The level of bound malathion residues in treated wheat grain and its toxic effects on rats were investigated. Wheat grain was treated with [14C] malathion (specific activity: 2.76 MBq/mg) to determine the bioavailabil...The level of bound malathion residues in treated wheat grain and its toxic effects on rats were investigated. Wheat grain was treated with [14C] malathion (specific activity: 2.76 MBq/mg) to determine the bioavailability of bound residues in rats. At the same time, grain was treated with nonlabeled malathion to test for possible toxic effects of bound residues in a subchronic (90 days) feeding study in rats at two dose levels. 10 and 100 ppm.It was observed that the level of malathion-bound residues amounted to 11.28% of the applied dose (for six months). Also, it was noted that the main route of [14C]-malathion excretion was through the urine. This signifies that grain-bound malathion was bioavailable. In subchronic test on rats bound malathion residues (both dose levels) induced effects to some extent in organ weight (spleen and adrenals), and blood ChE activity. In both, males and females, there was an increase in SGPT activity (lower dose), and in alkaline phosphatase in females (higher dose). Hematological data showed changes only in hemoglobin concentration in males (both dose levels).展开更多
This study analyzes the level of total and bound pirimiphos-methyl residues in treated wheat grain and its toxic effects on rats.Wheat grain was treated with[(14)~C]pirimiphos-methyl of 16.36 mCi/mmol specific activit...This study analyzes the level of total and bound pirimiphos-methyl residues in treated wheat grain and its toxic effects on rats.Wheat grain was treated with[(14)~C]pirimiphos-methyl of 16.36 mCi/mmol specific activity to determine the bioavailability of bound residues in rats.At the same time,grain was treated with nonlabeled pirimiphos-methyl as required to determine any possible toxic effects of bound residues in a subacute feeding study in rats.Two dose levels were used:10 and 100 ppm(the former being the recommended dose level in practical treatment). Estimation of the type of residues was performed at intervals of 0,30,90,120,150,and 180 days.During and after the animal feeding study,changes in body weight gain,organ weight, cholinesterase activity,serum enzyme activity,and hematology were investigated.There is an indication that bound residues of the pesticide pirimiphos-methyl provoke toxic effects to some extent.1989 Academic Press.Inc.展开更多
This work proposes a 12 kW three-phase grid-connected single stage PWM DC-AC converter destined to process the energy provided by a photovoltaic array composed of 57 KC200GT PV modules with high power factor for any s...This work proposes a 12 kW three-phase grid-connected single stage PWM DC-AC converter destined to process the energy provided by a photovoltaic array composed of 57 KC200GT PV modules with high power factor for any solar radiation. The PWM inverter modeling and the control strategy, using dqO transformation, are proposed in order to also allow the system operation as an active power filter, capable to compensate harmonic components and react power generated by the non-linear loads connected to the mains grid. An input voltage clamping technique is proposed to impose the photovoltaic operation on the maximum power point. Simulation and experimental results are presented to validate the proposed methodology for grid connected photovoltaic generation system.展开更多
This work presents the design and control of the DAB （dual active bridge） converter employing gyrator＇s theory. A brief summary of the theory is introduced, and its application for the DAB converter is verified wit...This work presents the design and control of the DAB （dual active bridge） converter employing gyrator＇s theory. A brief summary of the theory is introduced, and its application for the DAB converter is verified with a design example. After that, it develops the control and show results of simulations and experiment. Though the commutation not is studied, the advantage of method is the easy way for project and control of the DAB converter.展开更多
The sub-Saharan region holds a wide variety of indigenous plant species, still offering the possibility to discover very interesting new natural products with potential therapeutic value. Most of the African populatio...The sub-Saharan region holds a wide variety of indigenous plant species, still offering the possibility to discover very interesting new natural products with potential therapeutic value. Most of the African population depends on traditional medicine for primary health care, however, neurological disorders are often not considered as common diseases and many people with mental illnesses, like epilepsy, are severely affected by health-related stigma and discrimination. Epilepsy is the most common serious chronic brain disorder, estimated to affect at least 10 million people in Africa. Guinea-Bissau is located in West Africa, and its population is mainly rural with very few health services available. Since the earliest times, Guinea-Bissau flora has constituted the main source of materials used in folk medicine and the local population, who is well versed in the uses of these plants and their properties. The aim of this study was to document the existing knowledge and practices related to the treatment of neurological disorders, namely epilepsy and seizures, in Guinea-Bissau and in other West African countries. The results presented from this study provide information not only on the specific plants used to treat neurological disorders, but also on social knowledge brought in by various ethnic groups, each one having its own culture, beliefs and ways of nature appropriation. Taking into account the existing knowledge on the medicinal properties of plants for treatment of neurologic disorders, it is believed that research in the areas of ethnomedicine and ethnopharmacology in Guinea-Bissau can bring promising results capable of adding value to the very rich natural resources of this country of West Africa.展开更多
文摘The level of bound malathion residues in treated wheat grain and its toxic effects on rats were investigated. Wheat grain was treated with [14C] malathion (specific activity: 2.76 MBq/mg) to determine the bioavailability of bound residues in rats. At the same time, grain was treated with nonlabeled malathion to test for possible toxic effects of bound residues in a subchronic (90 days) feeding study in rats at two dose levels. 10 and 100 ppm.It was observed that the level of malathion-bound residues amounted to 11.28% of the applied dose (for six months). Also, it was noted that the main route of [14C]-malathion excretion was through the urine. This signifies that grain-bound malathion was bioavailable. In subchronic test on rats bound malathion residues (both dose levels) induced effects to some extent in organ weight (spleen and adrenals), and blood ChE activity. In both, males and females, there was an increase in SGPT activity (lower dose), and in alkaline phosphatase in females (higher dose). Hematological data showed changes only in hemoglobin concentration in males (both dose levels).
文摘This study analyzes the level of total and bound pirimiphos-methyl residues in treated wheat grain and its toxic effects on rats.Wheat grain was treated with[(14)~C]pirimiphos-methyl of 16.36 mCi/mmol specific activity to determine the bioavailability of bound residues in rats.At the same time,grain was treated with nonlabeled pirimiphos-methyl as required to determine any possible toxic effects of bound residues in a subacute feeding study in rats.Two dose levels were used:10 and 100 ppm(the former being the recommended dose level in practical treatment). Estimation of the type of residues was performed at intervals of 0,30,90,120,150,and 180 days.During and after the animal feeding study,changes in body weight gain,organ weight, cholinesterase activity,serum enzyme activity,and hematology were investigated.There is an indication that bound residues of the pesticide pirimiphos-methyl provoke toxic effects to some extent.1989 Academic Press.Inc.
文摘This work proposes a 12 kW three-phase grid-connected single stage PWM DC-AC converter destined to process the energy provided by a photovoltaic array composed of 57 KC200GT PV modules with high power factor for any solar radiation. The PWM inverter modeling and the control strategy, using dqO transformation, are proposed in order to also allow the system operation as an active power filter, capable to compensate harmonic components and react power generated by the non-linear loads connected to the mains grid. An input voltage clamping technique is proposed to impose the photovoltaic operation on the maximum power point. Simulation and experimental results are presented to validate the proposed methodology for grid connected photovoltaic generation system.
文摘This work presents the design and control of the DAB （dual active bridge） converter employing gyrator＇s theory. A brief summary of the theory is introduced, and its application for the DAB converter is verified with a design example. After that, it develops the control and show results of simulations and experiment. Though the commutation not is studied, the advantage of method is the easy way for project and control of the DAB converter.
基金The fieldwork made by B.I.was supported by the Insti-tute for Biodiversity and Protected Areas(IBAP)of Guinea-BissauThe authors are very grateful to Dr.Luísa Nunes for the critical reading of the manuscript and to Philip Havik and Dora Castro from IICTsupported by Portuguese FCT grants:to MMR and MCD[HC/0075/2009],to LC[AFR/117785/2010].
文摘The sub-Saharan region holds a wide variety of indigenous plant species, still offering the possibility to discover very interesting new natural products with potential therapeutic value. Most of the African population depends on traditional medicine for primary health care, however, neurological disorders are often not considered as common diseases and many people with mental illnesses, like epilepsy, are severely affected by health-related stigma and discrimination. Epilepsy is the most common serious chronic brain disorder, estimated to affect at least 10 million people in Africa. Guinea-Bissau is located in West Africa, and its population is mainly rural with very few health services available. Since the earliest times, Guinea-Bissau flora has constituted the main source of materials used in folk medicine and the local population, who is well versed in the uses of these plants and their properties. The aim of this study was to document the existing knowledge and practices related to the treatment of neurological disorders, namely epilepsy and seizures, in Guinea-Bissau and in other West African countries. The results presented from this study provide information not only on the specific plants used to treat neurological disorders, but also on social knowledge brought in by various ethnic groups, each one having its own culture, beliefs and ways of nature appropriation. Taking into account the existing knowledge on the medicinal properties of plants for treatment of neurologic disorders, it is believed that research in the areas of ethnomedicine and ethnopharmacology in Guinea-Bissau can bring promising results capable of adding value to the very rich natural resources of this country of West Africa.
