An Unusual Necrotizing cholangiohepatitis in Broiler Chickens          下载免费PDF全文

Shapiro JL  Julian RJ  Hampson RJ  Trenton RG  Yo IH 《The Canadian veterinary journal. La revue veterinaire canadienne》1988,29(8):636-639

A diagnosis of toxic necrotizing cholangiohepatitis was made in approximately 35% of a flock of 23,000 commercial broiler chickens. Affected chickens were small, and had discrete green foci throughout the liver. Seven to twelve days prior to shipping the flock to slaughter, premixes containing oxytetracycline, monensin, and 3-nitro-4-hydroxyphenylarsonic acid had been added to the ration because the birds had wet droppings and were growing slowly. The 3-nitro-4-hydroxyphenylarsonic acid had been inadvertently incorporated at ten times the recommended level. Liver and kidney of affected birds had elevated levels of total arsenic, and special strains demonstrated arsenic in necrotic foci in liver. Histologically there was marked dilation of intrahepatic bile ducts, and patchy necrosis and hyperplasia of the bile duct epithelium. Damage to bile ducts may have been a toxic manifestation of altered metabolism and excretion of the three drugs being fed to birds suffering from intercurrent diarrhea and/or undefined interactions among the drugs.  相似文献   

Was there a prelude to the dinosaurs' demise?     

Kerr RA 《Science (New York, N.Y.)》1988,239(4841):729-730

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Du Pont Stakes Claim on Superconductor Rights: A fight looms over patent rights to the first high-temperature superconductor, as several companies hope to develop the material     

Pool R 《Science (New York, N.Y.)》1988,241(4870):1156

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Laser-Cooled Atoms Hit Record Low Temperatures: Carefully tuned lasers now chill atoms to a few millionths of a degree, allowing precise measurements of atomic properties     

Pool R 《Science (New York, N.Y.)》1988,241(4869):1041-1042

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Science and technology awards     

Trivelpiece AW 《Science (New York, N.Y.)》1988,241(4869):1025

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New Superconductors Come Through: High-temperature superconductors have proved difficult to put to practical use, but recent advances in thallium-and bismuth-based materials should bring applications closer to reality     

Pool R 《Science (New York, N.Y.)》1988,240(4859):1613-1615

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Comet Source: Close to Neptune: A computer simulation of orbital dynamics points to a close-in source for some comets; the source may even be observable, and astronomers are already beginning a search for it     

Kerr RA 《Science (New York, N.Y.)》1988,239(4846):1372-1373

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Parallel supercomputers for lattice gauge theory     

Brown FR  Christ NH 《Science (New York, N.Y.)》1988,239(4846):1393-1400

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Membrane Protein Holds Photosynthetic Secrets: This year's Nobel Prize for chemistry recognizes the direct and indirect benefits that flowed from the crystallization of the photosynthetic reaction center from a bacterial membrane     

Lewin R 《Science (New York, N.Y.)》1988,242(4879):672-673

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Thermodynamic efficiency of brittle frictional mountain building     

Barr TD  Dahlen FA 《Science (New York, N.Y.)》1988,242(4879):749-752

An active fold-and-thrust belt in unchanging tectonic and climatic conditions attains a dynamic steady-state in which the influx of accreted material at the toe is balanced by the erosive efflux off the top. The overall balance of energy in such a steady-state fold-and-thrust belt is described by the equation E = W(G) + Q, where E is the rate at which both mechanical and heat energy are added from external sources, W(G) is the rate of work performed against gravitational body forces, and Q is the rate at which waste heat flows out of the upper and lower boundaries. The total amount of power being supplied to the active Taiwan fold-and-thrust belt by the subducting Eurasian plate and in situ radioactivity is 4.2 gigawatts. Because only 0.5 gigawatts are expended in doing useful work against gravity and the remaining 3.7 gigawatts are ejected as heat, the efficiency of brittle frictional mountain building in Taiwan is 11 percent.  相似文献