1,144 research outputs found

    Homotransplantation of multiple visceral organs

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    It was technically possible to perform simultaneous homotransplantation of multiple visceral organs including the liver, spleen, pancreas, omentum and the entire gastrointestinal tract. Arterialization of the cooled graft was accomplished through the donor aorta which was removed with the graft and attached to that of the recipient dog. Gastrointestinal hemorrhage after surgery accounted for a high operative mortality and was thought to be due to denervation of the graft. The five dogs which survived the immediate trauma of surgery lived for five and a half to nine days. After the second day, these animals were physically active and able to resume oral alimentation. In three dogs, there was metabolic evidence of rejection of the liver. In two others, jaundice did not develop. These observations were compared with chemical, hematologic and pathologic data obtained in previous experiments involving homotransplantation of the liver alone. In some cases, there was less evidence of host versus graft rejection after the multiple organ transplants. Other data in the present study suggested the possibility that a significant graft versus host reaction may have been an important contributory cause of death. Β© 1962

    Effects of Substituents on the Length of Central C(sp^3)-C(sp^3) Bond in Anthracene Photodimers and Related Molecules

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    Effects of substituents on the lengths of the central C–C single bond in the butterfly-shaped anthracene photodimers (1)–(7) and lepidopterenes (8) are studied. X-Ray analysis of the photodimer (10) of 9,10-difluoroanthracene gave a C(9)–C(10β€²) bond length of 1.631 (3)Γ…. An attempt to re-determine molecular structure of the photoisomer (5) of [2.2](9,10) anthracenophane (12) by neutron diffraction analysis is also reported [C(9)–C(10β€²): obs. 1.64(1), calc. 1.63(1)Γ…]. The D_2 structure that had been proposed for the minimum-energy conformation of (5) is questioned and the D_(2h) symmetric conformation is suggested on the basis of the diffraction results and MNDO calculations. The experimentally determined distances of the long central C–C bonds in these butterfly compounds including dianthronyl (9) are well reproduced by MNDO calculations with a standard deviation of 0.013 Γ…. Small but significant further elongation of the central C–C bond by up to 0.07 Γ… resulting from annulation of cyclobutane or cyclopentane ring in anthracene photodimers and from remote chlorine substitution in lepidopterene are interpreted in terms of the increased Ο€β†’Οƒ^* orbital interaction

    Analysis of geologic terrain models for determination of optimum SAR sensor configuration and optimum information extraction for exploration of global non-renewable resources. Pilot study: Arkansas Remote Sensing Laboratory, part 1, part 2, and part 3

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    Computer-generated radar simulations and mathematical geologic terrain models were used to establish the optimum radar sensor operating parameters for geologic research. An initial set of mathematical geologic terrain models was created for three basic landforms and families of simulated radar images were prepared from these models for numerous interacting sensor, platform, and terrain variables. The tradeoffs between the various sensor parameters and the quantity and quality of the extractable geologic data were investigated as well as the development of automated techniques of digital SAR image analysis. Initial work on a texture analysis of SEASAT SAR imagery is reported. Computer-generated radar simulations are shown for combinations of two geologic models and three SAR angles of incidence

    The steering gaits of sperm

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    Sperm are highly specialized cells, which have been subject to substantial evolutionary pressure. Whereas some sperm features are highly conserved, others have undergone major modifications. Some of these variations are driven by adaptation to mating behaviours or fitness at the organismic level. Others represent alternative solutions to the same task. Sperm must find the egg for fertilization. During this task, sperm rely on long slender appendages termed flagella that serve as sensory antennas, propellers and steering rudders. The beat of the flagellum is periodic. The resulting travelling wave generates the necessary thrust for propulsion in the fluid. Recent studies reveal that, for steering, different species rely on different fundamental features of the beat wave. Here, we discuss some examples of unity and diversity across sperm from different species with a particular emphasis on the steering mechanisms. This article is part of the Theo Murphy meeting issue β€˜Unity and diversity of cilia in locomotion and transport’

    Investigation of Molecular Iridium Fluorides IrFn (n=1–6): A Combined Matrix-Isolation and Quantum-Chemical Study

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    The photo-initiated defluorination of iridium hexafluoride (IrF6) was investigated in neon and argon matrices at 6β€…K, and their photoproducts are characterized by IR and UV-vis spectroscopies as well as quantum-chemical calculations. The primary photoproducts obtained after irradiation with Ξ»=365β€…nm are iridium pentafluoride (IrF5) and iridium trifluoride (IrF3), while longer irradiation of the same matrix with Ξ»=278β€…nm produced iridium tetrafluoride (IrF4) and iridium difluoride (IrF2) by Irβˆ’F bond cleavage or F2 elimination. In addition, IrF5 can be reversed to IrF6 by adding a F atom when exposed to blue-light (Ξ»=470β€…nm) irradiation. Laser irradiation (Ξ»=266β€…nm) of IrF4 also generated IrF6, IrF5, IrF3 and IrF2. Alternatively, molecular binary iridium fluorides IrFn (n=1–6) were produced by co-deposition of laser-ablated iridium atoms with elemental fluorine in excess neon and argon matrices under cryogenic conditions. Computational studies up to scalar relativistic CCSD(T)/triple-ΞΆ level and two-component quasirelativistic DFT computations including spin-orbit coupling effects supported the formation of these products and provided detailed insights into their molecular structures by their characteristic Irβˆ’F stretching bands. Compared to the Jahn-Teller effect, the influence of spin-orbit coupling dominates in IrF5, leading to a triplet ground state with C4v symmetry, which was spectroscopically detected in solid argon and neon matrices

    ΠŸΡ€ΠΎΠ±Π»Π΅ΠΌΡ‹ Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΠΈ ΠΈ освоСния Π½Π΅Π΄Ρ€. Π’. 2

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    Π’ сборникС ΠΎΡ‚Ρ€Π°ΠΆΠ΅Π½Ρ‹ ΠΏΡ€ΠΎΠ±Π»Π΅ΠΌΡ‹ ΠΏΠ°Π»Π΅ΠΎΠ½Ρ‚ΠΎΠ»ΠΎΠ³ΠΈΠΈ, стратиграфии, Ρ‚Π΅ΠΊΡ‚ΠΎΠ½ΠΈΠΊΠΈ, историчСской ΠΈ Ρ€Π΅Π³ΠΈΠΎΠ½Π°Π»ΡŒΠ½ΠΎΠΉ Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΠΈ, ΠΌΠΈΠ½Π΅Ρ€Π°Π»ΠΎΠ³ΠΈΠΈ, Π³Π΅ΠΎΡ…ΠΈΠΌΠΈΠΈ, ΠΏΠ΅Ρ‚Ρ€ΠΎΠ»ΠΎΠ³ΠΈΠΈ, Π»ΠΈΡ‚ΠΎΠ»ΠΎΠ³ΠΈΠΈ, ΠΏΠΎΠ»Π΅Π·Π½Ρ‹Ρ… ископаСмых, ΠΌΠ΅Ρ‚Π°Π»Π»ΠΎΠ³Π΅Π½ΠΈΠΈ, Π³ΠΈΠ΄Ρ€ΠΎΠ³Π΅ΠΎΠ»ΠΎΠ³ΠΈΠΈ, Π³ΠΈΠ΄Ρ€ΠΎΠ³Π΅ΠΎΡ…ΠΈΠΌΠΈΠΈ, ΠΈΠ½ΠΆΠ΅Π½Π΅Ρ€Π½ΠΎΠΉ Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΠΈ, Π³Π΅ΠΎΡ„ΠΈΠ·ΠΈΠΊΠΈ, нСфтяной Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΠΈ, Π³Π΅ΠΎΠΈΠ½Ρ„ΠΎΡ€ΠΌΠ°Ρ†ΠΈΠΎΠ½Π½Ρ‹Ρ… систСм Π² Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΠΈ, Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚ΠΊΠΈ нСфтяных ΠΈ Π³Π°Π·ΠΎΠ²Ρ‹Ρ… мСстороТдСний, ΠΏΠ΅Ρ€Π΅Ρ€Π°Π±ΠΎΡ‚ΠΊΠΈ ΡƒΠ³Π»Π΅Π²ΠΎΠ΄ΠΎΡ€ΠΎΠ΄Π½ΠΎΠ³ΠΎ ΠΈ ΠΌΠΈΠ½Π΅Ρ€Π°Π»ΡŒΠ½ΠΎΠ³ΠΎ ΡΡ‹Ρ€ΡŒΡ, нСфтСгазопромыслового оборудования, бурСния нСфтяных ΠΈ Π³Π°Π·ΠΎΠ²Ρ‹Ρ… скваТин, Ρ‚Π΅Ρ…Π½ΠΈΠΊΠΈ ΠΈ Ρ‚Π΅Ρ…Π½ΠΎΠ»ΠΎΠ³ΠΈΠΈ Ρ€Π°Π·Π²Π΅Π΄ΠΊΠΈ ΠΈ Π΄ΠΎΠ±Ρ‹Ρ‡ΠΈ, транспорта ΠΈ хранСния Π½Π΅Ρ„Ρ‚ΠΈ ΠΈ Π³Π°Π·Π°, Π³ΠΎΡ€Π½ΠΎΠ³ΠΎ Π΄Π΅Π»Π°, Ρ‚Π΅Ρ…Π½ΠΎΠ»ΠΎΠ³ΠΈΠΈ ΠΈ Ρ‚Π΅Ρ…Π½ΠΈΠΊΠΈ Ρ€Π°Π·Π²Π΅Π΄ΠΊΠΈ мСстороТдСний ΠΏΠΎΠ»Π΅Π·Π½Ρ‹Ρ… ископаСмых, гСоэкологии, гидрогСоэкологии, ΠΎΡ…Ρ€Π°Π½Ρ‹ ΠΈ ΠΈΠ½ΠΆΠ΅Π½Π΅Ρ€Π½ΠΎΠΉ Π·Π°Ρ‰ΠΈΡ‚Ρ‹ ΠΎΠΊΡ€ΡƒΠΆΠ°ΡŽΡ‰Π΅ΠΉ срСды, комплСксного использования ΠΌΠΈΠ½Π΅Ρ€Π°Π»ΡŒΠ½ΠΎΠ³ΠΎ ΡΡ‹Ρ€ΡŒΡ, зСмлСустройства, экономики ΠΌΠΈΠ½Π΅Ρ€Π°Π»ΡŒΠ½ΠΎΠ³ΠΎ ΡΡ‹Ρ€ΡŒΡ ΠΈ Π³ΠΎΡ€Π½ΠΎΠ³ΠΎ ΠΏΡ€Π°Π²Π°

    Das Projekt "Mars One"

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