Showing papers by "National Tsing Hua University published in 1981"
TL;DR: It is suggested that the toxicity of pure phospholipases is primarily due to a direct effect which does not correlate with levels ofospholipid hydrolysis and that this direct effect is prominent in the relatively toxic phospholIPases while it is less manifest in the comparatively non-toxic enzymes.
97 citations
TL;DR: The results support the view that catalytic activity is essential for toxic action as well as all other biochemical and physiological parameters studied.
82 citations
TL;DR: Levels and patterns of phospholipid hydrolysis in heart, lung and kidney following iv administration suggest that only the N. nigricollis enzyme has the ability to penetrate permeability barriers in the heart.
80 citations
TL;DR: The results show a clear dissociation between enzymatic activity and lethal toxicity, and the emission intensity of 8-anilinonaphthalenesulfonate-enzyme complex was altered by increasing concentrations of Ca 2+ , and different results were observed at different pH values of the buffer solution, indicating that Ca 2- causes pH-dependent conformational changes.
78 citations
01 Jan 1981
TL;DR: Clustering analysis is a newly developed computer-oriented data analysis technique that is a product of many research fields: statistics, computer science, operations research, and pattern recognition.
Abstract: Clustering analysis(1–4) is a newly developed computer-oriented data analysis technique. It is a product of many research fields: statistics, computer science, operations research, and pattern recognition. Because of the diverse backgrounds of researchers, clustering analysis has many different names. In biology, clustering analysis is called “taxonomy”.(5,6) In pattern recognition(7–15) it is called “unsupervised learning.” Perhaps the most confusing name of all, the term “classification” sometimes also denotes clustering analysis. Since classification may denote discriminant analysis, which is totally different from clustering analysis, it is perhaps important to distinguish these two terms.
77 citations
TL;DR: It is concluded that, while all phospholipases are likely to inhibit coagulation if used in amounts sufficiently large to deplete plasma ofospholipids, strongly active phospholIPases, such as N. nigricollis, interfere nonenzymatically with the clotting process before any appreciable phospholipsid hydrolysis is reached.
Abstract: The anticoagulant effects and the simultaneous plasma phospholipid hydrolysis induced by three purified phospholipases obtained from snake venoms, i.e., the basic, relatively toxic N. nigricollis, the neutral, relatively nontoxic H. haemachatus, and the acidic, relatively nontoxic N. n. atra, have been compared. The N. nigricollis phospholipase has a very strong anticoagulant effect at concentrations which induce relatively low levels of phospholipid hydrolysis in plasma. The H. haemachatus and N. n. atra phospholipases become anticoagulant only at high concentrations, and the associated phospholipid hydrolysis is also very high. It is concluded that, while all phospholipases are likely to inhibit coagulation if used in amounts sufficiently large to deplete plasma of phospholipids, strongly active phospholipases, such as N. nigricollis, interfere nonenzymatically with the clotting process before any appreciable phospholipid hydrolysis is reached.
57 citations
TL;DR: In this paper, the authors investigated the effect of NO impurity in the methane feed on the decomposition of ThO 2 SiO 2 surface at 1073 K. Positive catalytic effect on decomposition has been confirmed at low reaction conversions when ethane and ethylene are major products.
50 citations
TL;DR: In this article, experimental techniques for growing CuInS2 layers on GaP substrates by the metalorganic method have been developed, where hydrogen sulfide gas together with the vapors of CuCl(NCCH3)n and InCl3S2 both of which were generated by bubbling nitrogen through sources, using a solvent of acetonitride, were used as transport agents.
48 citations
TL;DR: In this paper, the authors show that poly(vinyl chloride) and poly(acrylonitrile-co-butadiene) can be used to replace rubber polymers.
Abstract: Mixtures of two compatible polymers, poly(vinyl chloride) and poly(acrylonitrile-co-butadiene) containing 40 percent acrylonitrile, can be compatible with poly(vinylidene chloride-co-vinyl chloride), which is incompatible and partially compatible respectively with these two polymers. The crystalline melting temperature and relative heat of fusion of poly(vinylidene chloride-co-vinyl chloride) in blends are higher than those in the pure component. This is attributed to greater ordering of the polymer chains in the crystalline phases of the blends. Replacing the rubber by poly(acrylonitrile-cobutadiene) containing 30 percent acrylonitrile, shows that these three polymers, in which each pair is incompatible or at most partially compatible, also form compatible ternary blends. The crystalline melting temperature is higher and relative heat of fusion lower than those in the pure component. This is attributed to dissolving of parts of the polymer chains originally located in the crystalline phases in the amorphous phases of the blends.
45 citations
TL;DR: In this paper, the constituents of three Costa Rican ferns of Pteridaceae were investigated, and a new pterosin-type compound (I), named jamesonin, along with two pterusin derivatives and six ent-kaurane-type diterpene derivatives were isolated, and I was established as (2R, 3R)-3-hydroxy-6-(2 -hydroxyethyl)-2, 7-bishydroxymethyl-2, 5-dimethylindan-1-one.
Abstract: The constituents of three Costa Rican ferns of Pteridaceae were investigated. From Jamesonia scammanae A. TRYON, a new pterosin-type compound (I), named jamesonin, along with two pterosin derivatives and six ent-kaurane-type diterpene derivatives were isolated, and I was established as (2R, 3R)-3-hydroxy-6-(2-hydroxyethyl)-2, 7-bishydroxymethyl-2, 5-dimethylindan-1-one by spectroscopic methods. From Dicksonia gigantea KARST., two known pterosin derivatives were isolated, and from Paesia anfractuosa C. CHR., two flavonol glycosides.
36 citations
TL;DR: In this paper, the Doppler shift of quasifree electron bremsstrahlung (QFEB) induced by 20-MeV-proton bombardments of a Be target has been measured with a Si (Li) detector.
Abstract: Energy spectra and angular distributions of quasifree electron bremsstrahlung (QFEB) induced by 20-MeV-proton bombardments of a Be target have been measured with a Si (Li) detector. The Doppler shift of QFEB is clearly observed in the energy spectra and depends on the observation angle. The production cross section calculated from a free-electron approximation is compared with the experimental result and the agreement is quite satisfactory. The spectral shape near the high-energy end point of the QFEB definitely reflects the velocity distribution of the orbital electrons of the target atom. Angular distributions of secondary-electron bremsstrahlung were also measured and are compared with a calculation which includes relativistic retardation effects.
TL;DR: The solution of linear piecewise constant delay systems has been derived by using the block pulse series expansion method with a matrix called the delay operational matrix introduced first to manipulate the time delay.
Abstract: The solution of linear piecewise constant delay systems has been derived by using the block pulse series expansion method. A matrix called the delay operational matrix is introduced first to manipulate the time delay. Then the solution is obtained through using the matrix and the properties of block pulse functions.
TL;DR: In this article, two known and five new ent-kaurane type diterpenes were isolated from the fronds of Pteris longipes and the structures of the new diterphenes, pterokaurene L1, L2, L3, L4 and pterokaurane L5, were established respectively as ent-9-hydroxy-15-oxo-Kaur-16-en-19-oic acid, ent-11α, 16α-epoxy-16Rkauranoic acid and
Abstract: From the fronds of Pteris longipes DON two known and five new ent-kaurane type diterpenes were isolated. The structures of the new diterpenes, pterokaurene L1, L2, L3, L4 and pterokaurane L5, were established respectively as ent-9-hydroxy-15-oxo-kaur-16-en-19-oic acid, ent-9, 15α-dihydroxy-kaur-16-en-19-oic acid, ent-9-hydroxy-kaur-16-en-19-oic acid, ent-12α, 15α-dihydroxy-kaur-16-en-19-oic acid and ent-11α, 16α-epoxy-16R-kauranoic acid by spectroscopic methods, some chemical transformations and X-ray crystallographic analysis.
TL;DR: The most basic and toxic phospholipase A 2 purified from Naja nigricollis venom was subjected to lysine modification with cyanate at pH 8.0 and it is clear that the different conformational changes induced by Ca 2+ might be attributable to the charge properties of the enzyme, which depend on the pH of the solution and the pI of the enzymes.
TL;DR: In this paper, a set of general differential equations were used to describe the dynamics of an adiabatic controlled cycled stirred tank (CCTR) this paper and the observed dynamic and pseudo steady state behavior agreed very well with predictions from theory.
TL;DR: It is concluded that, while modification of a catalytically essentialArginine abolishes pharmacological properties, the other arginine residues are little or not involved in pharmacological effects.
TL;DR: In this paper, an elastodynamic hybrid-displacement finite element model is developed to deal with problems involving bi-material cracked structures subjected to dynamic loadings, which is based on a modified Hamilton's principle with relaxed continuity requirements for displacements at the interelement boundary, the mass and stiffness properties of circular sector shaped singular elements embedded with the proper stress singularities at the bimaterial imperfection fronts are derived.
TL;DR: A red crystal of [Cu(trans-[14] diene)]2+ (ClO4−)2 was crystallized from a methanol-water or acetone-water solution by slow evaporation of the solvent as discussed by the authors.
TL;DR: In this paper, low cycle fatigue studies have been carried out on 2 wt% Mn, 2wt% Si and 0.1 wt % C steels with dual-phase and tempered martensitic structures.
Abstract: Low cycle fatigue studies have been carried out on 2 wt% Mn, 2 wt% Si and 0.1 wt% C steels with dual-phase and tempered martensitic structures. Fatigue crack initiation and propagation were investigated using scanning electron microscopy as well as optical microscopy. In addition, taper-section and cross-section techniques were also performed for more detail studies on the correlation of crack initiation with the internal microstructures of the testing samples. Internal microstructures were also investigated on the dual-phase steel sample before and after fatigue fracture by transmission electron microscopy.
TL;DR: In this paper, a new norcarotenoid glycoside was isolated and shown to be (6R, 7E, 9R)-9-hydroxy-megastigma-4, 7-dien-3-one-9-O-β-D-glucoside.
Abstract: From the fronds of Polystichum tripteron (KUNZE) PR. a new norcarotenoid glycoside was isolated and shown to be (6R, 7E, 9R)-9-hydroxy-megastigma-4, 7-dien-3-one-9-O-β-D-glucoside. The fronds of Dennstaedtia wilfordii (MOORE) CHRIST. contain the same glucoside.
TL;DR: From the fronds of Pteris purpureorachis COPEL, three new entatisane type diterpenes, pteroatisene P1, P2 and Pteroatisenoside P1 were isolated as mentioned in this paper.
Abstract: From the fronds of Pteris purpureorachis COPEL. three new ent-atisane type diterpenes, pteroatisene P1, P2 and pteroatisenoside P1, were isolated. Their structures were elucidated using some chemical transformations, spectroscopic methods and X-ray crystallographic analysis as ent-9-hydroxy-15-oxo-atis-16-en-19-oic acid, ent-9, 15α-dihydroxy-atis-16-en-19-oic acid and ent-9-hydroxy-15-oxo-atis-16-en-19-oic acid-β-D-glucosylester.
TL;DR: In this paper, simple approximation formulas for the mean squared errors of the minimum variance unbiased and the maximum likelihood estimators of reliability of a system with m independent components are provided. But the performance of the proposed approximation formulas is investigated.
Abstract: Suppose S is a system with m independent components such that the system functions if and only if at least k components operate. Assume that the component lifetimes are identically exponentially distributed. This work provides simple approximation formulas for the mean squared errors of the minimum variance unbiased and the maximum likelihood estimators of reliability of this system. The performance of the proposed approximation formulas is investigated.
TL;DR: In this paper, a finite element solution to the problem of low Peclet number fluid flow in the thermal entrance region of a round pipe is presented, where the velocity is assumed to be laminar and fully developed throughout the pipe and the fluid temperature is kept uniform atX = ∞.
Abstract: This paper presents a finite element solution to the problem of low Peclet number fluid flow in the thermal entrance region of a round pipe. The velocity is assumed to be laminar and fully developed throughout the pipe and the fluid temperature is kept uniform atX = —∞. The pipe wall is adiabatic at X ≤ 0 and cooled convectively at X ≥ 0.
The solutions include temperature distributions and Nusselt numbers for the parameters, Bi = 0.04, 0.4, 4, 20 and Pe = 1, 3, 5, 10, 20, 30, which are in excellent agreement with the existing analytic solution except in the region near the singular point Δ A temperature discrepancy in the analytic solution at this point is physically impossible. The finite element method overcomes this mathematical difficulty and shows a greater value in the Nusselt number due to a higher wall temperature at X ≥ 0.
On presente, dans le travail, une solution utilisant une methode d'elements finis pour le probleme de l'ecoulement d'un fluide a faibles nombres de Peclet dans la region d'entree thermique d'un tube rond. On suppose que la vitesse est laminaire et etablie d'un bout a l'autre du tube et que la temperature du fluide est maintenue uniforme a X = — ∞. La paroi du tube est adiabatique a X ≤ 0 et elle est refroidie d'une maniere convective a X ≥ 0.
Les solutions comprennent des distributions de temperatures et des nombres de Nusselt pour les parametres Bi = 0.04, 0.4, 4, 20 et Pe = 1, 3, 5, 10, 20, 30, elles concordent tres bien avec la solution analytique existante, sauf dans la region a proximite du point singulier X = 0, r = 1; il est physiquement impossible d'obtenir une difference de temperature dans la solution analytique en ce point. La methode des elements finis remedie a cette difficulte mathematique et fournit un nombre Nusselt de aleur plus grande, par suite d'une temperature plus elevee de la paroi a X ≥0.
TL;DR: In this article, the experimental cumulative yields of the thermal neutron fission of /sup 235/U have been measured by the gas chromatographic method and the independent yields of Xe isotopes plus the reported data, the Xe-isotopic distribution curve has been constructed.
Abstract: The experimental cumulative yields of /sup 85/Kr/sup m/, /sup 87/Kr, /sup 88/Kr, /sup 133/Xe/sup g/, /sup 135/Xe/sup m/, and /sup 135/Xe/sup g/ and the independent isomeric yield of /sup 133/Xe/sup m/ in the thermal neutron fission of /sup 235/U have been measured by the gas chromatographic method. The independent yields of /sup 133/Xe/sup g/, /sup 135/Xe/sup m/, and /sup 135/Xe/sup g/ were deduced with the aid of /sup 133/I and /sup 135/I data. The isomeric yield ratios of /sup 133/Xe and /sup 135/Xe have been computed and compared with theoretical values since they have the same high spin state J = 11/2/sup -/ and low spin ground state J = 3/2/sup +/. The influence of the shell effect on the fission isomeric yield ratio is discussed. From the measured independent yield of Xe isotopes plus the reported data, the Xe-isotopic distribution curve has been constructed. The curve is compared with the isotopic distribution curves of Xe isotopes formed in 11.5 GeV proton interactions with /sup 238/U and Cs isotopes formed in 24 GeV proton interactions with /sup 238/U. Upon fitting the yield curves we find that only those products with N/Z> or =1.48 fit a curve typical of a binarymore » fission process.« less
TL;DR: In this article, an assumed hybrid displacement finite element model is presented to deal with elastodynamic cracked problems, based on a modified Hamilton's principle with relaxed continuity requirements for displacements at the inter-element boundary, the mass and stiffness matrix of singular elements embedded with proper singularity near the crack-tip are derived.
TL;DR: In this article, the detection limit of PIXE using protons of 3, 6, 9, and 12 MeV was estimated on the basis of measured background X-ray spectra and K and L Xray production cross sections.
TL;DR: In this article, the detection limit of PIXE has been estimated as a function of the detection angle and atomic number of the element to be detected; the measurement at an angle of θ L ⩾ 135° is found to be favorable to obtain high sensitivity.
TL;DR: Theoretical models used to describe the interaction of electrons with the valence band of insulators are discussed in this article, and the results for the application of these models to calculate stopping power and mean-free path of low-energy electrons (< 10 keV) in diamond are presented.
Abstract: Theoretical models used to describe the interaction of electrons with the valence band of insulators are discussed. Results for the application of these models to calculate stopping power and mean-free path of low-energy electrons (< 10 keV) in diamond are presented. The influence of core polarizability, oscillator strength coupling between core and valence electrons, and exchange corrections is included. The contributions to the mean-free path and stopping power from ionization of inner shells have been evaluated from sum-rule-constrained classical binary-collision model.