Aquatic chemistry: chemical processes in lakes     

Brezonik PL 《Science (New York, N.Y.)》1986,231(4742):1202-1203

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Carcinogen in rock fern (Chielanthes sieberi) from New Zealand and Australia     

BL SMITH  PP EMBLING  DR LAUREN  MP AGNEW  AD ROSS  PL GREENTREE 《Australian veterinary journal》1989,66(7):230-231

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Reduction and recovery of N-acetylglucosamine-1-phosphate transferase activity in the liver of sheep and rats after a single subcutaneous dose of tunicamycin     

PL STEWART  C MAY CSIRO  MV JAGO 《Australian veterinary journal》1998,76(4):287-288

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BSE: lessons for Australia     

PL YOUNG 《Australian veterinary journal》1996,74(2):126-127

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Sediment acid neutralization in softwater lakes     

L. A. Baker  P. L. Brezonik  E. S. Edgerton  R. W. Ogburn III 《Water, air, and soil pollution》1985,25(2):215-230

Acid neutralizing capacities (ANC) of sediments from McCloud Lake, Florida and seven other lakes in Wisconsin and Florida were as high as 10 meq 100 g^?1 over the pH range 4.5 to 5.5 in well-mixed batch experiments. Exchange of Ca²⁺ and Mg²⁺ accounted for over 50% of the neutralizing capacity; Al solubilization and sulfate adsorption were unimportant in neutralizing H⁺ additions. ANC was correlated with sediment volatile solids content. Sulfate reduction occurred in microcosms that simulated lake-water interactions and subsurface seepage;in situ pore water profiles and a whole-lake mass balance confirm the occurrence of this process in McCloud Lake. Sediment neutralization is important for lakes that receive most of their water from precipitation and thus are particularly susceptible to acidification.  相似文献   

Acetylene reduction activity associated with tree roots in cypress wetlands     

Forrest E. Dierberg  Patrick L. Brezonik 《Soil biology & biochemistry》1981,13(6):555-557

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Empirical models for lake acidification in the upper Great Lakes Region     

J. A. Rogalla  P. L. Brezonik  G. E. Glass 《Water, air, and soil pollution》1986,31(1-2):95-100

A large data base on inland lakes in the Upper Great Lakes Region (UGLR) was used to evaluate assumptions and relationships of empirical acidification models. Improved methods to calculate background alkalinity and background SO₄ ^2? are reported; SO₄ ^2? enrichment factors indicate that terrestrial SO₄ ^2? sources and watershed or lake sinks must be considered for site-specific background SO₄ ^2? estimates. Significant relationships were found between lake acidification estimated as change in SO₄ ^2? and precipitation acidity but not between changes in lake alkalinity and precipitation acidity in this lightly impacted region.  相似文献   

Experimental acidification of Little Rock Lake,Wisconsin     

P. L. Brezonik  L. A. Baker  J. R. Eaton  T. M. Frost  P. Garrison  T. K. Kratz  J. J. Magnuson  W. J. Rose  B. K. Shephard  W. A. Swenson  C. J. Watras  K. E. Webster 《Water, air, and soil pollution》1986,31(1-2):115-121

The controlled acidification of a two-basin lake is described. The lake was divided by a vinyl curtain in 1984; acidification of one basin began in 1985. Target pH values of 5.5, 5.0 and 4.5 are planned for 2-yr increments. Biotic and chemical responses and internal alkalinity generation are being studied. Baseline studies, initial results at pH 5.5, and predictions of lake responses to acidification are described.  相似文献   

Pharmacokinetic and pharmacodynamic modelling of intravenous,intramuscular and subcutaneous buprenorphine in conscious cats     

Paulo VM Steagall  Ludovic Pelligand  Tatiana Giordano  Christophe Auberger  John W Sear  Stelio PL Luna  Polly M Taylor 《Veterinary anaesthesia and analgesia》2013,40(1):83-95

ObjectiveTo describe simultaneous pharmacokinetics (PK) and thermal antinociception after intravenous (IV), intramuscular (IM) and subcutaneous (SC) buprenorphine in cats.Study designRandomized, prospective, blinded, three period crossover experiment.AnimalsSix healthy adult cats weighing 4.1 ± 0.5 kg.MethodsBuprenorphine (0.02 mg kg^?1) was administered IV, IM or SC. Thermal threshold (TT) testing and blood collection were conducted simultaneously at baseline and at predetermined time points up to 24 hours after administration. Buprenorphine plasma concentrations were determined by liquid chromatography tandem mass spectrometry. TT was analyzed using anova (p < 0.05). A pharmacokinetic-pharmacodynamic (PK-PD) model of the IV data was described using a model combining biophase equilibration and receptor association-dissociation kinetics.ResultsTT increased above baseline from 15 to 480 minutes and at 30 and 60 minutes after IV and IM administration, respectively (p < 0.05). Maximum increase in TT (mean ± SD) was 9.3 ± 4.9 °C at 60 minutes (IV), 4.6 ± 2.8 °C at 45 minutes (IM) and 1.9 ± 1.9 °C at 60 minutes (SC). TT was significantly higher at 15, 60, 120 and 180 minutes, and at 15, 30, 45, 60 and 120 minutes after IV administration compared to IM and SC, respectively. IV and IM buprenorphine concentration-time data decreased curvilinearly. SC PK could not be modeled due to erratic absorption and disposition. IV buprenorphine disposition was similar to published data. The PK-PD model showed an onset delay mainly attributable to slow biophase equilibration (t_1/2k_e0 = 47.4 minutes) and receptor binding (k_on = 0.011 mL ng^?1 minute^?1). Persistence of thermal antinociception was due to slow receptor dissociation (t_1/2k_off = 18.2 minutes).Conclusions and clinical relevanceIV and IM data followed classical disposition and elimination in most cats. Plasma concentrations after IV administration were associated with antinociceptive effect in a PK-PD model including negative hysteresis. At the doses administered, the IV route should be preferred over the IM and SC routes when buprenorphine is administered to cats.  相似文献   

Prevalence,radiographic resolution and outcomes of slab fractures of the third and central tarsal bones in juvenile Thoroughbred horses     

CM Steel  VL Collins  SR Hance  AR Adkins  PL Hitchens 《Australian veterinary journal》2019,97(4):108-115

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