997 resultados para nutrient cycle
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.
Resumo:
Aim: 125I-iododeoxyuridine is a potential Auger radiation therapy agent. Its incorporation in DNA of proliferating cells is enhanced by fluorodeoxyuridine. Here, we evaluated therapeutic activities of 125I-iododeoxyuridine in an optimized fluorodeoxyuridine pre-treatment inducing S-phase synchronization. Methods: After S-phase synchronization by fluorodeoxyuridine, cells were treated with 125I-iododeoxyuridine. Apoptosis analysis and S-phase synchronization were studied by flow cytometry. Cell survival was determined by colony-forming assay. Based on measured growth parameters, the number of decays per cell that induced killing was extrapolated. Results: Treatment experiments showed that 72 to 91% of synchronized cells were killed after 0.8 and 8 kBq/ml 125I-iododeoxyuridine incubation, respectively. In controls, only 8 to 38% of cells were killed by corresponding 125I-iododeoxyuridine activities alone and even increasing the activity to 80 kBq/ml gave only 42 % killing. Duplicated treatment cycles or repeated fluorodeoxyuridine pre-treatment allowed enhancing cell killing to >95 % at 8 kBq/ml 125I-iododeoxyuridine. About 50 and 160 decays per S-phase cells in controls and S-phase synchronization, respectively, were responsible for the observed cell killing at 0.8 kBq/ml radio-iododeoxyuridine. Conclusion: These data show the successful application of fluorodeoxyuridine that provided increased 125I-iododeoxyuridine Auger radiation cell killing efficacy through S-phase synchronization and high DNA incorporation of radio-iododeoxyuridine.
Resumo:
Mouse mammary tumor virus (MMTV) infects the host via mucosal surfaces and exploits the host immune system for systemic spread and chronic infection. We have tested a neutralizing rat monoclonal antibody specific for the retroviral envelope glycoprotein gp52 for its efficiency in preventing acute and chronic mucosal and systemic infection. The antibody completely inhibits the superantigen response and chronic viral infection following systemic or nasal infection. Surprisingly however, the antibody only partially inhibits the early infection of antigen-presenting cells in the draining lymph node. Despite this initially inefficient protection from infection, superantigen-specific B- and T-cell responses and systemic viral spread are abolished, leading to complete clearance of the retroviral infection and hence interruption of the viral life cycle. In conclusion, systemic neutralizing monoclonal antibodies can provide an efficient protection against chronic retroviral amplification and persistence.
Resumo:
Background: Copeptin (CP), a derivate from the antidiuretic hormone (ADH) precursor pre-pro-vasopressin, stochiometrically mirrors ADH secretion. CP is increasingly evaluated as a diagnostic and prognostic biomarker in different diseases. It is therefore important to recognize possible confounding factors when interpreting CP levels. In healthy regularly menstruating women, there is a small but measurable physiological variability of hormones involved in fluid regulation. ADH plasma levels have been found to be lowest at menstruation, increasing during the follicular phase with a peak at ovulation and a drop in the luteal phase. We investigated the variability of CP during the menstrual cycle (MC) and its correlation to MC hormones. Methods: In total, 15 healthy women with regular MC (from 26 to 33 days) were included in this study. Ovulation was confirmed by progesterone (prog) levels on day 21 of the MC before entering the study and during the study. Blood collection was performed on days 3, 5, 8-16, 18, 21, 24 and 27 of their MC. Serums were assayed for prog, estradiol (E2), LH, and CP. Mixed linear regression analysis for repeated measures was performed to study the changes of CP, prog, E2 and LH during the MC, and to test the correlation of CP with sex hormones during the MC. Results: Mean MC length in all subjects was 28.5±2.2 d. E2, prog, and LH exhibited characteristic changes during the MC (all P< 0.05). All cycles were ovulatory (peak prog 54±15 nmol/l). CP levels did not change significantly throughout the MC, and were not associated with changes in prog, E2 or LH-levels (all P=ns). Conclusion: CP levels remain stable during the MC and are not influenced by changes in sex hormones. This implicates that it is not necessary to consider MC phases when using CP as a biomarker in premenopausal women.