydrazine in the cationic water-in-oil microemulsions of water/CTAB (cetyltrimethylammonium bromide)/n-hexanol at 73 °C has been studied. By the analyses of electron diffraction pattern and X-ray diffraction, the resultant particles were characterized to be the pure nickel crystalline with a face-centered cubic (fcc) structure. The investigation on the composition of microemulsion solution indicated that the average diameter of nickel nanoparticles was affected mainly by the ratio of CTAB to n-hexanol instead of the size of microemulsion droplets. Smaller particles could be obtained at higher ratios of CTAB to n-hexanol. At a constant nickel chloride concentration, the average diameter of nickel nanoparticles decreased with the increase of hydrazine concentration and then approached to a constant value when the concentration ratio of hydrazine to nickel chloride was above 10. At a sufficient high hydrazine concentration, the av...

471 citations


Journal ArticleDOI
TL;DR: A procedure to measure the efficiencies of DMUs with fuzzy observations by applying the α-cut approach, and by extending to fuzzy environment, the DEA approach is made more powerful for applications.

455 citations


Journal ArticleDOI
TL;DR: A prospective study of Klebsiella pneumoniae bacteremia revealed a close relationship between ESBL production and ciprofloxacin resistance, which is particularly worrisome because the first reported instance of plasmid-mediated ciprafloxACin resistance has been in an isolate of K. pneumoniae also possessing an ESBL.
Abstract: A prospective study of Klebsiella pneumoniae bacteremia was performed in 12 hospitals in 7 countries. Of 452 episodes of bacteremia, 25 (5.5%) were caused by K. pneumoniae that was resistant in vitro to ciprofloxacin. Extended-spectrum β-lactamase (ESBL) production was detected in 15 (60%) of 25 ciprofloxacin-resistant isolates, compared with 68 (16%) of 427 ciprofloxacin-susceptible strains ( ). Multivariate analysis revealed that risk factors for ciprofloxacin resistance in K. pneumoniae included prior receipt of a quinolone ( ) and an ESBL-producing strain ( ). In all, 18% of ESBL-producing isolates were also ciprofloxacin-resistant. Pulsed-field gel electrophoresis showed that 11 of the 15 ciprofloxacin-resistant ESBL-producing strains belonged to just 4 genotypes, suggesting that patient-to-patient transmission of such strains occurred. The close relationship between ESBL production and ciprofloxacin resistance is particularly worrisome because the first reported instance of plasmid-mediated ciprofloxacin resistance has been in an isolate of K. pneumoniae also possessing an ESBL.

410 citations


Journal ArticleDOI
TL;DR: This paper proposes an efficient and practical remote user authentication scheme using smart cards that provides the same advantages as that of Hwang and Li's scheme, but also significantly reduces the communication and computation costs.
Abstract: Based on the discrete logarithm problem, Hwang and Li (see ibid., vol.46, no.1, p.28-30, Feb. 2000) proposed a remote user authentication scheme using smart cards. Their scheme is very novel because no password table is required to keep in a system. In this paper, we further propose an efficient and practical remote user authentication scheme using smart cards. The proposed scheme not only provides the same advantages as that of Hwang and Li's scheme, but also significantly reduces the communication and computation costs.

397 citations


Journal ArticleDOI
01 Jan 2000-Carbon
TL;DR: In this paper, the influence of the mesopore volume and the size of adsorbates on the adsorption capacity of granular activated carbons and activated carbon fabric was explored.

318 citations


Journal ArticleDOI
TL;DR: The results suggest that VEGF may play a role in the progression of colon cancer, although evaluation of this angiogenic phenotype did not provide additional prognostic information compared with that obtained from Dukes' staging of the tumours.

301 citations


Journal ArticleDOI
TL;DR: A circular chain control (3C) strategy for inverters in parallel operation is presented in the paper to reach the robustness of the multimodule inverter system and to reduce possible interactive effects among inverters.
Abstract: A circular chain control (3C) strategy for inverters in parallel operation is presented in the paper. In the proposed inverter system, all the modules have the same circuit configuration, and each module includes an inner current loop and an outer voltage loop control. A proportional-integral controller is adopted as the inner current loop controller to expedite the dynamic response, while an H/sup /spl infin// robust controller is adopted to reach the robustness of the multimodule inverter system and to reduce possible interactive effects among inverters. With the 3C strategy, the modules are in circular chain connection and each module has an inner current loop control to track the inductor current of its previous module, achieving an equal current distribution. Simulation results of two-module and a three-module inverter systems with different kinds of loads and with modular discrepancy have demonstrated the feasibility of the proposed control scheme. Hardware measurements are also presented to verify the theoretical discussion.

272 citations


Journal ArticleDOI
TL;DR: In this article, a new resonator-embedded cross-coupled filter, constructed by stepped-impedance hairpin resonators and miniaturized hairpin resonance, is presented.
Abstract: Stepped-impedance resonators have been thoroughly studied in this paper. Two equations for odd- and even-mode resonance are derived from a new network model. The size and resonant frequencies of the resonator could then be designed based on these two equations. A new resonator-embedded cross-coupled filter, constructed by stepped-impedance hairpin resonators and miniaturized hairpin resonators is presented. This new filter is very compact and has lower spurious response. A 0/spl deg/ feed structure, which adds two transmission zeros to the filter response, is also studied. The two zeros are so close to the passband that the selectivity and out-of-band rejection of the filter are significantly increased. The design has been verified by experiment results.

Journal ArticleDOI
TL;DR: With increasing knowledge of anatomy and refinements of surgical technique, the anterolateral thigh flap can be harvested safely to reconstruct complicated defects of head and neck following cancer ablation with only minimal donor-site morbidity.
Abstract: Thirty-seven consecutive free anterolateral thigh flaps in 36 patients were transferred for reconstruction of head and neck defects following cancer ablation between January of 1997 and June of 1998. The success rate was 97 percent (36 of 37), with one flap lost due to a twisted perforator. The anatomic variations and length of the vascular pedicle were investigated to obtain better knowledge of anatomy and to avoid several surgical pitfalls when it is used for head and neck reconstruction. The cutaneous perforators were always found and presented as musculocutaneous or septocutaneous perforators in this series of 37 anterolateral thigh flaps. They were classified into four types according to the perforator derivation and the direction in which it traversed the vastus lateralis muscle. In type I, vertical musculocutaneous perforators from the descending branch of the lateral circumflex femoral artery were found in 56.8 percent of cases (21 of 37), and they were 4.83 +/- 2.04 cm in length. In type II, horizontal musculocutaneous perforators from the transverse branch of the lateral circumflex femoral artery were found in 27.0 percent of cases (10 of 37), and they were 6.77 +/- 3.48 cm in length. In type III, vertical septocutaneous perforators from the descending branch of the lateral circumflex femoral artery were found in 10.8 percent of cases (4 of 37), and they were 3.60 +/- 1.47 cm in length. In type IV, horizontal septocutaneous perforators from the transverse branch of the lateral circumflex femoral artery were found in 5.4 percent of cases (2 of 37). They were 7.75 +/- 1.06 cm in length. The average length of vascular pedicle was 12.01 +/- 1.50 cm, and the arterial diameter was around 2.0 to 2.5 mm; two accompanying veins varied from 1.8 to 3.0 mm and were suitable for anastomosis with the neck vessels. Reconstruction of one-layer defect, external skin or intraoral lining, was carried out in 18 cases, through-and-through defect in 17 cases, and composite mandibular defect in two cases. With increasing knowledge of anatomy and refinements of surgical technique, the anterolateral thigh flap can be harvested safely to reconstruct complicated defects of head and neck following cancer ablation with only minimal donor-site morbidity.

Journal ArticleDOI
TL;DR: In this paper, the tribological behavior of self-lubricated aluminium/SiC/graphite hybrid composites with various amount of graphite addition synthesized by the semi-solid powder densification (SSPD) method has been studied.

Journal ArticleDOI
TL;DR: An effective fuzzy multicriteria analysis approach to performance evaluation for urban public transport systems involving multiple criteria of multilevel hierarchies and subjective assessments of decision alternatives is presented.

Journal ArticleDOI
TL;DR: A sufficient condition related to the existence of a unique equilibrium point and its global asymptotic stability for cellular network networks with delay (DCNNs) is derived and it is shown that the condition relies on the feedback matrices and is independent of the delay parameter.
Abstract: A sufficient condition related to the existence of a unique equilibrium point and its global asymptotic stability for cellular network networks with delay (DCNNs) is derived. It is shown that the condition relies on the feedback matrices and is independent of the delay parameter. Furthermore, this condition is less restrictive than that given in the literature.

Journal ArticleDOI
TL;DR: Sperm of exposed children have increased abnormal morphology, reduced motility, and reduced capacity to penetrate hamster oocytes, and how these effects can be extrapolated to the general population exposed to background levels of PCBs and dioxin-like chemicals, warrants further investigation.

Journal ArticleDOI
TL;DR: This study shows that oral stevioside is a well tolerated and effective modality that may be considered as an alternative or supplementary therapy for patients with hypertension.
Abstract: Aims Stevioside is a natural plant glycoside isolated from the plant Stevia rebaudiana which has been commercialized as a sweetener in Japan for more than 20 years. Previous animal studies have shown that stevioside has an antihypertensive effect. This study was to designed to evaluate the effect of stevioside in human hypertension. Methods A multicentre, randomized, double-blind, placebo-controlled study was undertaken. This study group consisted of 106 Chinese hypertensive subjects with diastolic blood pressure between 95 and 110 mmHg and ages ranging from 28 to 75 years with 60 subjects (men 34, women 26; mean t s.d., 54.1t3.8 years) allocated to active treatment and 46 (men 19, women 27; mean t s.d., 53.7t4.1 years) to placebo treatment. Each subject was given capsules containing stevioside (250 mg) or placebo thrice daily and followed-up at monthly intervals for 1 year. Results After 3 months, the systolic and diastolic blood pressure of the stevioside group decreased significantly (systolic: 166.0t9.4‐152.6t6.8 mmHg; diastolic: 104.7t5.2‐90.3t3.6 mmHg, P<0.05), and the effect persisted during the whole year. Blood biochemistry parameters including lipid and glucose showed no significant changes. No significant adverse effect was observed and quality of life assessment showed no deterioration. Conclusions This study shows that oral stevioside is a well tolerated and effective modality that may be considered as an alternative or supplementary therapy for patients with hypertension.

Journal ArticleDOI
TL;DR: In this paper, a multiobjective programming model for the optimal allocation of passenger train services on an intercity high-speed rail line without branches is developed to minimize the operator's total operating cost and minimize the passenger's total travel time loss.
Abstract: This paper develops a multiobjective programming model for the optimal allocation of passenger train services on an intercity high-speed rail line without branches. Minimizing the operator's total operating cost and minimizing the passenger's total travel time loss are the two planning objectives of the model. For a given many-to-many travel demand and a specified operating capacity, the model is solved by a fuzzy mathematical programming approach to determine the best-compromise train service plan, including the train stop-schedule plan, service frequency, and fleet size. An empirical study on the to-be-built high-speed rail system in Taiwan is conducted to demonstrate the effectiveness of the model. The case study shows that an optimal set of stop-schedules can always be generated for a given travel demand. To achieve the best planning outcome, the number and type of stop-schedules should be flexibly planned, and not constrained by specific stopping schemes as often set by the planner.

Journal ArticleDOI
TL;DR: This paper shows a new off-line guessing attack on Steiner, Tsudik and Waidners' protocol and proposes a new three-party EKE protocol which not only is secure against both the off-lines guessing attack and undetectable on-line guesses but also satisfies the security properties of perfect forward secrecy and known-key security.
Abstract: Password-based mechanism is the widely used method for authentication since it allows people to choose their own passwords without any assistant device to generate or store. However, people are used to choose easy-to-remember passwords such that guessing attacks could succeed. In 1992, Bellovin and Merritt proposed Encrypted Key Exchange (EKE) protocols for preventing guessing attacks, in which two communication parties A and B securely share a possibly weak password in advance. In large communication environments, it is inconvenient in key management that every two communication parties mutually share a secret. Three-party EKE protocols, in which all parties (clients) share their secrets with a trusted server only, are more suitable for large communication environments. In 1995, Steiner, Tsudik and Waidner proposed a realization of three-party EKE protocol which is later demonstrated that it is vulnerable to undetectable on-line guessing attacks. In this paper, We will show a new off-line guessing attack on Steiner, Tsudik and Waidners' protocol. Besides, we will also propose a new three-party EKE protocol which not only is secure against both the off-line guessing attack and undetectable on-line guessing attacks but also satisfies the security properties of perfect forward secrecy and known-key security.

Journal ArticleDOI
TL;DR: In this paper, a constitutive equation is used successfully to describe the dynamic impact deformation behavior of 7075 Al alloy, considering the effects of strain rate, temperature, strain hardening, rate sensitivity and thermal softening of the material.

Journal ArticleDOI
TL;DR: The experience demonstrated that the EV71 isolated in Taiwan had strong dermatotropic as well as neurotropic tendencies, and early detecting CNS involvement and commencing aggressive therapy may reduce the mortality.

Journal ArticleDOI
TL;DR: Increase of glucose utilization by caffeic acid seems to be responsible for the lowering of plasma glucose in diabetic rats of both streptozotocin-induced and insulin-resistant models.
Abstract: The antihyperglycemic effect of caffeic acid, one of the phenolic compounds contained in the fruit of Xanthium strumarium, was investigated. After an intravenous injection of caffeic acid into diabetic rats of both streptozotocin-induced and insulin-resistant models, a dose-dependent decrease of plasma glucose was observed. However, a similar effect was not produced in normal rats. An insulin-independent action of caffeic acid can thus be considered. Otherwise, this compound reduced the elevation of plasma glucose level in insulin-resistant rats receiving a glucose challenge test. Also, glucose uptake into the isolated adipocytes was raised by caffeic acid in a concentration-dependent manner. Increase of glucose utilization by caffeic acid seems to be responsible for the lowering of plasma glucose.

Journal ArticleDOI
TL;DR: In this article, a thermogravimetric study showed that ZnCl2, H3PO4 and KOH were capable of suppressing the evolution of tarry substances during carbonization.

Journal ArticleDOI
TL;DR: In this article, the photoreactivities of methoxy and ethoxy groups on TiO2 have been studied by Fourier transformed infrared spectroscopy and a Russell-like mechanism was invoked to explain the formation of the reaction products.
Abstract: Thermo- and photoreactivities of methoxy (CH3O(a)) and ethoxy groups (C2H5O(a)) bonded, via the oxygen atom, to one Ti ion (monodentate adsorption form) or to two Ti ions (bidentate adsorption form) on TiO2 have been studied by Fourier transformed infrared spectroscopy. Regardless of the similar thermal stability for the two adsorption geometries of the adsorbed alkoxy groups, difference in photoreactivity is observed by monitoring the change of their integrated IR absorptions as a function of UV irradiation time. The monodentate photooxidation rate is ∼1.5 times that of bidentate for both methoxy and ethoxy groups. CH3O(a) on TiO2 is photooxidized to H2O(a) and HCOO(a) in the presence of O2. On the other hand, C2H5O(a) is photooxidized to H2O(a), HCOO(a), and CH3COO(a). A Russell-like mechanism is invoked to explain the formation of the reaction products. Possible reaction steps that control the photoreactivity of the monodentate and bidentate adsorption forms are discussed in terms of this mechanism.

Journal ArticleDOI
TL;DR: The notions of the “whole” and the use of “relative” rather than absolute are important concepts, which distinguish CTM from modern medicine.
Abstract: This article addresses the differences between the basic concepts of drug therapy in Chinese traditional medicine (CTM) and modern Western medicine. In ancient times, throughout the world, humans used plants as food and medicine. In Europe, chemistry developed rapidly after the influence of Paracelsus. Active principles were isolated from plants, and drugs were prepared in the salt form to use as medication. In China, several drugs isolated from plants have been prepared in the salt form in recent years, but herbal medication, developed in the ancient tradition, continued to be widely used in Chinese populations. Some theories such as the yin-yang theory and the five-element theory were commonly employed to explain the rationale for the use of CTM. In this review, hypertension and diabetes mellitus are used as examples to illustrate the applications of CTM. The notions of the “whole” and the use of “relative” rather than absolute are important concepts, which distinguish CTM from modern medicine.

Journal ArticleDOI
01 Jan 2000-Carbon
TL;DR: In this article, a mixture of KOH impregnation and carbonization in nitrogen at 500-900°C for 0-3 h, followed by CO2 gasification to different degrees of burn-off.

Journal ArticleDOI
TL;DR: The proposed adaptive grid size procedure provides concise adjustment policy and raises computational efficiency of using differential transformation method to approximate solutions of linear and nonlinear initial-value problems.

Journal ArticleDOI
TL;DR: This study used a NaClO2/NaOH solution as the additive/absorbent to determine the extent of NOx removal in a wet scrubbing system and found that the maximum DeNOx and DeSOx efficiencies ranged from 36.6 to 71.9% and from 89.4 to 100.0%, respectively.

Journal ArticleDOI
TL;DR: In this paper, an immune algorithm (IA) based optimization approach for solving the capacitor placement problem is proposed, in which the objective functions and constraints are represented as antigens through the genetic evolution, an antibody that most fits the antigen becomes the solution.
Abstract: An immune algorithm (IA) based optimization approach for solving the capacitor placement problem is proposed in this paper. In the capacitor placement problem, those practical capacitor operating constraints, load profiles, feeder capacities and allowable voltage limits at different load levels are all considered while the investment cost and energy loss are minimized. In the proposed method, objective functions and constraints are represented as antigens. Through the genetic evolution, an antibody that most fits the antigen becomes the solution. In this IA computation, an affinity calculation process is also embedded to guarantee the diversity. The process stagnation can be thus better prevented. The proposed method has been applied to a test system and the results are compared with other published techniques.

Journal ArticleDOI
TL;DR: The results suggest that endothelial cells can be a target for DV infection, and that DV-induced IL-6 and IL-8 production by endothelial Cells may contribute to the pathogenesis of dengue hemorrhagic fever.
Abstract: In this study dengue virus (DV) was found to infect primary endothelial cells derived from human umbilical cord veins (HUVEC) and alter their cytokine production. Dengue virus infection of HUVEC was confirmed by an increase in plaque-forming units in the culture supernatant and by immunofluorescence assay. HUVEC produced large amounts of interleukin (IL)-6 and IL-8 but not IL-1beta after DV infection. Both the replication of DV and the production of IL-6 and IL-8 by HUVEC after DV infection were inhibited by ribavirin, an antiviral synthetic guanosine analogue. Additionally, increased serum levels of IL-6 and IL-8 were observed in patients with dengue hemorrhagic fever but not dengue fever. Therefore, our results suggest that endothelial cells can be a target for DV infection, and that DV-induced IL-6 and IL-8 production by endothelial cells may contribute to the pathogenesis of dengue hemorrhagic fever.