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DI-TERTIABYBUTYLNITROXIDE, A HILL REAGENT

Description: Di-tertiarybutylnitroxide (DTBN), which they have tried to use as a trapping agent to identify the species giving rise to the photo-induced EPR signals in photosynthetic materials, functions as a Hill reagent with spinach chloroplasts. Evidence is presented which indicates that the reduction of DTBN is affected by photosystem II of the electron transport system of spinach chloroplasts. The reduced form of DTBN, the hydroxylamine, undergoes a photo-oxidation with spinach chloroplasts. Possible e… more
Date: January 1, 1970
Creator: Corker, Gerald A.; Klein, Melvin P.; La Font, Didier & Calvin,Melvin.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ABSOLUTE ASYMMETRIC SYNTHESIS. I. ON THE MECHANISM OF THEPHOTOCHEMICAL ABSOLUTE ASYMMETRIC SYNTHESIS OF HELICENES WITH CIRCULARLYPOLARIZED LIGHT. . WAVELENGTH DEPENDENCE OF THE OPTICAL YIELD OFOCTAHELICENE.

Description: The synthesis of nonracemic yields of hexa-, hepta-, octa-, and nonhelicene with circular light was observed, and the structural and wavelength dependence of the induced optical yields was examined. The results obtained, together with a detailed consideration of the mechanism of helicene synthesis from the parent diarylolefins, indicate that the induced optical activity is due to selective reaction of enantiomeric conformations of the parent cis diarylolefins by circular light.
Date: May 1, 1971
Creator: Bernstein, William J.; Calvin, Melvin & Buchardt, Ole.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Communication: From Molecules to Mars

Description: An analysis is made of the energetic, molecular, macromolecular and organizational steps which appear to be essential for the development of a living cell from a nonliving origin. Accepting the current view of the primitive atmosphere of the earth, experimental demonstration for the formation of the fundamental molecules of living organisms (amino acids, fatty acids, purines and pyrimidines) under the influence of available energy sources (ultraviolet light, ionizing radiation and electric disc… more
Date: August 1, 1962
Creator: Calvin, Melvin
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ELECTROCHEMISTRY OF EXCITED MOLECULES: PHOTO-ELECTROCHEMICALREACTIONS OF CHLOROPHYLLS. I

Description: Semiconductors with a sufficiently large energy gap, in contact with an electrolyte, can be used as electrodes for the study of electrochemical reactions of excited molecules. The behavior of excited chlorophyll molecules at single crystal ZnO-electrodes has been investigated. These molecules inject electrons from excited levels into the conduction band of the electrode, thus giving rise to an anodic photocurrent. The influence of various agents on this electron transfer has been studied. In th… more
Date: December 1, 1970
Creator: Tributsch, Helmut & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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THE PHOTOCHEMISTRY OF PYRIDINE N-OXIDE

Description: The authors wish to report their results on the photolysis of pyridine N-oxide in alcoholic solution. Both methanol and ethanol solutions of pyridine N-oxide were irradiated. The reaction mixture was analyzed by gas-liquid chromatography (GLC) using a 2.5% FFAP on Chrom G column and a Porapak Q column. In order to collect the products, the volume of the photolysis solution was reduced in vacuo and the resulting mixture was separated by preparative GLC.
Date: September 14, 1967
Creator: Alkaitis, Algis & Calvin, Melvin.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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EXTRATERRESTRIAL LIFE: SOME ORGANIC CONSTITUENTS OF METEORITES ANDTHEIR SIGNIFICANCE FOR POSSIBLE EXTRATERRESTRIAL BIOLOGICALEVOLUTION

Description: In order to decide the value and type of information to be obtained from outer space with regard to its pertinence for the evolution of life, a brief review is presented of the current status of our thinking on the origin of life on earth. This points up the particular kinds of chemicals whose presence, or absence, on other astral bodies might be significant. Heretofore, the only data available are the result of telescopic spectroscopy. We report here information indicating the presence in mete… more
Date: December 7, 1959
Creator: Calvin, Melvin & Vaughn, Susan K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ENERGY RECEPTION AND TRANSFER IN PHOTOSYNTHESIS

Description: The basic information about the path of carbon in photosynthesis is reviewed together with the methods that were used to discover it. This has led to the knowledge of what is required of the photochemical reaction in the form of chemical species. Attention is then directed to the structure of the photochemical apparatus itself insofar as it is viewable by electron microscopy, and some principoles of ordered structure are devised for the types of molecules to be found in the chloroplasts. From t… more
Date: September 23, 1958
Creator: Calvin, Melvin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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SPECIFIC PROTONATION OF THE CARCINOGEN 7, 12-DIMETHYIBENZ [a]ANTHRACENE AND CHARGE LOCALIZATION IN THE a-COMPLEX

Description: In the class of the polycondensed aromatic hydrocarbons, the concept of localized charge in a {sigma}-complex, e.g., the carbonium ion formed by addition of a proton or other electrophile to an aromatic ring, has so far received experimental evidence only in the case of anthracene. The ultraviolet spectrum of this compound in sulfuric acid is similar to that of the benzhydryl cation. Ph{sub c}C{sup +}Me. This result implies the protonation of anthracene at one meso-carbon atom and the localizat… more
Date: April 1, 1971
Creator: Cavalieri, Ercole & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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FURTHERSTUDIES ON STERILITY PRODUCED IN MALE MICE BY DEUTERIUMOXIDE

Description: The authors have previously reported that deuterium oxide in the drinking water of either male or female mice produces sterility. An investigation of some of the conditions--with particular reference to time--of deuterium oxide treatment to produce sterile C{sub 57} male mice indicated that the sensitive phase of sperm production centered around the late prophase of meiosis. In some experiments, although D{sub 2}O was almost completely absent during maturation of the sperm, and when the mice ma… more
Date: June 1, 1960
Creator: Hughes, Ann M.; Bennett, Edward L. & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ELECTRICAL PROPERTIES OF ORGANIC SOLIDS. I. KINETICS AND MECHANISMOF CONDUCTIVITY OF METAL-FREE PHTHALOCYANINE

Description: Techniques involving the use of high-intensity short-duration light pulses have been applied t o the study of the kinetics of photoconductivity in films of metal-free phthalocyanine. These experiments, in conjunction with measurements of steady-state photoconductivity, are consistent with the following scheme. The principal route for the formation of charge carriers is via the first excited singlet state, although the lowest triplet state can, t o some extent, contribute to charge - carrier pro… more
Date: July 29, 1959
Creator: Tollin, Gordon; Kearns, David R. & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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KINETICS OF THE HYDROLYSIS AND ALCOHOLYSIS OF TETRAPOLYPHOSPHATEESTERS ('ETHYLMETAPHOSPHATE')

Description: 'Ethyl metaphosphate' or tetrapolyphosphate esters are a potentially useful starting material for the preparation of polynucleotides. The kinetics of the reactions of the esters with excess water and ethanol have been measured by means of p{sup 31} n.m.r. and IR spectroscopy. Upon the addition of specific amounts of water or ethanol, substances could be prepared which consist mainly of linear tetrapoly-, tripoly- or pyrophosphate esters containing smeller amounts of other polyphosphates and ort… more
Date: March 1, 1965
Creator: Burkhardt, Gottfried; Klein, Melvin P. & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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PREFERENTIAL INHIBITION OF THE GROWTH OF VIRUS-TRANSFORMED CELLS IN CULTURE BY RIFAZONE-82, A NEW RIFAMYCIN DERIVATIVE

Description: Rifazone-8{sub 2} (R-8{sub 2}), a new rifamycin derivative, is shown to preferentially inhibit the growth of virus-transformed chick cells in culture. Macromolecular synthesis and glucose uptake of transformed cells are also appreciably decreased in the presence of low concentrations of R-8{sub 2} where the normal cells appear unaffected. While R-8{sub 2} is shown to be a selective inhibitor of RNA-directed DNA polymerase in vitro, its action on the growth of transformed cells may involve some … more
Date: March 28, 1974
Creator: Bissell, Mina J.; Hatie, Carroll; Tischler, Allan N. & Calvin, Melvin.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ABIOGENIC INFORMATION COUPLING BETWEEN NUCLEIC ACID AND PROTEIN,OR, HOW PROTEIN AND DNA WERE MARRIED

Description: There is now experimental evidence for selectivity between the amino acid and the nucleic acid base which is the beginning of the chemical translation process from one linear system to the other. The linear system of the nucleic acid is, of course, an excellent place to store the information, whereas the linear system of the polypeptide, on the other hand, is the versatile system which can perform many different types of reactions but is unable to store information reliably. The experiments the… more
Date: December 1, 1968
Creator: Calvin, Melvin
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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OXYGEN 18 EXCHANGE REACTIONS OF ALDEHYDES AND KETONES

Description: Using infra-red spectroscopy, the equilibrium exchange times have been determined for a series of ketones, aromatic aldehydes, and {beta}-ketoesters reacting with oxygen 18 enriched water. These exchange times have been evaluated in terms of steric and electronic considerations, and applied to a discussion of the exchange times of chlorophylls a and b and chlorophyll derivatives.
Date: December 1, 1965
Creator: Byrn, Marianne & Calvin, Melvin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Phosphorus Turnover and Photosynthesis

Description: The participation of phosphorus in biological oxidation-reduction reactions of the type found in glycolysis ADP + PO{sub 4}H{sup -} + 3-phosphoglyceraldehyde + DPN{sup +} = 3-phosphoglycerate{sup -} + 2H{sup +} + DPNH + ATP has suggested theories in which similar reactions are proposed for photosynthesis. In these theories the reducing power of photosynthesis is utilized not only for reduction of carbon dioxide but also, by means of coupled oxidations, for the generation of high-energy phosphat… more
Date: November 1, 1947
Creator: Aronoff, Sam & Calvin, Melvin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ELECTRON-SPIN-RESONANCE STUDIES ON PHOTO-SYNTHETIC MATERIALS

Description: A number of organisms have been examined for their ability to produce electron-spin-resonance signals at low temperatures in response to illumination. The efficiency of the response is of the order of not less than 5%, and the wavelength for maximum response is generally slightly on the longer side of the wavelength of maximum absorption, with a minimum appearing at the wavelength of maximum absorption.
Date: May 11, 1960
Creator: Sogo, Power B.; Carter, Louise A. & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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PHOTOCHEMICAL COUPLING OF BENZO [a]PYRENE WITH 1-METHYL-CYTOSINE;PHOTO-ENHANCEMENT OF CARCINOGENICITY

Description: Irradiation of the carcinogenic benzo[a]pyrene (I) with 1-methylcytosine hydrochloride IIa (molar ratio 1:10) at 3500 {angstrom} in methanol-acetone produces the 6-(1-methylcytos-5-yl)-benzo[a]pyrene (III). The structure of the product shows the hydrocarbon bound through the most active 6-carbon atom to the nucleophilic 5-position of the base. In the second part, the possibility of observing carcinogenic effects on the mouse skin from non-carcinogenic hydrocarbons under the action of UV light i… more
Date: January 1, 1971
Creator: Cavalieri, E. & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ROUND TRIP FROM SPACE

Description: Whence came life on the surface of the earth? Whether or not a complete answer to this question may be found within the context, and content, of modern science, may be a moot question. It is our purpose to see how far we can devise an answer, and how satisfactory it may be, within that context. We trace a path from the primitive molecules of the primeval earth's atmosphere condensed from space through the random formation of more or less complex organic molecules, using the available energy sou… more
Date: October 29, 1958
Creator: Calvin, Melvin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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BRANCHED ALKANES FROM BLUE-GREEN ALGAE

Description: Branched alkanes from blue-green algae were separated on a 750 feet high resolution capillary gas chromatographic column. The mixture was found to be 90% of 1:1 ratio 7-methyl, and 8-methyl-heptadecane, and 10% of 6-methylheptadecane. An optical rotation of +2.5 {+-} 0.5 was obtained on a 5 mg of mixture.
Date: August 1, 1970
Creator: Han, Jerry & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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QUANTUM CONVERSION IN PHOTOSYNTHESIS

Description: A new suggestion is made based on model work associated with similar measurements on the biological material itself. The primary quantum conversion act is an ionization occurring in a charge transfer complex. This is what it amounts to in chemical terms. But this process cannot occur in isolated charge transfer molecules in solution because the products cannot escape from each other. The primary quantum conversion as it occurs in modern photosynthesis can only take place in a laminated structur… more
Date: January 1, 1961
Creator: Calvin, Melvin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Mechanism Op Action Op P-Hydroxybenzoate Hybrozylase Frompseudomonas Putida. Iii. The Enzyme-Subtrate Complex

Description: The mechanism of action of p-hydroxybenzoate hydroxylase from Pseudomonas putida, strain M-6, has been investigated. The aromatic substrate analogues, benzoate, p-fluorobenzoate, p-chlorobenzoate, p-nitrobenzoate, p-aminobenzoate, and 6-hydroxynicotinate, are found to be competitive inhibitors. This finding differs from the previously reported noncompetitive behavior in a different buffer system. The optical activity of the enzyme-inhibitor complex is studied. From the kinetic and circular dich… more
Date: April 1, 1971
Creator: Teng, Nelson N. H.; Kbtovycz, George; Calvin, Melvin & Hosokawa, Keiichi
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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THE IMPURITY OF SCIENCE

Description: Science is impure in two ways. There is not a 'pure' science. By this I mean that physics impinges on astronomy, on the one hand, and chemistry on biology on the other. And not only does each support its neighbors but derives sustenance from them. The same can be said of chemistry. Biology is, perhaps, the example par excellence today of an 'impure' science. Beyond this, there is no 'pure' science itself divorced from human values. The importance of science to the humanities and the humanities … more
Date: April 19, 1962
Creator: Calvin, Melvin
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ABSORPTION CHANGES IN BACTERIAL CHROMATOPHORES. II. A NEWCHLOROPHYLL-LIKE PIGMENT FROM THE OXIDATION OF CHROMATOPHORES FROMRHODOSPIRILLUM RUBRUM

Description: Evidence is presented which points to (at least) two bound forms of bacteriochlorophyll present in chromatophores of Rhodospirillum rubrum, both of them readily converted to unbound bacteriochlorophyll (abs. max. 770 mu) when the chromatophores are extracted with acetone or ethanol. Controlled oxidation of the chromatophores with Ir(IV) or with Zn(II) and ferricyanide preferentially destroys the more strongly absorbing pigment (abs. max. 880 mu) but brings about only a slight decrease in the ma… more
Date: October 1, 1964
Creator: Gould, Edwin S.; Kuntz Jr., Irwin D. & Calvin, Melvin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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