Iron deficiency (ID), defined as an insufficient supply of iron to the cells of the body after iron reserves have been exhausted, is the most prevalent single nutritional deficiency, affecting over 2, 000 million peop...Iron deficiency (ID), defined as an insufficient supply of iron to the cells of the body after iron reserves have been exhausted, is the most prevalent single nutritional deficiency, affecting over 2, 000 million people, mostly in the developing world. Infants, small children, adolescents and pregnant and fertile-age women are most vulnerable. Only about 50 % of people with ID develop iron deficiency anemia (IDA), since this is a late manifes tation of chronic ID. Based on the average daily iron requirement and on the rate of iron reutilization from red cell hemoglobin destruction, it can be estimated that after iron stores have been depleted, it takes about 4 months of ID erythropoiesis for adult women to have a drop in hemoglobin concentration [Hb] of 10 g/l, if the iron intake is only 70 % of requirement. IDA can be defined by a [Hb] below an appropriate cut-off point for age,sex, physiological condition and altitude above sea level, or by a [Hb] increment of morethan 10 g/l to the administration of adequate doses of iron. More than 85 % of the nutritional anemias are IDA alone, or of iron combined with folate or other nutrient deficiencies [WHO/UNICEF/UNU, 1997; Yip, 1994].展开更多
This paper presents the effects of chemical compositions of austempered ductile iron(ADI)on casting quality,heat treatment process parameters and mechanical properties of final products.Through experiment and producti...This paper presents the effects of chemical compositions of austempered ductile iron(ADI)on casting quality,heat treatment process parameters and mechanical properties of final products.Through experiment and production practice,the impacts of carbon equivalent on ADI and its mechanical properties have been studied. Proper content ranges for carbon and silicon have been obtained to avoid ADI casting shrinkage and graphite floatation,as well as to achieve the optimal mechanical properties.According to the impact of silicon content on austenite phase transformation,the existing form of carbon in ADI has been analyzed,and also the formula and diagram showing the relationship between austenitizing temperature and carbon content in austenite have been deduced.The chemical composition range for high performance ADI and its control points have been recommended, to serve as a reference for production process.展开更多
Iron overload increases the risk of diabetes via mechanisms of abnormal glucose metabolism: insulin deficiency, insulin resistance, and/or hepatic dysfunction. Iron reduction upregulates glucose uptake and improves he...Iron overload increases the risk of diabetes via mechanisms of abnormal glucose metabolism: insulin deficiency, insulin resistance, and/or hepatic dysfunction. Iron reduction upregulates glucose uptake and improves hepatocytes insulin receptor activity. This study was conducted to examine the effects of iron depletion—via controlled phlebotomy—on the hypoglycemic treatment in poorly controlled type 2 diabetes mellitus (T2DM) patients with non-genetic iron overload. Forty three patients with poorly controlled T2DM and iron overload were divided into 2 groups: iron depletion group and control group. Regular phlebotomy was performed for iron depletion group on monthly basis until serum ferritin reached 20 μg/L or less. Both groups were examined and compared for blood pressure, serum ferritin, lipid profile, HFE-gene, HbA1c, HOMA-IR and number of medicines used for diabetic control. The results had revealed that group differences of HbA1c (-2.64, 95% CI -3.23 to 2.04, p < 0.001) and HOMA-IR (-0.68, 95% CI -0.98 to -0.37, p < 0.001) showed significant decreases in iron depletion group at end of study. Significant decrease in the numbers of hypoglycemic medicines in iron depletion group was shown at end of study (p < 0.001);66.7% of iron depletion group patients were receiving 1 or 2 medicines at end of studyversus none of the control group. Diastolic blood pressure (DBP), triglycerides and LDL-C decreased significantly while HDL-C levels showed significant rise after iron depletion. It can be concluded from the present study that iron depletion therapy is beneficial for improving the efficiency of glycemic control, DBP, and dyslipidemia in poorly controlled type 2 diabetics with iron over load.展开更多
The present study investigated quantitatively the significance of HNLC (high-nutrient low-chlorophyll) regions and its grazing control with the improved iron fertilization for climate change. The limitation of iron (F...The present study investigated quantitatively the significance of HNLC (high-nutrient low-chlorophyll) regions and its grazing control with the improved iron fertilization for climate change. The limitation of iron (Fe) for phytoplankton growth in HNLC regions was confirmed by sulfur compounds (S) such as volcanic ash and hydrogen sulfide (H2S) in batch cultures, whose chemical sediment of Fe3S4 showed 4.06 wt%. The technologies developed for iron fertilization since 1993 till now were not practical to provide sufficient amounts of bioavailable iron due to sedimentary iron sulfides induced by undersea volcanic sulfur compounds. The proposed technology for iron fertilization was improved to enhance the bioavailable iron to phytoplankton by keeping minimal sulfur compounds in HNLC regions. The low productivity of phytoplankton by grazing control in HNLC regions was 6% diatoms whose 52% was grazed by copepods and 42% by krill on the basis of data analysis in 2000 EisenEx Experiment at boundary of Antarctic and African tectonic plates. All of the previous iron fertilization experiments were conducted at volcanic sulfur compounds enriched HNLC regions. The present study revealed that the enhanced phytoplankton productivity in batch culture without sedimentary iron sulfides can be possible only if sulfur compounds are minimal, as is in Shag Rocks (53°S, 42°W) of South Georgia in Scotia Sea in the Southern Ocean.展开更多
A supported iron catalyst, which was prepared by anchoring FeCl2/FeCl3 on the cross-linking macroporous polyacrylate ion exchange resin, was evaluated via the controlled radical polymerization. When a small amount of ...A supported iron catalyst, which was prepared by anchoring FeCl2/FeCl3 on the cross-linking macroporous polyacrylate ion exchange resin, was evaluated via the controlled radical polymerization. When a small amount of CuCl2/ Me6TREN was added, the controllability of the polymerization over the iron-mediated catalyst was significantly improved（Mw/Mn = 1.23-1.73 ）, affording a polymer with a low residual metal via a simple catalyst separation procedure. After suitable regeneration, the supported iron catalyst could also he recycled. UV-Vis analysis showed that the additional copper catalyst could facilitate the radical deactivation process.展开更多
In the present research, TTT curve of bainitic ductile iron under the condition of controlled cooling was generated. The cooling rate of grinding ball and its temperature distribution were also measured at the same ti...In the present research, TTT curve of bainitic ductile iron under the condition of controlled cooling was generated. The cooling rate of grinding ball and its temperature distribution were also measured at the same time. It can be concluded that the bainitic zone of TTT curve is separated from the pearlitic zone. As compared to the water-quenching condition, more even cooling rate and temperature distribution can be achieved in the controlled cooling process. The controlled cooling can keep away from pearlitic zone in the high temperature cooling stage and produce similar results to the process of traditional isothermal cooling with a low cooling rate in the low temperature cooling stage.展开更多
Cerium-substituted yttrium iron garnet(Ce x Y 3-xFe 5O 12, Ce∶YIG) was prepared via coprecipitation. The structu re, morphology, valence state and constituent of Ce ions were investigated respe ctively. X-ra...Cerium-substituted yttrium iron garnet(Ce x Y 3-xFe 5O 12, Ce∶YIG) was prepared via coprecipitation. The structu re, morphology, valence state and constituent of Ce ions were investigated respe ctively. X-ray powder diffraction(XRD) analysis shows that Ce∶YIG was of singl e cubic YIG phase. The result of X-ray photoelectron spectroscopy(XPS) indicate s the Ce ions in Ce∶YIG were in the state of trivalence. Scanning electron micr oscope(SEM) demonstrates the conglobation of Ce∶YIG particles about 0.2μm scal e.The magnetic properties were studied by a vibrating sample magnetometer(VSM) a nd the result exhibits that substitution of Ce 3+ changes the magnetic para meters of YIG. The effects of doping content of Ce ions and synthesis temperatu re on valence control were discussed in detail.展开更多
文摘Iron deficiency (ID), defined as an insufficient supply of iron to the cells of the body after iron reserves have been exhausted, is the most prevalent single nutritional deficiency, affecting over 2, 000 million people, mostly in the developing world. Infants, small children, adolescents and pregnant and fertile-age women are most vulnerable. Only about 50 % of people with ID develop iron deficiency anemia (IDA), since this is a late manifes tation of chronic ID. Based on the average daily iron requirement and on the rate of iron reutilization from red cell hemoglobin destruction, it can be estimated that after iron stores have been depleted, it takes about 4 months of ID erythropoiesis for adult women to have a drop in hemoglobin concentration [Hb] of 10 g/l, if the iron intake is only 70 % of requirement. IDA can be defined by a [Hb] below an appropriate cut-off point for age,sex, physiological condition and altitude above sea level, or by a [Hb] increment of morethan 10 g/l to the administration of adequate doses of iron. More than 85 % of the nutritional anemias are IDA alone, or of iron combined with folate or other nutrient deficiencies [WHO/UNICEF/UNU, 1997; Yip, 1994].
基金supported by the key project for Science and Technology of Hubei Provincial Department of Education(No.D20101606)the Scientific and Technological Project of China Textile Industry Association(No.2008085)
文摘This paper presents the effects of chemical compositions of austempered ductile iron(ADI)on casting quality,heat treatment process parameters and mechanical properties of final products.Through experiment and production practice,the impacts of carbon equivalent on ADI and its mechanical properties have been studied. Proper content ranges for carbon and silicon have been obtained to avoid ADI casting shrinkage and graphite floatation,as well as to achieve the optimal mechanical properties.According to the impact of silicon content on austenite phase transformation,the existing form of carbon in ADI has been analyzed,and also the formula and diagram showing the relationship between austenitizing temperature and carbon content in austenite have been deduced.The chemical composition range for high performance ADI and its control points have been recommended, to serve as a reference for production process.
文摘Iron overload increases the risk of diabetes via mechanisms of abnormal glucose metabolism: insulin deficiency, insulin resistance, and/or hepatic dysfunction. Iron reduction upregulates glucose uptake and improves hepatocytes insulin receptor activity. This study was conducted to examine the effects of iron depletion—via controlled phlebotomy—on the hypoglycemic treatment in poorly controlled type 2 diabetes mellitus (T2DM) patients with non-genetic iron overload. Forty three patients with poorly controlled T2DM and iron overload were divided into 2 groups: iron depletion group and control group. Regular phlebotomy was performed for iron depletion group on monthly basis until serum ferritin reached 20 μg/L or less. Both groups were examined and compared for blood pressure, serum ferritin, lipid profile, HFE-gene, HbA1c, HOMA-IR and number of medicines used for diabetic control. The results had revealed that group differences of HbA1c (-2.64, 95% CI -3.23 to 2.04, p < 0.001) and HOMA-IR (-0.68, 95% CI -0.98 to -0.37, p < 0.001) showed significant decreases in iron depletion group at end of study. Significant decrease in the numbers of hypoglycemic medicines in iron depletion group was shown at end of study (p < 0.001);66.7% of iron depletion group patients were receiving 1 or 2 medicines at end of studyversus none of the control group. Diastolic blood pressure (DBP), triglycerides and LDL-C decreased significantly while HDL-C levels showed significant rise after iron depletion. It can be concluded from the present study that iron depletion therapy is beneficial for improving the efficiency of glycemic control, DBP, and dyslipidemia in poorly controlled type 2 diabetics with iron over load.
文摘The present study investigated quantitatively the significance of HNLC (high-nutrient low-chlorophyll) regions and its grazing control with the improved iron fertilization for climate change. The limitation of iron (Fe) for phytoplankton growth in HNLC regions was confirmed by sulfur compounds (S) such as volcanic ash and hydrogen sulfide (H2S) in batch cultures, whose chemical sediment of Fe3S4 showed 4.06 wt%. The technologies developed for iron fertilization since 1993 till now were not practical to provide sufficient amounts of bioavailable iron due to sedimentary iron sulfides induced by undersea volcanic sulfur compounds. The proposed technology for iron fertilization was improved to enhance the bioavailable iron to phytoplankton by keeping minimal sulfur compounds in HNLC regions. The low productivity of phytoplankton by grazing control in HNLC regions was 6% diatoms whose 52% was grazed by copepods and 42% by krill on the basis of data analysis in 2000 EisenEx Experiment at boundary of Antarctic and African tectonic plates. All of the previous iron fertilization experiments were conducted at volcanic sulfur compounds enriched HNLC regions. The present study revealed that the enhanced phytoplankton productivity in batch culture without sedimentary iron sulfides can be possible only if sulfur compounds are minimal, as is in Shag Rocks (53°S, 42°W) of South Georgia in Scotia Sea in the Southern Ocean.
文摘A supported iron catalyst, which was prepared by anchoring FeCl2/FeCl3 on the cross-linking macroporous polyacrylate ion exchange resin, was evaluated via the controlled radical polymerization. When a small amount of CuCl2/ Me6TREN was added, the controllability of the polymerization over the iron-mediated catalyst was significantly improved（Mw/Mn = 1.23-1.73 ）, affording a polymer with a low residual metal via a simple catalyst separation procedure. After suitable regeneration, the supported iron catalyst could also he recycled. UV-Vis analysis showed that the additional copper catalyst could facilitate the radical deactivation process.
文摘In the present research, TTT curve of bainitic ductile iron under the condition of controlled cooling was generated. The cooling rate of grinding ball and its temperature distribution were also measured at the same time. It can be concluded that the bainitic zone of TTT curve is separated from the pearlitic zone. As compared to the water-quenching condition, more even cooling rate and temperature distribution can be achieved in the controlled cooling process. The controlled cooling can keep away from pearlitic zone in the high temperature cooling stage and produce similar results to the process of traditional isothermal cooling with a low cooling rate in the low temperature cooling stage.
文摘Cerium-substituted yttrium iron garnet(Ce x Y 3-xFe 5O 12, Ce∶YIG) was prepared via coprecipitation. The structu re, morphology, valence state and constituent of Ce ions were investigated respe ctively. X-ray powder diffraction(XRD) analysis shows that Ce∶YIG was of singl e cubic YIG phase. The result of X-ray photoelectron spectroscopy(XPS) indicate s the Ce ions in Ce∶YIG were in the state of trivalence. Scanning electron micr oscope(SEM) demonstrates the conglobation of Ce∶YIG particles about 0.2μm scal e.The magnetic properties were studied by a vibrating sample magnetometer(VSM) a nd the result exhibits that substitution of Ce 3+ changes the magnetic para meters of YIG. The effects of doping content of Ce ions and synthesis temperatu re on valence control were discussed in detail.
