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1.
Arash Masbough Kevin Frankowski Ken J. Hall Sheldon J.B. Duff 《Ecological Engineering》2005,25(5):552
Percolation of rainfall through woodwaste piles leaches natural chemicals from the wood residuals that can have adverse impacts on the environment. A study was conducted on a woodwaste storage site, adjacent to the Lower Fraser River, near Mission, BC, Canada. The objective of this research was to evaluate the effectiveness of constructed wetland for treatment of this woodwaste leachate. The leachate was characterized by high oxygen demand, tannin and lignin, and volatile fatty acids (VFAs), but low pH and nutrients. Diluted leachate passed through six pilot-scale wetland cells, four planted with cattail (Typha latifolia) and two unplanted controls, with a hydraulic retention time of 7 days and an average depth of 40 cm. Nutrient addition and pH adjustments were made to improve contaminant removal. Reductions in contaminants were consistently achieved, with average removals for BOD, COD, VFAs and tannin and lignin of 60, 50, 69 and 42%, respectively. Climatic conditions had an impact on the performance of the constructed wetland. Further operation of the system will help to elucidate the seasonal fluctuations. Aging of the constructed wetland system increased the treatment performance. 相似文献
2.
Z discs were isolated from Lethocerus flight muscle by removing the contractile proteins from myofibrils with a solution of high ionic strength. The protein composition of the Z discs was analysed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis; the major proteins were alpha-actinin, actin and tropomyosin. Z lines were selectively removed from intact myofibrils by digestion with crude lipase and chymotrypsin, but not by purified lipase. 相似文献
3.
Polymorphisms and deduced amino acid substitutions in the coding sequence of the ryanodine receptor (RYR1) gene in individuals with malignant hyperthermia. 总被引:13,自引:0,他引:13
E F Gillard K Otsu J Fujii C Duff S de Leon V K Khanna B A Britt R G Worton D H MacLennan 《Genomics》1992,13(4):1247-1254
Twenty-one polymorphic sequence variants of the RYR1 gene, including 13 restriction fragment length polymorphisms (RFLPs), were identified by sequence analysis of human ryanodine receptor (RYR1) cDNAs from three individuals predisposed to malignant hyperthermia (MH). All RFLPs were detectable in PCR-amplified products, and their segregation was consistent with our initial finding of linkage to MH in the nine families previously informative for one or more intragenic markers (MacLennan et al., 1990, Nature 343:559-561). Four amino acid substitutions were identified in the study: Arg for Gly248, Cys for Arg470, Leu for Pro1785, and Cys for Gly2059. Of 45 families tested, a single family presented the Arg for Gly248 substitution where it segregated with malignant hyperthermia, making it a candidate mutation for predisposition to MH in man. The other three polymorphic substitutions failed to segregate with malignant hyperthermia in those families in which they occurred, implying that they represent polymorphisms with little or no effect on the function of the RYR1 gene. 相似文献
4.
R A Mustard C Lipohar R J Finley J H Duff J Radziuk C Nohr 《Laboratory animal science》1986,36(4):393-395
Reliable short-term blood access in conscious swine was provided by implanting multiple silastic catheters. Catheters were inserted into the aorta, hepatic vein, portal vein, and inferior vena cava through a midline laparotomy incision. Multiple catheters also were placed into the external jugular vein through a separate cervical incision. Catheter patency rates for blood withdrawal on the sixth post-operative day were: arterial 100%, hepatic 91%, portal 86%, inferior vena cava 71%. No animal had major wound or catheter infection on the seventh post-operative day. The methods described allow metabolic studies, including measurements of splanchnic blood flow, to be carried out either acutely or for up to at least 7 days post-operatively. 相似文献
5.
R.Robert Schellenberg Marilyn J. Duff Aidan Foster Harry B. Paddon 《Prostaglandins & other lipid mediators》1986,32(2)
Histamine caused a triphasic response of human pulmonary artery strips in vitro, consisting of a small initial contraction followed by pronounced relaxation preceding a second contractile response. These characteristics were not seen with other contractile stimuli including 5-hdyroxytryptamine, leukotriene D4, and KC1. The relaxant component of this response was ablated by removal of endothelium from the vascular strips or by pretreatment of the tissues with 1μM indomethacin. Measurement of the PGI2 degradation product 6-keto-PGF1α in supernatants from histamine-challenged tissues confirmed the synthesis of PGI2. Supernatants from unstimulated or leukotriene-challenged tissues contained no detectable amounts of 6-keto-PGF1α. The histamine H1 antagonist diphenhydramine inhibited both the contractile and relaxant responses to histamine whereas the H2 antagonist cimetidine affected neither component. The released PGI2 significantly altered the dose-respons curve to histamine without inhibiting the maximal contractile responses. We conclude that histamine induces PGI2 formation from pulmonary arterial endothelium via an H1 receptor. 相似文献
6.
Branched-chain amino acid metabolism and alanine formation in rat muscles in vitro. Mitochondrial-cytosolic interrelationships. 总被引:2,自引:2,他引:0 下载免费PDF全文
Muscle branched-chain amino acid metabolism is coupled to alanine formation via branched-chain amino acid aminotransferase and alanine aminotransferase, but the subcellular distributions of these and other associated enzymes are uncertain. Recovery of branched-chain aminotransferase in the cytosol fraction after differential centrifugation was shown to be accompanied by leakage of mitochondrial-matrix marker enzymes. By using a differential fractional extraction procedure, most of the branched-chain aminotransferase activity in rat muscle was located in the mitochondrial compartment, whereas alanine aminotransferase was predominantly in the cytosolic compartment. Phosphoenolpyruvate carboxykinase, like aspartate aminotransferase, was approximately equally distributed between these subcellular compartments. This arrangement necessitates a transfer of branched-chain amino nitrogen and carbon from the mitochondria to the cytosol for alanine synthesis de novo to occur. In incubations of hemidiaphragms from 48 h-starved rats with 3mM-valine or 3mM-glutamate, the stimulation of alanine release was inhibited by 69% by 1 mM-aminomethoxybut-3-enoate, a selective inhibitor of aspartate aminotransferase. Leucine-stimulated alanine release was unaffected. These data implicate aspartate aminotransferase in the transfer of amino acid carbon and nitrogen from the mitochondria to the cytosol, and suggest that oxaloacetate, via phosphoenolpyruvate carboxykinase, can serve as an intermediate on the route of pyruvate formation for muscle alanine synthesis. 相似文献
7.
Properties of Hamster Embryo Fibroblasts Transformed In Vitro After Exposure to Ultraviolet-Irradiated Herpes Simplex Virus Type 2 总被引:53,自引:30,他引:23 下载免费PDF全文
An in vitro method which led to the transformation of hamster embryo fibroblasts after exposure to herpes simplex virus type 2 (HSV-2) inactivated with ultraviolet irradiation is described. The transformed cells (333-8-9) produced tumors when inoculated into newborn Syrian hamsters but not when injected into weanling Syrian hamsters of the same LSH inbred strain. However, after one in vivo passage, the 333-8-9 cells became highly oncogenic in weanling hamsters. No infectious virus was recovered from these cells. Herpes simplex virus antigens were detected in the transformed cells by the indirect immunofluorescence technique. Sera from tumor-bearing hamsters contained antibody with highly specific neutralizing activity against HSV-2. These studies indicate the continued involvement of the HSV-2 genome in an oncogenic cell line. 相似文献
8.
Enrolment in the 13 Canadian medical schools in 1966-67 reached a new high of 4230, an increase of 5.1% over 1965-66. The percentage of women among medical students (12.1%) was close to that of the preceding three years. There has been a levelling off in the decline of students from outside Canada in 1966-67, when 9.5% of medical students were non-Canadian. The decline had been primarily in the number of American students, which continues. The number of students from Commonwealth countries has shown a steady increase during the eight-year period under review; in 1966-67, they make up nearly one-half of all non-Canadian students. It was noted that 18.5% of overseas students came to Canada under governmental or intergovernmental sponsorship. Of the Canadian students, 94% came from the “home” provinces of the medical schools. 相似文献
9.
Response to Phosphate Deprivation in Brassica nigra Suspension Cells : Enhancement of Intracellular, Cell Surface, and Secreted Phosphatase Activities Compared to Increases in Pi-Absorption Rate 总被引:5,自引:3,他引:2 下载免费PDF全文
Suspension cells of Brassica nigra responded to Pi deprivation by increasing their potential for Pi influx and by raising the active levels of intracellular, cell surface, and secreted acid phosphatases. These responses, however, were temporally distinct. Phosphate influx capacity increased 15-fold in parallel to a 10-fold decrease in endogenous Pi during 7 days of culture in basal growth medium. In contrast, intracellular and cell surface phosphatase activities changed only after alterations in cellular phosphorus status had been in place for a number of days. Even in nutrient sufficient cells the secretion of phosphatase remained relatively high as did the activities of the other phosphatases. The cell surface acid phosphatase had a Km of approximately 10 times that of the influx process and molybdate was a much stronger inhibitor of this phosphatase activity. From these results it appears that Pi absorption and the production or activation of phosphatases are regulated in a distinct manner. In addition, Pi uptake into Brassica nigra cells does not appear to directly involve the cell surface phosphatase under Pi-deficient conditions. 相似文献
10.
Angiotensin II stimulates the pp44 and pp42 mitogen-activated protein kinases in cultured rat aortic smooth muscle cells. 总被引:5,自引:0,他引:5
J L Duff B C Berk M A Corson 《Biochemical and biophysical research communications》1992,188(1):257-264
Vasoconstrictors such as angiotensin II (ang II) stimulate vascular smooth muscle cell growth and share many signal transduction mechanisms with growth factors. Recently, growth factors have been shown to stimulate mitogen-activated protein (MAP) kinases, a family of serine/threonine protein kinases which phosphorylate pp90rsk, a cytosolic kinase that phosphorylates ribosomal S6 protein. We examined the effect of ang II on MAP kinase activity and phosphorylation. Ang II stimulated MAP kinase activity by 4-fold after 5 min exposure and also increased tyrosine phosphorylation of 42 kDa (74 +/- 41%) and 44 kDa (263 +/- 85%) proteins, shown to be pp42mapk and pp44mapk by Western blot analysis using a MAP kinase antibody. These results suggest that ang II-stimulated protein synthesis is mediated by a MAP kinase dependent pathway. 相似文献