Showing papers by "Academia Sinica published in 1978"
62 citations
DOI•
20 Feb 1978TL;DR: In this article, the authors present a mechanical procedure for proving non-trivial theorems in elementary geometry even by hands using the Sturm theorem and a generalization of it.
Abstract: The idea of proving theorems mechanically may be dated back to Leibniz in the 17th century and has been formulated in precise mathematical forms in this century through the school of Hilbert as well as his followers on mathematical logic. The problem consists in essence in replacing qualitative difficulties inherited in usual mathematical proofs by quantitative complexities of calculations on standardizing the proof procedures in an algorithmic manner. Such quantitative complexities of calculations, formerly far beyond the reach of human abilities, have become more and more trivial owing to the occurrence and rapid development of computers. In spite of vigorous efforts, however, researches in this direction give rise quite often to negative results in the form of undecidable mathematical theories. To cite a notable positive result, we may mention Tarski's method of proving theorems mechanically in elementary geometry and elementary algebra. The methods of Tarski as well as later ones are largely based on a generalization of Sturm theorem and are still too complicated to be feasible, even with the use of computers. The present paper, restricted to theorems with betweenness out of consideration and based on an entirely different principle, aims at giving a mechanical procedure which permits to prove quite non-trivial theorems in elementary geometry even by hands.
52 citations
DOI•
20 Jun 1978TL;DR: In this paper, it was shown that P x (1,1) = (7.8342xC x )/(logx) 2, where x is a large even integer and p 1 is a prime.
Abstract: Let P x (1,1)be the number of primes p, satisfying the condition x-p=p 1 , where x is a large even integer and p 1 is a prime. In this paper, we shall prove P x (1,1)≤(7.8342xC x )/(logx) 2 ), where
47 citations
TL;DR: It was found by such criteria that estrone and estradiol-17β exist in shrimp ovary, and the former was the major compound.
45 citations
TL;DR: Five proteases designated as A1, A2, B, C and D were isolated from Euphausia superba by the succesive steps of ammonium sulfate fractionation, acetone precipitation, gel filtration and DEAE-Sephadex A-50 chromatography and purified to homogeneity in disc gel electrophoresis by means of rechromatography.
Abstract: Five proteases designated as A1, A2, B, C and D were isolated from Euphausia superba by the succesive steps of ammonium sulfate fractionation, acetone precipitation, gel filtration and DEAE-Sephadex A-50 chromatography, A1, B, C and D were purified to homogeneity in disc gel electrophoresis by means of rechromatography on the DEAE-Sephadex A-50 column. Studies on substrate specificity of these enzymes revealed that A2, B, C and D were trypsin-like enzymes and A1 a carboxypeptidase A. A1, B, C and D had molecular weights of about 24,000, 24,000 28,000 and 27,000; optimal pH at 9.0, 8.0, 7.5 and 7.5–8. 0; and optimal temperature at 48, 50, 55–60 and 55°C, respectively. The activity of B, C and D were not inhibited by sulfhydryl reagents and N-α-tosyl-L-phenylalanylchloro-methyl ketone, but inhibited by reducing agents, N-α-tosyl-L-lysylchloromethyl ketone and soybean trypsin inhibitor. The activity of protease A1 was stimulated 3.5 fold by cobalt, but inhibited by 3-indolepropionate and D-phenylalanine.
43 citations
23 citations
TL;DR: Callus induction and regeneration of Lemna gibba G3 has been achieved in tissue culture under defined conditions from fully developed fronds and a regenerated strain exhibited as slower growth rate but no distinct morphological features.
21 citations
TL;DR: In this article, a submerged apparatus consisting of a buoy, several horizontal contraction and expansion tubes (Venturi-type tubes) and a long pipe is used to pump the subsurface sea-water containing abundant nutrients to surface layer (50-100 m) by the dynamic of ocean currents.
19 citations
TL;DR: The deoxycytidylate methyltransferase has been isolated and purified from sonically disrupted cells of Xp12-infected Xanthomonas oryzae and a 214-fold increase in specific activity was obtained.
Abstract: The methods, chromatographic, spectrophotometric and tritium-release assay, were used and compared for the assay of deoxycytidylate methyltransferase. All three methods can be used for assay of this enzyme but the tritium-releasfe assay appears to be the most simple and convenient. With the help of dthis assay the deoxycytidylate methyltransferase has been isolated and purified from sonically disrupted cells of Xp12-infected Xanthomonas oryzae. Using a procedure that involves fractionation with streptomycin sulfate and ammonium sulfate, filtration through Sephades G-100 and chromatography on DEAE-cellulose, a 214-fold increase in specific activity was obtained.
The enzyme displays a narrow pH optimum at 6.0. Among the buffers tested, 6-morpholinoethane sulfonate with the addition of M2+ is the best. The enzyme can utilize dCMP and CMP as a substrate. The enzyme can also convert tetrahydrofolic acid into dihydrofolic acid. The Km value for dCMP is 31.3 μ and the Km value for tetrahydrofolic acid is 71.4 μ. There is no absolute requirement of ions for the activity of the enzyme; however, the presence of ions causes stimulating or inhibiting effects jon enzyme activity that are dependent on the variety and concentration of ions used.
18 citations
01 Jan 1978
TL;DR: Serum gonadotropin levels of carp (Cyprinus carpio) have been determined by means of radioimmunoassay through the whole reproductive process, particularly the female exhibited a significant and higher peak during the sexual behaviour and spawning and after the spawning, the serum gonadotropic levels have a quick drop down.
Abstract: The mixed pituitary glands of Cyprinus carpio, Carassius auratus, Hypophthalmichthys molitrix and Aristichthys nobilis were extracted with ethanol Then the crude gonadotropin was fractionated by chromatography on DEAE-cellulose and gel filtration Biological activity as assayed by ovulation test of the loach (Misgurnus anguillicaudatus) in vivo was recognized only in the second fraction (Sephadex G-100) Effective dose of induced ovulation was 1μg/g body weight The gonadotropin (SG-Ⅱ-2) exhibited a single band on polyacrylamide gel electrophoresis The determinable range of this gonadotropin radioimmunoassay was 01～16ngSerum gonadotropin levels of carp (Cyprinus carpio) have been determined by means of radioimmunoassay through the whole reproductive process Particularly the female exhibited a significant and higher peak during the sexual behaviour and spawning After the spawning, the serum gonadotropin levels have a quick drop down This investigation provided some new data for reproductive physiology of fish
14 citations
TL;DR: The biological activity of cardiotoxin was indeed affected by nitration, but the immunological activity was nearly intact even when all the tyrosine residues were nitrated, and the peptide conformation of the partially nitrated cardiot toxin changed remarkably.
TL;DR: Calli were induced from intact mature mature fronds of Lemna perpusilla 6746, under illumination, on Murashige-Skoog (MS) medium supplemented with 0.1 mg/l 2,4-dichlorophenoxyacetic acid (2, 4-D) and 10mg/lN 6 -(Δ 2 -isopentenyl)-adenine (2iP) as discussed by the authors.
TL;DR: A polypeptide cardiotoxin containing 60 amino acids with 4 disulfide bonds has been synthesized by the "fragment solid-phase" method using the Sephadex G-50 method.
TL;DR: In this article, the notions of stochastic observability and controllability are defined, and necessary and sufficient conditions for these properties to hold, are established, which reduce respectively to the complete observability when the original system degenerates to the deterministic one, and explicit expression of the linear minimum covariance estimates for the states as well as for the initial value are also given.
Journal Article•
TL;DR: It was found that in adult male rat after admi-nistration with gossypol in low effectivedosage (5mg daily for 4 weeks), themitochondria of the middle piece of the Spermatids became dilated during the late peroid of spermatogenesis.
Abstract: The testis of the rat was examinedwith the electron microscope. It wasfound that in adult male rat after admi-nistration with gossypol in low effectivedosage (5mg daily for 4 weeks), themitochondria of the middle piece of thespermatids became dilated during thelate peroid of spermatogenesis. Theresults demonstrated that in rat the mostsensitive elements for gossypol in se-miniferous tubules were spermatids ofmaturation stage.
TL;DR: A polypeptide containing 60 amino acids with 4 disulphide bonds, synthesized by the solid-phase method, was highly purifed by anticardiotoxin-Sepharose affinity chromatography following gel filtration and CM-cellulose chromatography.
Journal Article•
TL;DR: A line of human liver cell carcino-ma, designated as BEL-7402, has been established by the roller tube method and has been maintained in continuous cultivation for more 3 years and pre-served in liquid nitrogen for 2(1/2) years with structure and cellularmorphology strikingly similar to those of the original surgical specimen.
Abstract: A line of human liver cell carcino-ma, designated as BEL-7402, has beenestablished by the roller tube method.It has been maintained in continuouscultivation for more 3 years and pre-served in liquid nitrogen for 2(1/2) years. BEL-7402 cells were derived fromspecimen obtained during the surgicaloperation of a 53-year-old male patientwhose serum was AFP positive. Thespecimen was identified microscopicallyas primary liver cell carcinoma accom-panied with cirrhosis. Within 2 hours post operation culti-vation was carried out. The specimenwas first cut into small fragments(1-1.5 mm~3) 20-30 of which wereplanted on the chick plasma-coated wallof each roller tube. The medium forthe initial cultivation was Eagle's MEMsupplemented with 40% fetal calf serum(inactivated at 56℃ for 45 min.) con-taining in addition 200 units of penicillinand 200 micrograms of streptomycin perml. The growth rate of cells was ratherslow at the beginning. The first transferwas therefore not carried out until the107th day of cultivation when a haloof outgrowth of cells was observed onthe majority of the explanted tissuefragments. Both the fragments andoutgrowth were then loosened and tryp-sinized and the resulting cell suspensionthereafter grown by stationany mono-layer culture and subcultures in bottles.From the third transfer when the cellswere in culture for about 4 monthsonwards, the rate of proliferation of thecells increased considerably, and thetransfers were made every 6-7 days.With the increase in number of transfers,the cell population showed changes withfibroblastic type of cells decreasing steadi-ly while the epithelial type of cellsbecoming more and more abundant andpredominant, the number of cells usuallyincreased 15 to 20-fold between 2 trans-fers. By this time, the culture mediumwas switched to RPMI-1640 medium sup-plemented with 20% fetal calf serumand the usual amount of antibiotics.This line of cells is still proliferating ata fairly constant rate. Investigations on the characteristicsof BEL-7402 cells were made with the following results: 1) The doubling-timefor BEL-7402 cell population is 20 hoursas estimated from radioautographic obser-vations after pulse labelling with~3H-thymidine. 2) Morphologically, BEL-7402 cells can be classified into 3 groups,i.e. the polygonal epithelial cells whichpredominate and account for 95.9% ofthe cells, the spindle fibroblastic cellsand the giant cells which together ac-count for the remaining 2-3%. 3) Themitotic index, including normal andabnormal mitoses, as determined bycounting 2,000 cells daily, from 2ndday-8th day, showed an increase to asmuch as 70‰ on the 4th day and thengradually decreased to 10‰ on the 8thday. The percentage in metaphase from4th day onwards was higher than otherstages of mitosis. 4) Chromosome ana-lysis based on observations of 103 me-taphase plates showed a wide variation.of chromosome number, with a modearound 60-63 (46.6% frequency). Ac-cordingly, this line of cells may be consi-dered to be hypotriploid. Another fea-ture observed is the presence of oneabnormally large acrocentric chromosomein 98% of the cells. 5) When the cellsuspension of BEL-7402 cell prepared in3 different concentrations, inoculatedto conditioned newly weaned male Wistarrats, all of them produced tumor nodulesin 8-10 days with structure and cellularmorphology strikingly similar to thoseof the original surgical specimen fromthe patient. 6) When the immunofluo-rescent indirect method was adapted forthe AFP detection the results showedthat this line of liver carcinoma cellswhich had been cultured in vitro formore than 2 years (128 passages) stillpossessed the ability to synthesize AFPintracellularly. 7) Histochemically, stain-ing reaction for TAT, G6PD and LDHenzyme activities of this line of cells aresimilar to those of the surgical specimenof liver carcinoma and differ from thenormal liver. Some of the results arediscussed.
TL;DR: With the assumption of dipole interaction with the membrane matrix, the dipole barrier under an applied field shows a minimum in its time transient.
TL;DR: Refolding of a denatured protein obtained by reducing cardiotoxin from the Taiwan cobra with mercaptoethanol has been carried out in aqueous and non-aqueous solutions and resulted in an active protein which showed identical conformation and biological activities such as lethality, antigenicity and muscle contracture inducing activity.
TL;DR: In this paper, it was shown that the formation of the penumbral filaments of a sunspot may be caused by the anti-clockwise spin of the sunspot, and the direction of both rotations was opposite to that of the effect of the differential rotation.
TL;DR: In this paper, 0.25 M of cystine in 1.5 N HC1 as cathode solution was divided by anion-exchange membrane from anode solution (1.5N HC1).
Abstract: Cysteine hydrochloride was prepared by electroreduction of cystine with stainless steel plate as electrodes. 0.25 M of cystine in 1.5 N HC1 as cathode solution was divided by anion-exchange membrane from anode solution (1.5 N HC1). A current of 5.6 A/S was applied and at the end of reaction, crysteine hydrochloride was obtained by evaporation of the cathode solution. The method is more convenient than the existing method.
Journal Article•
TL;DR: It is suggested that the "trigger" of parturition may be present in the tissue between the amniotic epithelium and syncytiotrophoblasts rather than in the maternal side of thesyncytio-trophoblast, and the serum levels of HPL or HCG decline in the same manner.
Abstract: It has been proved that Trichosan-thin is very effective in abortion in-duction of midtrimester gestation, andexerts its action directly on the placentalsyncytiotrophoblasts and possesses acertain degree of specificity. However,the mechanism to induce uterine con-traction and parturition is still unclear. By using the method of radioim-munoassay, it has been found that: (1) The drug appears and thendisappears rapidly from maternal bloodand urine after muscular injection (seeFig. 1-2), but it can not be detectedin the amniotic fluid and fetal blood. (2) After intraamniotic instilla-tion, the drug maintains approximatelyits initial high concentration in theamniotic fluid and fetal blood untilparturition, while it can never bedetected in the maternal blood. (3) However, whatever the routeof administration is, the effects ofTrichosanthin on the function of syncy-tiotrophoblasts are the same, the serumlevels of HPL or HCG decline in thesame manner (see 4-7). (4) In addition, results obtainedfrom the permeability experiment ofTrichosanthin through the amnion sacin vitro demonstrate that the drugcan penetrate the amniotic epitheliumand tissue surrounding it, but in a verylow concentration. (5) Since the time interval fromthe beginning of treatment to the endof parturition was found shorter inintraamniotic than in intramuscularadministration, and there is no correla-tion between the time interval and thefunctional change of syncytiotropho-blasts, it is suggested that the "trigger"of parturition may be present in thetissue between the amniotic epitheliumand syncytiotrophoblasts rather thanin the maternal side of the syncytio-trophoblasts.
TL;DR: A merit function entirely in terms of ray tracing is defined, which reflects well the performance of an optical system and can, in principle, be applied to optical systems.
TL;DR: In this article, the deformation and failure of a rock mass subjected to engineering load are essentially controlled by its internal structure, so that the study of rock mass structures should be considered as a foundation on which to understand its behaviour.
Abstract: The deformation and failure of a rock mass subjected to engineering load are essentially controlled by its internal structure, so that the study of rock mass structures should be considered as a foundation on which to understand its behaviour. Accordingly, in this paper, rock mass structures are classified into 4 types: intact blocky structures, layered structures, fractured structure, and loosened structure, and a rock mass quality, Z, is being proposed to evaluate the engineering geological behaviour of rock mass: Z = I. f. S. where I is intactness of rock mass; f is the frictional coefficient of predominant structure surfaces; S is the stiffness of the rock block.
TL;DR: In this article, a comparative static analysis of intra-urban location and land use is presented, in which it is shown that the intraurban optimum location is a function of the wage rate, the transport rate on the final product, the elasticity of demand, the population of the city and the income (or wealth) of a city.
Abstract: It is well-known that theories of urban land use and location, set forth by von Thunen and his followers, explained quite successfully the agricultural and residential locations Unfortunately, there has been virtually no comparative static analysis performed to probe their underlying properties The present paper attempts accordingly to take further steps in the direction of generalizing the theory of intra-urban location and land use and to present a general comparative static analysis It will be shown that, in general, the intra-urban optimum location is a function of the wage rate, the transport rate on the final product, the elasticity of demand, the population of the city and the income (or wealth) of the city In the process, it is demonstrated that characteristics of production function are crucial in conducting our comparative static analysis
TL;DR: DPX-3778, the triethanolamine salt of 3-(p-chlorophenyl)-6-methoxy-s-triazine-2,4(1H,3H) dione, enhanced ca.
Abstract: DPX-3778, the triethanolamine salt of 3-(p-chlorophenyl)-6-methoxy-s-triazine-2,4(1H,3H) dione, at concentrations of 0.124–2.48 μM enhanced ca. 4-5-fold the proliferation of tobacco (Nicotiana tabacum L. cv. Wisconsin 38) callus cultured in the presence of indole-3-acetic acid and kinetin, and retarded its senescence.
TL;DR: In this article, a series of corrector systems for Cassegrain telescopes automatically with an electronic computer were designed and compared under two conditions: the primary and secondary mirrors have strictly conical surfaces, and the telescope is strictly free from third-order spherical aberration when the corrector system is taken off.
DOI•
20 May 1978TL;DR: In this article, the authors reported the results of using inorganic semiconductor ZnO instead of chloroplast to reduce NADP to NADPH and phosphorylate ADP to ATP in the near ultraviolet light.
Abstract: In the previous papers, we reported the results of using inorganic semiconductor ZnO instead of chloroplast to reduce NADP to NADPH and phosphorylate ADP to ATP in the near ultraviolet light. From the facts that chloroplasts in photosynthesis can utilize the red section of the visible light and the yellow-green section proves itself the strongest part of sun light on the surface of earth, we succeeded in reducing NADP and synthesizing ATP under the action of visible instead of ultraviolet light by means Of new inorganic semiconductors. This paper reports the evidences of reduction of NADP and synthesis of ATP in the visible light with the help of a specially prepared cadmium sulfide (CdS). Furthermore, CdS can also reduce NADP to NADPH and phosphorylate ADP to ATP in the red light, which is in aocord with the electron theory of catalysis of photosynthesis. This affords a further evidence that the proposed theory is applicable to photosynthesis catalyzed by chloroplast which acts as a semiconductor.