bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tonic nicotinic transmission enhances spinal GABAergic presynaptic release and the frequency of spontaneous network activity
Authors: Gonzalez‐Islas Carlos , Garcia‐Bereguiain Miguel Angel , O'Flaherty Brendan , Wenner Peter 
Published: June 2015

ABSTRACTSynaptically driven spontaneous network activity (SNA) is observed in virtually all developing networks. Recurrently connected spinal circuits express SNA, which drives fetal movements during a period of development when GABA is depolarizing and excitatory. Blockade of nicotinic acetylcholine receptor (nAChR) activation impairs the expression of SNA and the development of the motor system. It is mechanistically unclear how nicotinic transmission influences SNA, and in this study we tested several mechanisms that could underlie the regulation of SNA by nAChRs. We find evidence that is consistent with our previous work suggesting that cholinergically driven Renshaw cells can initiate episodes of SNA. While Renshaw cells receive strong nicotinic synaptic input, we see very little evidence suggesting other spinal interneurons or motoneurons receive nicotinic input. Rather, we found that nAChR activation tonically enhanced evoked and spontaneous presynaptic release of GABA in the embryonic spinal cord. Enhanced spontaneous and/or evoked release could contribute to increased SNA frequency. Finally, our study suggests that blockade of nAChRs can reduce the frequency of SNA by reducing probability of GABAergic release. This result suggests that the baseline frequency of SNA is maintained through elevated GABA release driven by tonically active nAChRs. Nicotinic receptors regulate GABAergic transmission and SNA, which are critically important for the proper development of the embryonic network. Therefore, our results provide a better mechanistic framework for understanding the motor consequences of fetal nicotine exposure. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 298–312, 2016
Titanium‐Catalyzed [6π+2π]‐Cycloaddition of Alkynes and Allenes to 7‐Substituted 1,3,5‐Cycloheptatrienes
Authors: D'yakonov Vladimir A. , Kadikova Gulnara N. , Kolokol'tsev Dmitry I. , Ramazanov Ilfir R. , Dzhemilev Usein M. 
Published: June 2015

AbstractThe reaction of 7‐alkyl(allyl,phenyl)‐1,3,5‐cycloheptatrienes with alkynes and allenes, catalyzed by the two‐component Ti(acac)2Cl2–Et2AlCl system, resulting in the formation of substituted bicyclo[4.2.1]nona‐2,4‐dienes and bicyclo[4.2.1]nona‐2,4,7‐trienes in up to 90 % yield, was accomplished. The structures of the obtained compounds were confirmed by X‐ray diffraction and by 1H and 13C NMR spectroscopic analysis.
Hydrazones as Productive Dienophiles in the Inverse Electron Demand Diels–Alder Reactions of 1,3,5‐Triazines
Authors: Yang Kai , Yang Zhen , Dang Qun , Bai Xu 
Published: June 2015

AbstractEnamines, ynamines and amidines are common dienophiles for inverse electron demand Diels–Alder (IEDDA) reactions of 1,3,5‐triazines, however, their wide utilization may be limited due to their poor stability to conventional purification methods such as silica gel chromatography. To address this limitation, oximes and hydrazones are envisioned as potential alternative dienophiles, even though they are primarily used as protecting groups due to their excellent stability or lack of reactivity. Through investigation of substituent effects and optimization of reaction conditions, oximes and hydrazones were developed as productive dienophiles for 1,3,5‐triazine IEDDA reactions, leading to the desired IEDDA products in moderate (for oximes) to excellent (for hydrazones) yields. Hydrazones are air‐stable and can be conveniently purified by conventional methods, therefore the introduction of hydrazones as productive dienophiles further expanded the scope of 1,3,5‐triazine IEDDA reactions.
Triterpenoid. I. The Sugar Constituents of Some Triterpenoid Saponins from Formosan Plants
Authors: Lin Yau‐Tang , Lo Tung‐Bin , Tai Wun‐Ten 
Published: June 2015

AbstractThe sugar Parts of A2‐Barrinin(1), D1‐Randinin, C‐Momordin, F‐Styradin and S‐Styradin were investigated paper chromatographically, and a more accurate result was obtained.
Conjugated Unsaturated Ketones. III. Aromatization‐Like Reactions and Aromatization of Dibenzalcycloalkanones
Authors: Yeh Ping‐Yuan 
Published: June 2015

AbstractThe stability of 2,6‐dibenzalcyclohexanone (V) and 2,5‐dibenzalcyclopentanone (VI) has been discussed. Twenty‐seven examples of aromatizationlike reaction of 2,6‐dibenzalcyclohexanone and 2,5‐dibenzalcyclopentanone have been studied. Aromatization of 2,6‐dibenzalcyciohexanone has been realized by both indirect and direct methods.
Essential Oils. IV. Oil of Limnophila Erecta, Benth
Authors: Yeh Ping‐Hsien , Lin Chih 
Published: June 2015

AbstractLimnophila arecta, Benth. gave 0.05% essential oil on steam distillation. The crude oil consists of 37% α‐pinene, 15% d‐limonene, 26% α‐caryophyllene, 15% β‐caryophyllene, 4% cadinene, 2% sesquiterpene alcohols, and traces of terpene alcohol.
The Essential Oil of Chamaecyparis Taiwanensis, Masamune et Suzuki. I. Acidic components
Authors: Lin Yau‐Tang , Wang Kung‐Tsug , Chen Chen‐Loung 
Published: June 2015

AbstractThe lower boiling point fraction (b.p. ca. 130°/15 mm) of the essential oil of Chamaecyparis taiwanensis was thoroughly studied. p‐Cresol, α‐Thujaplicine and one new tropolonoid were newly identified as the additional components. 1‐Rhodinic acid, Hinokitiol and Terpin hydrate were also identified in this fraction.
Molecular Orbital Theory of Hyperconjugation. II. A Note on the Desmotropism of Pyrrole
Authors: Lin Wei‐Chuwan 
Published: June 2015

AbstractThe molecular orbital theory is applied to the treatment of the hyperconjugation in α‐and β‐pyrrolenines, the so‐called desmotropes of pyrrole. The results obtained are listed. Reseonance energies in both pyrrlenines are found to be in agreement with that of normal pyrrole. It is proposed that the desmotropism of this type corresponds to a kind of degeneracy in which each of the desmotropes may be considered as the unperturbed state.
Physico‐Chemical Studies on the Electrolytic Behavior of Thorium and Uranium Ions. I. Spectrophotometric Studies on Thorium and Uranyl Sulfosalicylates
Authors: Pan Kuan , Hseu Tong Ming , Chang Teh Liang 
Published: June 2015

AbstractMixtures of thorium and uranyl perchlorates and sulfosalicylic acid have been studied by potentiometric titration with sodium and ammonium hydroxides, respectively, using glass electrode as indicator electrode. No precipitation was observed in these titrations up to pH 8 in the presence of an excess of sulfosalicylic acid. The reaction between thorium and sulfosalicylate ions has been studied spectrophotometrically, using 1:1 uranyl sulfosalicylate complex as an indicator. The latter complex was reinvestigated at pH 3.7 for comparison. By employing Job's method of continuous variations, it was found that thorium and sulfosalicylate ions reacted in a 1:1 ratio at pH 3.7, showing that an exchange reaction had taken place between thorium salt and uranyl sulfosalicylate.
A Study in the Mechanism of the Formation of Substituted Uracils and Thiouracils
Authors: Ma T.S. , Zoellner William G. 
Published: June 2015

AbstractA variety of ureas and thioureas were treated with ethyl acetoacetate, ethyl n‐butylacetoacetate, and ethyl di‐n‐butylacetoacetate under acidic, basic, and neutral conditions. Under acidic conditions, ethyl acetoacetate reacted only with urea or methylurea; under neutral conditions, it reacted only with thiourea; under basic conditions, it reacted only with thiourea, methylthiourea and ethylthiourea. Ethyl n‐butylacetoacetate reacted only with thiourea in base, while ethyl di‐n‐butylacetoacetate failed to condense with urea or thiourea under all conditions.In the condensation reaction between acetoacetic ester and thioureas, it was found that (a) the reaction proceeded best with thiourea and ethyl acetoacetate; (b) introduction of a single alkyl group into either the thiourea or the acetoacetic ester molecular lowered the yield but did not preclude the reaction; (c) introduction of two alkyl groups distributed in any fashion between the thiourea and acetoacetic ester molecules precluded the reaction; and (d) only the 3‐alkyl thiouracils were obtained from alkyl thioureas. A probable mechanism, based on the resonance theory, has been proposed.
Studies of the Polymerization of Vinyl Acetate in the Aqueous Solutions of Partially Acetylated Polyvinyl Alcohol. II. On the Change of Huggins' Constant k′ with the Variation of the Composition of the Mixed Solvent
Authors: Lin Chen‐Chong 
Published: June 2015

AbstractThe change of Huggins' constant k′ of the graft polymer solution brought about by varying the composition of the solvent was studied. The graft polymer solution studied was prepared according to the method described in the author's previous paper,(1) and k′ was obtained from viscosity measurements of the solvent with varying methanol contents. The following results were obtained:(1) The Huggings' constant was found to change with the variation in the methanol content of solvent.(2) The minimum value for k′ was attained when the solvent contained 75% methanol.(3) The first interaction coefficients a2 were determined and the critical point was also observed under the same conditions.
Cathodic Action of the Metal Complexes at the Dropping Mercury Electrode. VII. Lead‐Ascorbate Complex
Authors: Lai Tsai‐Teh , Wang Bi‐Cheng 
Published: June 2015

AbstractThe polarographic characteristics of the chelate formed between lead ion and ascorbic acid have been studied over a pH range of 2.0 to 5.8.The reversible reduction was held over a wide range of the concentration of the chelating agent varying from 0.132 M to 1.0 M when pH value was lower than 5.8.The higher the concentration of ascorbic acid, the more hydroxylion was involved in the reduction of the polarographic solution of the same pH value.At pH 2.5 to 5.8 the existence of a mixture of more than one kind of chelate species was found.The diffusion current was found to be proportional to lead ion concentration from 0.2 mM to 2.0 mM with 1.4% average deviation.
Extractive Components from the Heartwood of Taiwania Cryptomerioides Hayata. II. The Presence of Hinokiol, Savinin and α‐Cadinol
Authors: Lin Yau‐Tang , Lin Yaw‐San , Lo Tung‐Bin 
Published: June 2015

AbstractIn part I of this series,(1) we reported that four kinds of crystalline components had been isolated from the acetone extract of the wood.
Cholesteroxytrimethylsilane and Stigmasteroxytrimethylsilane
Authors: Liu Sheng‐Lieh , Wang Taitzer 
Published: June 2015

AbstractAlthough a great number of alkoxyorganosilanes have been reported in the last two decades, not a single organosilane containing a steroid skelton in the alkoxy part of the compounds of RO‐SiR3' type is known. Intending to get some information concerning such compounds, cholesterol, stigmasterol, and ergosterol were separately treated with trimethylchlorosilane in the presence of pyridine, as a hydrochloric acid acceptor, to form the corresponding trimethylsilylethers. Only cholesterol and stigmasterol, however, gave stable compounds. In the case of ergosterol the trimethylsilyl ether formed at first hydrolyzed easily during recrystallization. The two stable crystalline ethers can also be hydrolyzed by prolonged contact with water vapor. Thus the trimethylsilylethers of sterols are different from those of xylenols(1,3) whose stability toward water was described previously.
Some Aspects on the Preparation of Rubidium‐86
Authors: Yang Mo‐Hsiung , Yeh Si‐Jung 
Published: June 2015

AbstractA systematic study on the purification of Rubidium‐86 was carried out. Ten grams of rubidium chloride was irradiated in the THOR for 120 hours at the neutron flux of 3×1012 n/cm2‐sec. After the anionic species induced by nuclear reactions were removed by anion exchange resin, the trace amount of cesium contaiminated in the irradiated target was separated from rubidium‐86 by ion exchange method. Dowex 50w×4(200–400 mesh) was used as the exchange resin and dilute hydrochloric acid of varying concentrations was employed as the eluant. Optimum conditions for separating a large quantity of rubidium‐86 from the trace amounts of cesium‐134 was investigated by varying column ratios, hydrochloric acid concentrations and flow rates. An inorganic exchanger was also tried for comparison.
Cellophane Dosimetry of Electron Beam Generated by Van de Graaff Accelerator
Authors: Chem Tsan‐Jen , Yeh Si‐Jung 
Published: June 2015

AbstractThe dose of electron beam generated by Van de Graaff accelerator was measured by using ceric‐cerous dosimeter. Two kinds of cellophane dosimeters (Type A and Type B) were also used to provide a simple means for routine measurement of the dose of an electron beam. It was demonstrated that a linear relationship existed between optical density changes of cellophane dosimeter and the total dose of electron beam in the range of 2.0×105−8×106 (Type A) and 2.0×106−6×107 (Type E) rads, respectively.
Methylbutylhydrosiloxanes
Authors: Liu Sheng‐Lieh , Chen Cheng‐Yu 
Published: June 2015

AbstractPartial butylation of methyldichlorosilane followed by the hydrolysis of the product gave a complicated siloxane mixture, from which 1,3‐dimethyl‐1, 3‐dibutyl‐1, 3‐dihydrosiloxane (I), 1,3,5‐tri‐methyl‐1, 5‐dibutyl‐1, 3,5‐trihydrotrisiloxane (II), and 1,3,5,7‐tetra‐methyl‐1,7‐dibutyl‐1,3,5,7‐tetrahydrotetrasiloxane(III) were isolated and structurally determined. Removal of unreacted methyldichlorosilane after coupling reaction caused better yield of disiloxane, retention of methyldichlorosilane caused abundant yield of polysiloxanes.
Polyamide‐Silica Gel Mixed Layer Chromatography of Water Soluble Vitamins
Authors: Chiang Hung‐Cheh , Wu Ying‐Chang 
Published: June 2015

AbstractThe water soluble vitamins were well separated on the polyamide‐silica gel G(2: 1) mixed layer with 10% ammonium chloride solution, 10% sodium citrate solution, and 10% sodium sulfate solution. The mixed layer is firmly bonded and easy to handle and store.
Syntheses of 9‐β‐D‐Ribofuranosylpurine Derivatives as Effective Antiradiation Agents
Authors: Lee Kong‐Ko 
Published: June 2015

Abstract6‐(2‐Hydroxyethyl‐1, 2‐14C) amino‐9‐β‐D‐ribofuranosylpurine (I) and 6‐(2‐mercaptoethyl‐35S) amino‐9‐β‐D‐ribofuranosylpurine (II) were synthesized for the investigation of their in vivo distribution in mice. All the reaction conditions were made by non‐radioactive runs and it was found that thiol compound II was easily oxidized to form the disulfide IV in the purification procedure.
Studies on the Alkaloids of Formosan Corydalis Species: Part III. Alkaloids of Corydalis Tashiroi Makino
Authors: Lu Sheng‐Teh , Lin Chun‐Nan , Wu Tien‐Shung 
Published: June 2015

AbstractSix alkaloids have been isolated from Corydalis tashirol Makino and four of these were identified as palmatine(I), dl‐tetrahydropalmatine(III), I‐tetrahydropalmatine(III) and protopine(V).
Polarized Raman spectra IX. Low Frequency Vibrations in Crystallne Trans‐Stilbene
Authors: Ting Chen‐Hanson 
Published: June 2015

AbstractRaman spectrum of powdered crystalline trans‐stilbene is recorded by a laser Raman spectrometer. The intensity of a low frequency skeleton bending vibration at 220 cm−1 is observed to be very weak. Its Raman intensity, after corrected for the photocathode response and for the v4 scattering factor, agrees within 10% of the theoretically calculated value. It is therefore proved that the intensity of a Raman active vibration is proportional to the square of its vibrational frequency, if only one excited state is involved in the scattering process.Lattice vibrations in trans‐stilbene crystal are also reported.
Studies on the Alkaloids of Formosan Lauraceous Plants. XVII. Alkaloids of Phoebe Formosana Hay. 1
Authors: Lu Sheng‐Teh , Su Tsann‐Long 
Published: June 2015

AbstractNine alkaloids have been isolated from the woods and the barks of Phoebe formosana Hayata and four of these have been identified with laurolitsine) (IV), roemerine (V), ushinsunine (VI) and oxoushinsunine (liriodenine) (VII).
NMR Studies of Solvent Effect on Internal Rotation in Some Non‐Symmetrical 1,2‐Disubstituted Ethanes
Authors: Chen Li‐Shu , Lin Wei‐Chuwan 
Published: June 2015

AbstractThe A2B2 system of PMR spectra of 3‐bromopropionic acid, 3‐chloropropionic acid, 3‐bromopropionitrile, and 3‐chloropropionitrile exhibit appreciable solvent effect at room temperature. NMR spectroscopic parameters of A2B2 spectrum as well as physical parameters related to internal rotation, i. e. the highest energy barrier and the energy difference between rotamers, were determined for these compounds in the medium of various solvents. It was found that in the case of 3‐bromopropionic acid, the trans rotamer is more stable than the gauche rotamers, and the energy difference decreases with increasing dielectric constant of solvent. While in the case of 3‐bromopropionitrile, the gauche rotamers were found to be more stable than the trans rotamer and the energy difference increases with increasing dielectric constant of solvent. In the remaining two compounds, 3‐chloropropionic acid and 3‐chloropropionitrile, both trans and gauche rotamers are equally stable in a solvent of low dielectric constant, however in a solvent of higher dielectric constant, the gauche rotamers become more stable than the trans rotamer and the energy difference becomes more pronounced with increasing dielectric constant of solvent.
Gas Chromatographic Determination of Trace Amount of Chromium
Authors: Yeh Si‐Jung , Ke Chin‐Nan 
Published: June 2015

AbstractTrace amount of chromium was first converted quantitatively to volatile chromium chelates such as chromium(III) acetylacetonate, Cr(acac)1, chromium(III) trifluoracetylacetonate, Cr(tfa)3, and chromium(III) hexafluoroacetylacetonate, Cr(hfa)3, and the chelate solution was then analyzed by gas chromatography. It was found that Cr(tfa)3 is the most suitable chemical form for this purpose. The method was profitably applied to the determination of chromium(III) incorporated in the six kinds of commerical products of potassium Chromate.
60Co‐v Radiolysis of a Mixture of Benzene and Cyclohexane in Presence of Diphenyl Mercury
Authors: Nazir S. B. , Rai R. S. 
Published: June 2015

AbstractIn the radiolysis of cyclohexane in presence of 4×10−3M diphenylmercury (Hg φ3) three isomers of hexane, methylcyclopentane (G=0.018), benzene (G=0.42) and cyclohexene (G=0.047) were detected. Addition of benzene in the mixture of cyclohexane and Hg φ3 formed two isomers of pentane, hexene and one isomer of hexane as additional products, while cyclohexene was eliminated completely. Normally, eight products were detected in presence of 10 to 50% benzene. Total radiolytic yield of products increased in presence of 15 to 25% benzene but in presence of 35 to 50% benzene G values became very low. Considerable amount of hexene is formed in a mixture of benzene and cyclohexane but neither benzene nor cyclohexane in presence of Hg φ2 formed this compound. In the presence o. benzene and φ2Hg hexane yield is very much reduced. Protection is observed in presence of 10% as well as 35 to 50% benzene in this system. The plot of benzene concentration in moles/litre versus methylcyclopentane is linear and from the slope of the straight line, the values of rate constants were found to be 2.65×10−2 litre/mole sec., 5.25×10−3 litre mole sec., 9×10−7 litre/mole sec. for methylcyclopentane, cyclohexane and benzene respectively. A plot of G(–c‐C6H12) versus 1/[C6H6] also gave a straight line which confirms the sponge type protection in this multicomponent system.
Assay and Kinetic Studies on the Enzymatic Proteolysis with Ninhydrin Reagent
Authors: Lai Tzen‐Son , Liao Mei‐June 
Published: June 2015

AbstractA method using ninhydrin reagent for proteolytic activity measurement and kinetic studies with protein or modified protein as substrate was explored. As the reagent is specific for amino group, quantitative expression can be made with the number of peptide bonds cleaved. The sensitivity of the method made it possible for the determination of various kinetic parameters such as Km, Vmax and Kcat with the measurement of initial velocity. As an example, these quantities were determined for pancreas protease with casein and N,N‐dimethylcasein as substrates. This study made clear the possibility of using a common substrate of proteolytic enzymes for kinetic studies and a general reference for activity expression. By introducing the use of initial velocity in the kinetic studies of proteolysis with protein as the substrate, this study also makes clear that the kinetics of the enzymatic proteolysis very well fits the Michaelis‐Menten law instead of the Schütz law.
An Infrared Investigation of Hydrogen Bonding of Methanol, Ethanol, 1‐Propanol, and 1‐Butanol in Solution
Authors: Liu Dahwei , Wang Chih‐Lueh , Chen Tunli 
Published: June 2015

AbstractThe aggregation phenomena of simple alcohols caused by hydrogen bonding in several organic solvents are studied by I. R. spectroscopy. The association constants of cyclic dimer of alcohols in CCI4 are evaluated, and the importance of solvent bascity effecting on the OH band frequency shift has been discussed.
Variation of Power Output with Changing Working Fluid in a Liquid‐Piston Two‐Phase Heat Engine
Authors: Pan Kee‐Chuan , Cheng Chung‐Heng 
Published: June 2015

AbstractEmphasis is placed upon selecting working fluid in the drinking bird heat engine. The power output is correlated with thermal efficiency, temperature gradient and heat transfer coefficient. Experimental results are illustrated by our theoretical approaches. We find that thermal efficiency will he largely improved if energy loss due to reheating is eliminated. Method of avoiding reheating and choice of connector height are also discussed. The selection of working fluid mainly depends upon temperature difference. Our theoretical development and experimental results are very useful in constructing a real engine.
Gamma Ray Induced Low Temperature in Situ Polymerization of Vinyl Chloride and Copolymfrization of Vinyl Chloride‐Vinyl Acetate in Taiwan‐Produced Woods
Authors: Wang Ung‐Ping 
Published: June 2015

AbstractGamma radiation induced polymerization of vinyl chloride (VC) and copolymerization of vinyl chloride (VC)‐vinyl acetate (VAc) in Taiwan cedars have been investigated at low temperatures. The polymerization‐rate of VC and the copolymerization‐rate of VC‐VAc system in wood were found to be proportional to the n powers of the dose‐rate, where n became close to the value of 1 as the polymerization temperature being lowered below 0°C. The oxygen in air was recognized to induce the delay of the induction period due to its retardation on the polymerization. The apparent activation energies of VC and VC‐VAc for the polymerization and the copolymerization in wood were determined by use of the Arrhenius plotting as 4.0 Kcal/mole and 3.4 Kcal/mole respectively at the temperature‐range of —15°C∼20°C. The degree of polymerization of VC was greatly affected by the polymerization temperature, although it was observed to be independent on the total gamma dose within 1 Mrad and the kinds of wood. No graft reaction of PVC polymer and PVC‐PVAc copolymer onto the wood cellulose was found, while low graft percentage of about 3% being obtained at 20° C in the case of using swelling agents. However, this value was found to be decreased to 0.1% at the temperature of —15°C. Based on the above‐mentioned experimental results, the radiation induced low temperature polymerization of VC or copolymerization of VC‐VAc system in Taiwan produced cedars are considered to proceed with radical polymerization mechanism.