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Showing papers by "National Cheng Kung University published in 1994"


Journal Article
TL;DR: Data indicate that both Gram-negative and Gram-positive bacteria could induce thymus atrophy via apoptosis, and that TNF-alpha is a common denominator released and might be responsible for the thymocyte apoptosis.
Abstract: Intraperitoneal injection of Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) induces thymic atrophy in mice The thymus weight, cell number, and viability began to decrease at 3 h, and reached their lowest level at 72 h The thymocyte death was associated with DNA fragmentation of approximately 200 base pairs in ladder form The kinetic study on histopathology revealed the process of thymocyte death and thymic atrophy Flow-cytometric analysis showed that CD4+CD8+ thymocytes decreased predominantly LPS caused thymocyte apoptosis, but only in LPS-responder mice, unlike Gram-negative bacteria that induced apoptosis in both LPS-responder (C3H/HeN) and LPS-nonresponder (C3H/HeJ) Gram-positive bacteria Streptococcus pneumoniae also caused apoptosis in LPS-nonresponder (C3H/HeJ) and LPS-responder mice (B6) The kinetics of serum TNF-alpha production after Gram-negative or Gram-positive bacteria injection was slightly different E coli induced serum TNF-alpha peak at 1 h in B6 mice, whereas S pneumoniae induced a peak at 6 h in C3H/HeJ and at 9 h in B6 mice Similarly, S pneumoniae induced thymocyte apoptosis around 9 to 12 h, which was 6 to 9 h later than that observed with E coli in B6 mice Anti-TNF-alpha Ab completely blocked the E coli-induced thymocyte apoptosis, but was only partially inhibitory on the S pneumoniae-induced thymocyte apoptosis Furthermore, thymocyte apoptosis induced by E coli was inhibited by cycloheximide or actinomycin D These data indicate that both Gram-negative and Gram-positive bacteria could induce thymus atrophy via apoptosis, and that TNF-alpha is a common denominator released and might be responsible for the thymocyte apoptosis

223 citations


Journal ArticleDOI
TL;DR: High academic achievement as assessed by a test of mathematics was generally not associated with psychological maladjustment and the only exception was in the United States, where high achievers indicated more frequent feelings of stress than did low achievers.
Abstract: Psychological maladjustment and its relation to academic achievement, parental expectations, and parental satisfaction were studied in a cross-national sample of 1,386 American, 1,633 Chinese, and 1,247 Japanese eleventh-grade students. 5 indices of maladjustment included measures of stress, depressed mood, academic anxiety, aggression, and somatic complaints. Asian students reported higher levels of parental expectation and lower levels of parental satisfaction concerning academic achievement than their American peers. Nevertheless, Japanese students reported less stress, depressed mood, aggression, academic anxiety, and fewer somatic complaints than did American students. Chinese students reported less stress, academic anxiety, and aggressive feelings than their American counterparts, but did report higher frequencies of depressed mood and somatic complaints. High academic achievement as assessed by a test of mathematics was generally not associated with psychological maladjustment. The only exception was in the United States, where high achievers indicated more frequent feelings of stress than did low achievers.

223 citations


Journal ArticleDOI
TL;DR: It is concluded that platelet adhesiveness and aggregability may be sensitized by strenuous exercise in both healthy subjects and patients with stable angina.
Abstract: BACKGROUNDPlatelets play an important role in the pathogenesis of cardiovascular diseases. It is also noticed that on one hand, regular exercise can reduce the risk of cardiovascular diseases, and on the other hand, vigorous exercise provokes sudden cardiac death. We therefore hypothesize that various intensities of exercise may affect platelet function differently.METHODS AND RESULTSStrenuous and moderate exercise (about 50% to 55% of peak oxygen consumption, VO2peak) on a bicycle ergometer in 10 sedentary and 10 physically active healthy young men was executed on two separate occasions. Blood samples were collected before and immediately after exercise. A newly designed tapered parallel plate chamber was used to assess platelet adhesiveness. Platelet aggregation induced by ADP was evaluated by the percentage of reduction in single platelet count. beta-Thromboglobulin (beta-TG) and platelet factor 4 (PF4) were measured by ELISA. In addition, a similar study on 5 patients with stable angina were also cond...

213 citations


Journal ArticleDOI
01 Feb 1994
TL;DR: In this paper, physical constraints are considered in the general formulation of the redundant inverse kinematic problem and the computationally efficient compact quadratic programming (QP) method is formed to resolve the constrained kinematics redundancy problem.
Abstract: Due to hardware limitations, physical constraints such as joint rate bounds, joint angle limits, and joint torque constraints always exist. In this paper, these constraints are considered in the general formulation of the redundant inverse kinematic problem. To take these physical constraints into account, the computationally efficient compact quadratic programming (QP) method is formed to resolve the constrained kinematic redundancy problem. In addition, the compact-inverse QP method is also formulated to remedy the inescapable singularity problem with inequality constraints. Two examples are given to demonstrate the generality and superiority of these two methods: to eliminate the drift phenomenon caused by self motion and to remedy saturation-type nonlinearity problems. >

159 citations


Journal ArticleDOI
TL;DR: In utero exposure to heat-degraded PCBs appears to cause mildly disordered behavior and increased activity level; the effect persists over time and is similar in children born up to 6 years after the mothers were exposed.
Abstract: OBJECTIVES. The relationship of behavior and activity levels to the interval between outbreak and year of birth and to age of children is explored in Taiwanese children exposed in utero to heat-degraded polychlorinated biphenyls (PCBs)--the Yu-cheng children. Additionally, the relationship of the scores to chemical, physical, and cognitive findings is described. METHODS. With Rutter's Child Behavior Scale A and a modified Werry-Weiss-Peters Activity Scale, 118 Yu-chen children and matched controls were followed biannually from 1985 to 1991. RESULTS. At each year, the Yu-cheng children scored 7% to 43% worse (mean = 23%) than control children on the Rutter scale. At any fixed age, the Yu-cheng children scored 11% to 63% (mean = 28%) worse. The effect for children born later did not differ from that for those born earlier; neither was there any improvement as the children aged. A similar but weaker picture was seen for the activity score. These behavioral findings were not related to physical or cognitive f...

132 citations


Journal ArticleDOI
TL;DR: In this article, a realistic 3D man model and an approximate linear dipole antenna were used to model the EM coupling effects of a human operator on antenna radiation characteristics, such as the antenna input impedance, radiation patterns, the radiation power (into free space), the power absorbed by the body, and the radiation efficiency, etc.
Abstract: EM coupling effects of a human operator on antenna radiation characteristics, such as the antenna input impedance, radiation patterns, the radiation power (into free space), the power absorbed by the body, the radiation efficiency, etc., of a portable communication dipole antenna were investigated in detail. A realistically shaped 3D man model and an approximate linear dipole antenna were used to model this problem. Coupled integral equations (CIE) and the method of moments (MoM) were employed to numerically solve this antenna-body coupling problem. Numerical examples are presented for the antenna located in front of the head (distance ranging from 5 to 1 cm) or adjacent to the abdomen (0.6 cm distance) at 830 MHz. It is found that, when coupled with the operator body, the antenna input impedance will have significant deviation from those in free space and different positions. Due to the operator body absorption effect, the maximum attenuation of the H-plane antenna gain may reach about 15 dB for the antenna at the head position and 25 dB for the abdomen position, toward the direction of the body side. Also, the antenna radiation efficiency is reduced to the range from 0.72 to 0.29 for the head position and 0.15 for the abdomen position, respectively. Moreover, the cross-polarization field is significant, especially in the E plane of /spl phi/=90/spl deg/. This is important for the antenna RF design and communication link budget consideration of portable radio systems. >

126 citations


Journal ArticleDOI
TL;DR: In this article, the authors used the conjugate gradient method in a two-dimensional inverse problem to estimate the unknown temporal and spatial variation of inside heat fluxes of a heat generated enclosure.
Abstract: The methodology in estimating the unknown temporal and spatial variation of inside heat fluxes of a heat‐generated enclosure is derived by using the conjugate gradient method in a two‐dimensional inverse problem. The advantage of the conjugate gradient method is that there is no need to assume a specific functional form for the unknown quantities beforehand, since the solution automatically determines the functional form over the domains specified. Such a technique can be applied to determine the internal wall heat fluxes acting on the inner and upper surfaces in the cylinder of an internal combustion engine, simultaneously, from the knowledge of transient temperature measurements taken inside the cylinder block and head, respectively, which is discussed in detail. The other application is the determination of inside heat fluxes of a nuclear fuel rod. Once wall heat fluxes inside the cylinder are determined, the exhaust heat produced by the cylinder head and block can be calculated. Furthermore, the cooli...

124 citations


Book ChapterDOI
09 May 1994
TL;DR: This paper proposes a new type of signature scheme, called the (t, n) threshold-multisignature scheme, where at least t shareholders of a specific group have to cooperate to generate a valid group signature and suspected forgery implies traceability of adversarial shareholders.
Abstract: In this paper, we are going to combine the idea of the (t, n) threshold signature scheme with the multisignature scheme and propose a new type of signature scheme, called the (t, n) threshold-multisignature scheme. In the (t, n) threshold-multisignature scheme, at least t shareholders of a specific group have to cooperate to generate a valid group signature and suspected forgery implies traceability of adversarial shareholders. The validity of that signature for the specific group can be verified without knowing the membership of the signers to that group.

122 citations


Journal ArticleDOI
TL;DR: The test results, although preliminary, suggest the new neural network diagnostic system for online power system fault section estimation using information of relays and circuit breakers can be implemented by various electric utilities with relatively low customization effort.
Abstract: This paper proposes a new neural network diagnostic system for online power system fault section estimation using information of relays and circuit breakers. This system has a similar profile of an expert system, but can be constructed much more easily from elemental samples. These samples associate fault section with its primary, local and/or remote protective relays and breakers. The diagnostic system can be applicable to the power system control center for single or multiple fault sections estimation, even in the cases of failure operation of relays and breakers, or error-existent data transmission. The proposed approach has been practically verified by testing on a model power system. The test results, although preliminary, suggest this system can be implemented by various electric utilities with relatively low customization effort. >

110 citations


Journal ArticleDOI
TL;DR: The addition of low-dose aspirin to a standard HRT protocol in women with impaired uterine perfusion is associated with improved blood flow and satisfactory pregnancy rates.
Abstract: The objective of this long-running study was to determine whether the addition of low-dose aspirin to a standard hormone replacement therapy (HRT) protocol improved uterine perfusion during assisted conception. A total of 99 women scheduled for frozen embryo replacement were studied. Endometrial preparation was with a standard buserelin/HRT protocol. Uterine perfusion was assessed by Doppler ultrasound and classified as impaired or normal. In their first attempts, those with impaired perfusion (group I, n = 37) received low doses of aspirin [150 mg (n = 26) or 300 mg daily (n = 11)], starting from day 13 of HRT. Women with normal perfusion (group II) did not receive aspirin. In subsequent attempts, those from group I were arbitrarily allocated to start aspirin on day 1 or day 13 of HRT, and 10 women from group II were arbitrarily selected to receive aspirin from day 1 of HRT. In group I, the cancellation (46 versus 36%) and pregnancy rates (15 versus 25%) in those who received 150 or 300 mg aspirin daily were similar. In those with cancelled first attempts, good perfusion was achieved in 82 versus 20% (P < 0.02) of subsequent attempts using aspirin from day 1 versus day 13 of HRT. Higher pregnancy rates (47 versus 17%) were achieved in those taking aspirin from day 1 of HRT. In group II, pregnancy rates were not statistically different in those who did or did not receive aspirin during their subsequent attempts (10 versus 35%). The addition of low-dose aspirin to a standard HRT protocol in women with impaired uterine perfusion is associated with improved blood flow and satisfactory pregnancy rates.

106 citations


Journal ArticleDOI
TL;DR: In this paper, the results of a series of plane strain model loading tests of footing on both reinforced and unreinforced sand slope made of a fine quartz-rich sand, Toyoura sand, performed under well-controlled loading conditions are described.

Journal ArticleDOI
TL;DR: A parallel method using a Competitive Hopfield Neural Network (CHNN) is proposed for polygonal approximation and is compared to several existing methods by the approximation error norms L2 and L∞ with the result that promising approximation polygons are obtained.

Journal ArticleDOI
TL;DR: In this paper, the effect of phosphorus on the corrosion behavior of electroless nickel-plated mild steel in neutral and alkaline 3.5 wt.% NaCl solutions was examined using d.c. polarization curves and a.
Abstract: Electroless Ni-P deposits with phosphorus contents ranging from 4.8 to 12.8 wt.% were examined using d.c. polarization curves and a.c. electrochemical impedance spectroscopy techniques to characterize the effect of phosphorus on the corrosion behavior of electroless nickel-plated mild steel in neutral and alkaline 3.5 wt.% NaCl solutions. The anodic polarization behavior of the Ni-P alloys in NaCl electrolyte was very similar for all deposits except Ni-4.8P. According to the electrochemical impedance data, the charge transfer resistance R ct and film resistance R f of these deposits have subsequently been studied as functions of the phosphorus content. It was shown that the R ct and R f values increased with increasing phosphorus content of the electroless nickel coating. The Ni-P deposits remained bright in appearance during the periods of electrochemical experiment, and no evidence of pitting was observed after testing. Based on X-ray photoelectron spectroscopy analysis, the passivation of Ni-P alloys was attributed to the formation and adsorption of a layer of hypophosphite.

Journal ArticleDOI
TL;DR: In this paper, the interdiffusion between an electroless NiP deposit and liquid solder was investigated with the aid of an X-ray diffractometer and a scanning electron microscope to identify the intermetallic compounds formed.

Journal ArticleDOI
01 Aug 1994-Stroke
TL;DR: It is suggested that bFGF produced by neurons, macrophages, and glial cells may participate in angiogenesis in brain infarct through the expression of basic fibroblast growth factor (bFGF).
Abstract: Cerebral endothelial cells are quiescent under normal conditions; they are stimulated to proliferate around an infarct, although the mechanism is unclear. In the present study we explored the relation between angiogenesis and the expression of basic fibroblast growth factor (bFGF) by participating cells in brain infarct.Brain infarct was created in rats by ligation of a branch of the left middle cerebral artery followed by permanent occlusion of the left common carotid artery and temporary occlusion of the right common carotid artery. The brains were removed after 1 to 14 days and studied with histological and immunohistochemical methods. Bromodeoxyuridine (BRdU) was used as an S-phase marker for the proliferative cells.Enhanced bFGF immunoreactivity was observed in neurons adjacent to the infarct after 1 day, and the change subsequently spread to distant neurons in the ipsilateral hemisphere. After 2 days blood vessels and glial cells around the infarct began to incorporate BRdU. During the first week ne...

Journal ArticleDOI
TL;DR: The results suggest that VPA's anticonvulsant effect is due, at least in part, to its blocking action on the EPSPNMDA, and that higher concentration of VPA suppressed the normal synaptic transmission.

Journal ArticleDOI
TL;DR: In this article, cyclic voltammetry on IrO2-coated titanium electrodes in 0.5m H2SO4 was used for copolymerization of aniline (AN) and para-phenylenediamine (PPDA).
Abstract: Copolymerization of aniline (AN) and para-phenylenediamine (PPDA) was electrochemically performed by cyclic voltammetry on IrO2-coated titanium electrodes in 0.5m H2SO4. The cyclic voltammograms, with and without a middle peak at about 580 mV, can be produced by controlling the PPDA concentration in the aniline solution during polymer preparation. The peak at about 580 mV corresponds to the para-aminophenol/benzoquinoneimine (PAP/QI) redox couple and crosslinking sites. The mass of polymer deposited on an IrO2-coated titanium electrode is correlated with the polymer anodic peak current, which allows the rates of polymer deposition to be monitored by increases in the anodic peak current at various PPDA concentrations. SEM photographs show that the morphology of the polymer film depends dramatically on PPDA concentration. Stability test information can be used in generating an effective index to discern between the crosslinking and the PAP/QI reactions induced by PPDA. The linear relationship between the second redox process potential (E 1/2), corresponding to the oxidation and reduction between polaronic emeraldine and pernigraniline in PPDA-modified PANI films, and pH, possesses a slope of about -120 mV/pH.

Journal ArticleDOI
TL;DR: In this paper, a nonisothermal 3-D computer simulation model for the mold filling process of RTM based on the control volume finite element method was developed, which is able to simulate mold filing in molds with complicated 3D geometry.
Abstract: The manufacture of polymer composites through the process of resin transfer molding (RTM) involves the impregnation of the reactive polymer resing into a mold with preplaced fibrous reinforcements. Determination of RTM processing conditions requires the understanding of various parameters, such as material properties, mold geometry, and mold filling conditions. Modeling of the entire RTM process provides a tool for analyzing the relationship of the important parameters. This study developed a nonisothermal 3-D computer simulation model for the mold filling process of RTM based on the control volume finite element method. The model will be able to simulate mold filing in molds with complicated 3-D geometry. Results of some numerical studies in RTM show the applications of the proposed model.

Journal ArticleDOI
TL;DR: In this paper, a gate location optimization method was developed based on minimization of the mold filling pressure, uneven filling pattern, and temperature difference during mold filling process, and a genetic algorithm was used to search the optimal gate location.
Abstract: Manufacture of polymer composites using the process of liquid composite molding involves injection of a reactive resin into a closed mold with preplaced fibrous reinforcements. There are many studies that address the computer simulations for mold filling. The simulation programs provide the simulated mold filling results for a known gate location. However, they do not discuss the method for determination of the gate locations, which is one of the important issues in the total mold design. In this paper, a gate location optimization method was developed based on minimization of the mold filling pressure, uneven filling pattern, and temperature difference during the mold filling process. A genetic algorithm was used to search the optimal gate location. This method, in general, has a better chance to locate the near global optimum than the gradient based search method, especially in the problems with multiple variables and a large search space.

Journal ArticleDOI
TL;DR: In this article, a local high order deformation theory is used to determine the natural frequencies and buckling loads of laminated composite plates, where the displacement fields in this theory are assumed to be piece-wise continuous high order polynomial series.

Journal ArticleDOI
TL;DR: The data indicate that interleukin-1 production plays a role in pathogenesis of heat stroke in rabbits and that the heat-stroke animals which received an i.v. injection of interLEukin 1-receptor antagonist had a survival time longer than those which received control-vehicle solution.

Journal ArticleDOI
TL;DR: In this paper, the effect of aspect ratio on convection heat transfer inside a vertical rectangular enclosure with four two-dimensional discrete flush-mounted heaters is investigated numerically and experimentally.

Journal ArticleDOI
01 Dec 1994-Stroke
TL;DR: It is suggested that an increase in hypothalamic dopamine release and a decrease in local cerebral blood flow occur during onset of heatstroke, and pretreatment with IL-lra attenuates the heatstroke formation resulting from cerebral ischemia by reducing hypothalamic serotonin release.
Abstract: Brain dopamine has been implicated as a mediator of brain neuronal damage resulting from ischemic injury. Augmented interleukin-1 production and cerebral ischemia occurred during onset of heatstroke. This study has attempted to ascertain whether heatstroke resulting from hyperthermia causes an increase in hypothalamic dopamine release and to assess whether the administration of an interleukin-1 receptor antagonist (IL-1ra) can attenuate heat-stroke formation. Both local cerebral blood flow and hypothalamic dopamine release during onset of heatstroke were assessed in saline-treated rats and in rats treated with an IL-1ra. Heat-stroke was induced by exposing the animals to a high ambient temperature. Hypothalamic dopamine release was determined by carbon fiber electrodes combined with in vivo differential pulse amperometry. During onset of heatstroke, rats with heatstroke displayed higher values of colonic temperature, higher values of hypothalamic dopamine release, and lower values of blood flow in different brain regions compared with normothermic control rats. In another separate experiment in which IL-1ra (200 micrograms/kg IV) was injected 30 minutes before onset of heatstroke, both the augmented hypothalamic dopamine release and diminished cerebral blood flow during onset of heatstroke were significantly attenuated. In addition, the survival time (interval between onset of heatstroke and death) of the rats with heatstroke was prolonged by pretreatment with IL-1ra. These results suggest that an increase in hypothalamic dopamine release and a decrease in local cerebral blood flow occur during onset of heatstroke. Pretreatment with IL-1ra attenuates the heatstroke formation resulting from cerebral ischemia by reducing hypothalamic dopamine release.

Journal ArticleDOI
TL;DR: In this paper, the ballistic limit of plain woven glass/epoxy composite laminates struck by a 14.9 gm bullet-like rigid projectile with a tip radius of 5 mm was predicted.

Journal ArticleDOI
01 Jun 1994-Gut
TL;DR: It is concluded that hypovolaemic shock, a non-bleeding visible vessel, and an adherent clot on an ulcer base are of independent significance in predicting rebleeding.
Abstract: From September 1991 to December 1992, a prospective study was conducted to determine the risk factors and residual risk of rebleeding, and the evolutionary endoscopic changes in peptic ulcers that rebled. Emergency endoscopies were performed on 452 patients with haematemesis or a melaena, or both within 24 hours of admission. If the lesions were actively bleeding, then the patients were treated with injection sclerotherapy. A multivariate analysis of clinical, laboratory, and endoscopic variables of 204 patients with ulcer bleeding showed that hypovolaemic shock, a non-bleeding visible vessel, and an adherent clot on the ulcer base were independently significant in predicting rebleeding (p < 0.05). Considering these three factors according to the estimates of their regression coefficients showed that a non-bleeding visible vessel was the strongest predictor of rebleeding. The study of the residual risk of rebleeding after admission showed that most rebleeding episodes (94.1%), including all associated with hypovolaemic shock, surgical treatment, and death, occurred within 96 hours of admission. After this time, the residual risk of rebleeding was less than 1%. Study of the changes in endoscopic findings before and after rebleeding illustrated that all ulcers with a visible vessel or adherent clot showed at follow up endoscopy were derived from ulcers with initial major stigmata. It is concluded that hypovolaemic shock, a non-bleeding visible vessel, and an adherent clot on an ulcer base are of independent significance in predicting rebleeding. Observation for 96 hours is sufficient to detect most rebleeding episodes after an initial bleed from peptic ulcer.

Journal ArticleDOI
TL;DR: In this article, a simple and direct method has been proposed, which may be used for quantitatively distinguishing the mechanisms of domain reorientation processes in polycrystalline materials.
Abstract: A simple and direct method has been proposed, which may be used for quantitatively distinguishing the mechanisms of domain reorientation processes in polycrystalline materials. Using this method, the 90‡ domain reorientation in the Pb(Zr x Ti1−x )O3 ceramic under an electric field was examined through the X-ray diffraction analysis. It was found that polarization switching in the PZT ceramic with a composition near the morphotropic phase boundary, is predominantly controlled by the two successive 90‡ domain processes rather than only the 180‡ domain reversal process. Experimental results also indicate that the coercive field of ferroelectric ceramics is related to the cooperative deformation associated with each grain. This cooperative deformation arises from the 90‡ domain-reversal process.

Journal ArticleDOI
TL;DR: The shorter height and decreased total lean mass and soft tissue content were only seen in the Yu-Cheng children who were the first born after the ingestion, but not in subsequent children, likely due to decreased body burdens of the PCBs and related contaminants over time in the mothers.
Abstract: Fifty-five Yu-Cheng (oil-disease) children born between 1978 and 1985 to mothers who ate PCB-contaminated rice oil in 1978-1979 were studied and compared to age- and sex-matched control subjects in 1991. The children's growth profiles, bone mineral density and soft tissue composition, joint laxity, and serum parathyroid hormone, vitamin D, calcium, alkaline phosphatase, and phosphate were compared. The Yu-Cheng children were 3.1 cm (p < .05) smaller and had less total lean mass and soft tissue mass as compared to the matched control subjects. All other parameters studied were similar in both groups. The shorter height and decreased total lean mass and soft tissue content were only seen in the Yu-Cheng children who were the first born after the ingestion, but not in subsequent children. This was most likely due to decreased body burdens of the PCBs and related contaminants over time in the mothers.

Journal ArticleDOI
TL;DR: The experimental results showed that no ammonium ion was found in the feed solution under either phosphate or citrate buffer systems at 0.05-0.2 mol dm-3 and pH 6-9, which indicates that the water film between two membranes allows the carbamate ions to decompose into ammonium and carbonate ions completely before entering the anion-exchange membrane.
Abstract: A membrane reactor-separator, in which an anion-exchange membrane and a urease-immobilized poly(vinyl alcohol) (PVA) membrane were clamped together to separate the feed solution and the stripping solution of a dialysis cell, was constructed. The urea in the feed solution passed through the anion-exchange membrane, water film, and then was hydrolyzed to ammonium carbamate in the urease-immobilized PVA membrane. The experimental results showed that no ammonium ion was found in the feed solution under either phosphate or citrate buffer systems at 0.05-0.2 mol/dm 3 and pH 6-9, and various initial concentrations of urea in the feed solution (20-200 mmol/dm 3 ). This indicates that the water film between two membranes allows the carbamate ions to decompose into ammonium and carbonate ions completely before entering the anion-exchange membrane. The device therefore can be used for the removal of urea from feed solution, while preventing the backflow of ammonium ions from the stripping solution or water film into feed solution. It has significant potential in the development of a wearable or portable artificial kidney. The properties of the urease-immobilized PVA membrane were examined. A kinetic model describing the transport-reaction behavior of urea in the membrane reactor-separator was developed, and the optimum values of the reactor parameters were obtained

Journal ArticleDOI
TL;DR: The index patients without parenteral exposure appeared to have acquired the disease from HCV‐infected family members with risk factors, indicating a higher anti‐HCV prevalence among family contacts than among the general population in Taiwan.
Abstract: To evaluate the intrafamilial transmission of hepatitis C virus (HCV) 104 index patients with type C chronic liver disease and their 307 family contacts were interviewed. After a questionnaire on the risk factors of parenteral exposure, blood samples were obtained and tested for liver biochemistry and anti-HCV antibody by enzyme-linked immunosorbent assay (Abbott II). Overall, 52 family contacts (17%) were positive for anti-HCV, indicating a higher anti-HCV prevalence among family contacts than among the general population in Taiwan. The anti-HCV prevalences in parents, spouses, children, and other contacts of the patients were 54% (14/26), 28% (25/91), 6.9% (10/143), and 6.4% (3/47), respectively. The contacts of index patients had increasingly greater risk of HCV infection when they became older and had lived longer with index patients. All family contacts were divided into two groups categorized by whether the index patients had or did not have a history of parenteral exposure. Among 126 family contacts of the 42 patients without parenteral exposure, blood transfusion and surgery were the factors significantly associated with HCV infection in these family contacts (odds ratio = 7.26, 95% confidence interval = 2.32–32.67; odds ratio = 3.95, 95% CI = 1.29–12.11, respectively). Risk factors were not significantly associated with HCV infection among 181 family contacts of the 62 index patients with parenteral exposure. It is concluded that the index patients without parenteral exposure appeared to have acquired the disease from HCV-infected family members with risk factors. Most of the index patients had a history of parenteral exposure and in turn served as the source of the disease for family members. © 1994 Wiiey-Liss, Inc.

Proceedings ArticleDOI
20 Jun 1994
TL;DR: In this paper, an active power filter using synchronous detection was proposed to eliminate line current harmonics and compensate the reactive current component in an unbalanced three-phase power system.
Abstract: This paper presents an active filter using the synchronous detection method. The equal current synchronous detection method is applied to calculate the reactive and harmonic current compensation components for triggering an active power filter in an unbalanced three-phase power system. The simulation and experimental results show that active filter operation using the synchronous detection method is effective to eliminate line current harmonics and compensate the reactive current component. The merits of the proposed method are its capability to operate under an unbalanced three-phase system by perphase calculation, to avoid conversion error by force waveform calculation, to balance the unbalanced load and to accomplish good performance by very simple implementation. >