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71.
72.
Aziz Sancar Neil D. Clarke Jonathan Griswold William J. Kennedy W.Dean Rupp 《Journal of molecular biology》1981,148(1):63-76
We have constructed plasmids carrying various restriction fragments of the biouvrB region of the Escherichia coli chromosome. By analyzing the proteins synthesized in maxicells from the uvrB+ plasmid pDR1494, and its derivatives containing γδ sequences inserted in the uvrB gene, we have determined that the uvrB gene is about two kilobase-pairs in length, that it is transcribed clockwise on the standard E. coli genetic map, and that it codes for a single polypeptide of Mr = 84,000. The number of uvrB polypeptides in a normal cell is estimated to be about 140.We have also found that the uvrB gene is cut by EcoRI near its promoter. 相似文献
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74.
Evidence is presented that cultured fetal rat hepatocytes, when incubated with a crude leucocytic extract derived from rabbits undergoing an inflammatory response, show a marked increase in fibrinogen production and a concomitant decrease in albumin production. Antibody binding to polyribosomes synthesizing fibrinogen and albumin shows the same inverse relationship in rats undergoing an artificially induced inflammatory response. These data demonstrate directly and unequivocally that during the acute phase (inflammatory) response, the biosynthesis of these two plasma proteins is inversely affected by a factor or factors acting directly on the liver. 相似文献
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Iñigo Garbayo Michal Struzik William J. Bowman Reto Pfenninger Evelyn Stilp Jennifer L. M. Rupp 《Liver Transplantation》2018,8(12)
Ceramic Li7La3Zr2O12 garnet materials are promising candidates for the electrolytes in solid state batteries due to their high conductivity and structural stability. In this paper, the existence of “polyamorphism” leading to various glass‐type phases for Li‐garnet structure besides the known crystalline ceramic ones is demonstrated. A maximum in Li‐conductivity exists depending on a frozen thermodynamic glass state, as exemplified for thin film processing, for which the local near range order and bonding unit arrangement differ. Through processing temperature change, the crystallization and evolution through various amorphous and biphasic amorphous/crystalline phase states can be followed for constant Li‐total concentration up to fully crystalline nanostructures. These findings reveal that glass‐type thin film Li‐garnet conductors exist for which polyamorphism can be used to tune the Li‐conductivity being potential new solid state electrolyte phases to avoid Li‐dendrite formation (no grain boundaries) for future microbatteries and large‐scale solid state batteries. 相似文献
77.
Jean‐Denis Pdelacq Beom‐Seop Rho Chang‐Yub Kim Geoffrey S. Waldo Timothy P. Lekin Brent W. Segelke Bernhard Rupp Li‐Wei Hung Su‐Il Kim Thomas C. Terwilliger 《Proteins》2006,62(3):563-569
The three‐dimensional structure of Rv2607, a putative pyridoxine 5′‐phosphate oxidase (PNPOx) from Mycobacterium tuberculosis, has been determined by X‐ray crystallography to 2.5 Å resolution. Rv2607 has a core domain similar to known PNPOx structures with a flavin mononucleotide (FMN) cofactor. Electron density for two FMN at the dimer interface is weak despite the bright yellow color of the protein solution and crystal. The shape and size of the putative binding pocket is markedly different from that of members of the PNPOx family, which may indicate some significant changes in the FMN binding mode of this protein relative to members of the family. Proteins 2006. © 2005 Wiley‐Liss, Inc. 相似文献
78.
Interactive controls of herbivory and fluvial dynamics on landscape vegetation patterns on the Tanana River floodplain, interior Alaska 总被引:2,自引:0,他引:2
Lem G. Butler † Knut Kielland T. Scott Rupp Thomas A. Hanley 《Journal of Biogeography》2007,34(9):1622-1631
Aim We examined the interactive effects of mammalian herbivory and fluvial dynamics on vegetation dynamics and composition along the Tanana River in interior Alaska.
Location Model parameters were obtained from field studies along the Tanana River, Alaska between Fairbanks (64°50.50' N, 147°43.30' W) and Manley Hot Springs (65°0.0' N, 150°36.0' W).
Methods We used a spatially explicit model of landscape dynamics (ALFRESCO) to simulate vegetation changes on a 1-year time-step. The model was run for 250 years and was replicated 100 times.
Results Increases in herbivory decreased the proportion of early successional vegetation and increased the proportion of late successional vegetation on the simulated landscape. Erosion and accretion worked as antagonists to herbivory, increasing the amount of early successional vegetation and decreasing the amount of late successional vegetation. However, the interactive effects of herbivory and erosion/accretion were especially important in determining system response, particularly in early seral vegetation types. High erosion rates, when coupled with low herbivory, greatly increased the proportion of willow on the landscape. When coupled with high herbivory, however, they greatly increased the proportion of alder on the landscape. At low levels of herbivory, alder abundance peaked at intermediate levels of erosion/accretion.
Main conclusions Neither erosion/accretion nor herbivory produced consistent landscape patterns that could be predicted independently of the other. These findings underscore the importance of the interactive effects of biotic and abiotic disturbances in shaping large-scale landscape vegetation patterns in boreal floodplain ecosystems – systems traditionally thought to be driven primarily by abiotic disturbance alone. 相似文献
Location Model parameters were obtained from field studies along the Tanana River, Alaska between Fairbanks (64°50.50' N, 147°43.30' W) and Manley Hot Springs (65°0.0' N, 150°36.0' W).
Methods We used a spatially explicit model of landscape dynamics (ALFRESCO) to simulate vegetation changes on a 1-year time-step. The model was run for 250 years and was replicated 100 times.
Results Increases in herbivory decreased the proportion of early successional vegetation and increased the proportion of late successional vegetation on the simulated landscape. Erosion and accretion worked as antagonists to herbivory, increasing the amount of early successional vegetation and decreasing the amount of late successional vegetation. However, the interactive effects of herbivory and erosion/accretion were especially important in determining system response, particularly in early seral vegetation types. High erosion rates, when coupled with low herbivory, greatly increased the proportion of willow on the landscape. When coupled with high herbivory, however, they greatly increased the proportion of alder on the landscape. At low levels of herbivory, alder abundance peaked at intermediate levels of erosion/accretion.
Main conclusions Neither erosion/accretion nor herbivory produced consistent landscape patterns that could be predicted independently of the other. These findings underscore the importance of the interactive effects of biotic and abiotic disturbances in shaping large-scale landscape vegetation patterns in boreal floodplain ecosystems – systems traditionally thought to be driven primarily by abiotic disturbance alone. 相似文献
79.
80.
Deoxyribonucleic Acid Transferred from Ultraviolet-Irradiated Excision-Defective Hfr Cells of Escherichia coli K-12 总被引:6,自引:3,他引:3 下载免费PDF全文
Deoxyribonucleic acid (DNA) transfer from (3)H-thymine-labeled Hfr cells has been measured by determining the amount of radioactivity remaining after selective lysis of the donor cells in the mating mixture. DNA transfer was less effectively reduced by ultraviolet irradiation of excision-defective Hfr cells than was the yield of recombinants. The buoyant density of DNA transferred from unirradiated and irradiated Hfr cells was equivalent to that of double-stranded DNA. Mating-dependent DNA synthesis in the recipient has been measured by mating Hfr cells deficient in thymidine kinase with irradiated thymine-requiring F(-) cells in the presence of (3)H-thymine. The extent of such DNA synthesis approximated the amount of DNA transferred from unirradiated donors. Neither DNA transfer nor mating-dependent DNA synthesis could be reliably measured when both parents were irradiated. It is proposed that transferred Hfr DNA is replicated in the recipient and that this replication still occurs when the Hfr DNA contains dimers. 相似文献