Accurate evaluation of iron overload is necessary to establish the diagnosis of hemochromatosis and guide chelation treatment in transfusion-dependent anemia. The liver is the primary site for iron storage in patients...Accurate evaluation of iron overload is necessary to establish the diagnosis of hemochromatosis and guide chelation treatment in transfusion-dependent anemia. The liver is the primary site for iron storage in patients with hemochromatosis or transfusion-dependent anemia, therefore, liver iron concentration (LIC) accurately re? ects total body iron stores. In the past 20 years, magnetic resonance imaging (MRI) has emerged as a promising method for measuring LIC in a variety of diseases. We review the potential role of MRI in LIC determination in the most important disorders that are characterized by iron overload, that is, thalassemia major, other hemoglobinopathies, acquired anemia, and hemochromatosis. Most studies have been performed in thalassemia major and MRI is currently a widely accepted method for guiding chelation treatment in these patients. However, the lack of correlation between liver and cardiac iron stores suggests that both organs should be evaluated with MRI, since cardiac disease is the leading cause of death in this population. It is also unclear which MRI method is the most accurate since there are no large studies that have directly compared the different available techniques. The role of MRI in the era of genetic diagnosis of hemochromatosis is also debated, whereas data on the accuracy of the method in other hematological and liver diseases are rather limited. However, MRI is a fast, non-invasive and relatively accurate diagnostic tool for assessing LIC, and its use is expected to increase as the role of iron in the pathogenesis of liver disease becomes clearer.展开更多
目的比较TRIGEN Inter Tan系统与股骨近端防旋髓内钉（PFNA）内固定治疗老年股骨粗隆间骨折的疗效。方法自2010-01—2012-10分别采用TRIGEN Inter Tan（Smith＆Nephew公司提供）和PFNA（康辉公司提供）内固定治疗56例老年股骨粗隆间骨折...目的比较TRIGEN Inter Tan系统与股骨近端防旋髓内钉（PFNA）内固定治疗老年股骨粗隆间骨折的疗效。方法自2010-01—2012-10分别采用TRIGEN Inter Tan（Smith＆Nephew公司提供）和PFNA（康辉公司提供）内固定治疗56例老年股骨粗隆间骨折,其中Inter Tan内固定31例,PFNA内固定25例。比较2组手术时间、术中出血量、住院时间及髋关节功能Harris评分。结果 56例均获得平均17.3（9～20）个月随访,1例出现伤口脂肪液化延期愈合,其余无明显并发症。末次随访时骨折均骨性愈合,患者行走能力达到骨折前水平。与Inter Tan组相比,PFNA组手术时间较短、术中出血量较少,差异有统计学意义（P〈0.05）。2组住院时间、骨折愈合时间、末次随访时髋关节功能Harris评分差异均无统计学意义（P〉0.05）。结论 TRIGEN Inter Tan系统和PFNA均是治疗老年股骨粗隆间骨折的有效手术方法。展开更多
Soil salinization is a common phenomenon that affects both the environment and the socio-economy in arid and semi-arid regions; it is also an important aspect of land cover change. In this study, we integrated multi-s...Soil salinization is a common phenomenon that affects both the environment and the socio-economy in arid and semi-arid regions; it is also an important aspect of land cover change. In this study, we integrated multi-sensor remote sensing data with a field survey to analyze processes of soil salinization in a semi-arid area in China from 1979 to 2009. Generally, the area of salt-affected soils increased by 0.28% per year with remarkable acceleration from 1999 to 2009 （0.42% increase per year）. In contrast, the area of surface water bodies showed a decreasing trend （-0.08% per year） in the same period. Decreases in precipitation and increases in aridity due to annual （especially summer） warming provided a favorable condition for soil salinization. The relatively flat terrain favored waterlogging at the surface, and continuous drought facilitated upward movement of soil water and accumulation of surface saline and calcium. Meanwhile, land-use practices also played a crucial role in accelerating soil salinization. The conversion to cropland from natural vegetation greatly increased the demand for groundwater irrigation and aggravated the process of soil salinization. Furthermore, there are potential feedbacks of soil salinization to regional climate. The salinization of soils can limit the efficiency of plant water use as well as photosynthesis; therefore, it reduces the amount of carbon sequestrated by terrestrial ecosystem. Soil salinization also reduces the absorbed solar radiation by increasing land surface albedo. Such conversions of land cover significantly change the energy and water balance between land and atmosphere.展开更多
Utilization of polyvinylidene difluoride, PVDF, as the disperse phase and thermal plastic polyurethane, PU, as the continuous phase, the PU/PVDF blend hollow fiber membranes with the property of pressure-responsibilit...Utilization of polyvinylidene difluoride, PVDF, as the disperse phase and thermal plastic polyurethane, PU, as the continuous phase, the PU/PVDF blend hollow fiber membranes with the property of pressure-responsibility, PR, was prepared by melt.spinning. For these hollow fibers, the formation of the interracial micro-voids, IFM, and the spinablllty of the blend were analyzed. The pressm-e-responslblllty was studied by measuring the changing of pure water flux, PWF, with the pressure, and the influence of drawing and heat-setting on the structure and pressure-responsibility of the membranes were also discussed.展开更多
When designing a solar power plant, it is much more important to avoid the shadow on the PV Panels. As the shadow falls on the PV Panels;it significantly reduces the generation of required power as planned and designe...When designing a solar power plant, it is much more important to avoid the shadow on the PV Panels. As the shadow falls on the PV Panels;it significantly reduces the generation of required power as planned and designed. This research paper and case study will help a lot to avoid shadow, especially when selecting inter-row spacing between the strings of solar power plants.展开更多
文摘Accurate evaluation of iron overload is necessary to establish the diagnosis of hemochromatosis and guide chelation treatment in transfusion-dependent anemia. The liver is the primary site for iron storage in patients with hemochromatosis or transfusion-dependent anemia, therefore, liver iron concentration (LIC) accurately re? ects total body iron stores. In the past 20 years, magnetic resonance imaging (MRI) has emerged as a promising method for measuring LIC in a variety of diseases. We review the potential role of MRI in LIC determination in the most important disorders that are characterized by iron overload, that is, thalassemia major, other hemoglobinopathies, acquired anemia, and hemochromatosis. Most studies have been performed in thalassemia major and MRI is currently a widely accepted method for guiding chelation treatment in these patients. However, the lack of correlation between liver and cardiac iron stores suggests that both organs should be evaluated with MRI, since cardiac disease is the leading cause of death in this population. It is also unclear which MRI method is the most accurate since there are no large studies that have directly compared the different available techniques. The role of MRI in the era of genetic diagnosis of hemochromatosis is also debated, whereas data on the accuracy of the method in other hematological and liver diseases are rather limited. However, MRI is a fast, non-invasive and relatively accurate diagnostic tool for assessing LIC, and its use is expected to increase as the role of iron in the pathogenesis of liver disease becomes clearer.
文摘目的比较TRIGEN Inter Tan系统与股骨近端防旋髓内钉（PFNA）内固定治疗老年股骨粗隆间骨折的疗效。方法自2010-01—2012-10分别采用TRIGEN Inter Tan（Smith＆Nephew公司提供）和PFNA（康辉公司提供）内固定治疗56例老年股骨粗隆间骨折,其中Inter Tan内固定31例,PFNA内固定25例。比较2组手术时间、术中出血量、住院时间及髋关节功能Harris评分。结果 56例均获得平均17.3（9～20）个月随访,1例出现伤口脂肪液化延期愈合,其余无明显并发症。末次随访时骨折均骨性愈合,患者行走能力达到骨折前水平。与Inter Tan组相比,PFNA组手术时间较短、术中出血量较少,差异有统计学意义（P〈0.05）。2组住院时间、骨折愈合时间、末次随访时髋关节功能Harris评分差异均无统计学意义（P〉0.05）。结论 TRIGEN Inter Tan系统和PFNA均是治疗老年股骨粗隆间骨折的有效手术方法。
基金supported by the National Basic Research Program of China (Grant No.2009CB723904)the National Natural Science Foundation of China (Grant No. 41105076)+1 种基金the National Key technology R & D program (Grant No. 2012BAC22B04)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05090201)
文摘Soil salinization is a common phenomenon that affects both the environment and the socio-economy in arid and semi-arid regions; it is also an important aspect of land cover change. In this study, we integrated multi-sensor remote sensing data with a field survey to analyze processes of soil salinization in a semi-arid area in China from 1979 to 2009. Generally, the area of salt-affected soils increased by 0.28% per year with remarkable acceleration from 1999 to 2009 （0.42% increase per year）. In contrast, the area of surface water bodies showed a decreasing trend （-0.08% per year） in the same period. Decreases in precipitation and increases in aridity due to annual （especially summer） warming provided a favorable condition for soil salinization. The relatively flat terrain favored waterlogging at the surface, and continuous drought facilitated upward movement of soil water and accumulation of surface saline and calcium. Meanwhile, land-use practices also played a crucial role in accelerating soil salinization. The conversion to cropland from natural vegetation greatly increased the demand for groundwater irrigation and aggravated the process of soil salinization. Furthermore, there are potential feedbacks of soil salinization to regional climate. The salinization of soils can limit the efficiency of plant water use as well as photosynthesis; therefore, it reduces the amount of carbon sequestrated by terrestrial ecosystem. Soil salinization also reduces the absorbed solar radiation by increasing land surface albedo. Such conversions of land cover significantly change the energy and water balance between land and atmosphere.
基金Supported by the Fund of Ministry of Education (No.20040058002) and the Fund of Science Council of Tianjin (No.043102711)
文摘Utilization of polyvinylidene difluoride, PVDF, as the disperse phase and thermal plastic polyurethane, PU, as the continuous phase, the PU/PVDF blend hollow fiber membranes with the property of pressure-responsibility, PR, was prepared by melt.spinning. For these hollow fibers, the formation of the interracial micro-voids, IFM, and the spinablllty of the blend were analyzed. The pressm-e-responslblllty was studied by measuring the changing of pure water flux, PWF, with the pressure, and the influence of drawing and heat-setting on the structure and pressure-responsibility of the membranes were also discussed.
文摘When designing a solar power plant, it is much more important to avoid the shadow on the PV Panels. As the shadow falls on the PV Panels;it significantly reduces the generation of required power as planned and designed. This research paper and case study will help a lot to avoid shadow, especially when selecting inter-row spacing between the strings of solar power plants.
