Heavy metals: confounding factors in the response of New Zealand freshwater fish assemblages to natural and anthropogenic acidity

Acidification of freshwaters is a global phenomenon, occurring both through natural leaching of organic acids and through human activities from industrial emissions and mining. The West Coast of the South Island, New Zealand, has both naturally acidic and acid mine drainage (AMD) streams enabling us to investigate the response of fish communities to a gradient of acidity in the presence and absence of additional stressors such as elevated concentrations of heavy metals. We surveyed a total of 42 streams ranging from highly acidic (pH 3.1) and high in heavy metals (10 mg L⁻¹ Fe; 38 mg L⁻¹ Al) to circum-neutral (pH 8.1) and low in metals (0.02 mg L⁻¹ Fe; 0.05 mg L⁻¹ Al). Marked differences in pH and metal tolerances were observed among the 15 species that we recorded. Five Galaxias species, Anguilla dieffenbachii and Anguillaaustralis were found in more acidic waters (pH< 5), while bluegill bullies (Gobiomorphus hubbsi) and torrentfish (Cheimarrichthys fosteri) were least tolerant of low pH (minimum pH 6.2 and 5.5, respectively). Surprisingly, the strongest physicochemical predictor of fish diversity, density and biomass was dissolved metal concentrations (Fe, Al, Zn, Mn and Ni) rather than pH. No fish were detected in streams with dissolved metal concentrations > 2.7 mg L⁻¹ and nine taxa were only found in streams with metal concentrations < 1 mg L⁻¹. The importance of heavy metals as critical drivers of fish communities has not been previously reported in New Zealand, although the mechanism of the metal effects warrants further study. Our findings indicate that any remediation of AMD streams which seeks to enable fish recolonisation should aim to improve water quality by raising pH above ≈ 4.5 and reducing concentrations of dissolved Al and Fe to < 1.0 mg L⁻¹.     

透过专利看微处理器的技术发展（五）——浅谈主要专利权人技术发展

本文在调研大量专利文献的基础上,通过跟踪微处理器的主要专利权人IBM、Intel和AMD在中国的微处理器专利,研究其不同时期技术重点,明确其技术发展历程。同时从技术分布、典型芯片结构对比、专利申请增长率以及法律状态几个方面分析了微处理器的专利技术演进,并分析近期专利技术的特征,以及技术要素的变化,分析各厂商的专利技术现状,预测发展方向,为新产品开发计划提供线索。     

Retinal Pigment Epithelium Expressed Toll-like Receptors and Their Potential Role in Age-Related Macular Degeneration

(1) Background: Inflammation is a major pathomechanism in the development and progression of age-related macular degeneration (AMD). The retinal pigment epithelium (RPE) may contribute to retinal inflammation via activation of its Toll-like receptors (TLR). TLR are pattern recognition receptors that detect the pathogen- or danger-associated molecular pattern. The involvement of TLR activation in AMD is so far not understood. (2) Methods: We performed a systematic literature research, consulting the National Library of Medicine (PubMed). (3) Results: We identified 106 studies, of which 54 were included in this review. Based on these studies, the current status of TLR in AMD, the effects of TLR in RPE activation and of the interaction of TLR activated RPE with monocytic cells are given, and the potential of TLR activation in RPE as part of the AMD development is discussed. (4) Conclusion: The activation of TLR2, -3, and -4 induces a profound pro-inflammatory response in the RPE that may contribute to (long-term) inflammation by induction of pro-inflammatory cytokines, reducing RPE function and causing RPE cell degeneration, thereby potentially constantly providing new TLR ligands, which could perpetuate and, in the long run, exacerbate the inflammatory response, which may contribute to AMD development. Furthermore, the combined activation of RPE and microglia may exacerbate neurotoxic effects.     

广州电视塔直线电机驱动的主动质量阻尼器动力特性研究

针对广州电视塔的振动控制，提出了直线电机驱动的主动质量阻尼器控制装置实现策略，分别进行了多个直线电机驱动的2个阻尼器子系统的指令力、反馈驱动力、实际驱动力、控制系统、软件限速、软件限位，以及2个子系统一致性和时滞的性能实测，提出了多个直线电机驱动单个主动质量阻尼器的纹波推力和综合阻力识别方法及计算公式。实测结果表明：提出的广州电视塔多个直线电机驱动的主动质量阻尼器控制装置实现策略可行，广州电视塔2个阻尼器子系统能稳定地接收指令力与实现指令力，软件限位及限速安全系统工作良好；提出的多个直线电机驱动单个主动质量阻尼器的纹波推力和综合阻力识别方法及计算公式能较好地识别直线电机驱动的主动质量阻尼器动力特性；2个阻尼器子系统能同步工作且时滞较小，满足广州电视塔振动控制的要求。     

含膳食抗氧化剂的食品与老年性黄斑变性的防治

老年性黄斑变性是老年人最主要的视力损伤和致盲原因之一。视网膜的高耗氧性、高不饱和脂肪含量和其暴露于可见光的特性使其易于受到氧化损伤。联合应用膳食抗氧化剂有助于控制老年性黄斑变性的发展。含膳食抗氧化剂的食品对于老年性黄斑变性的防治是十分有意义的。应认真评价老年人的食品结构和饮食状况,根据评价指导其更合理的饮食。老年人应在日常生活中多食用含膳食抗氧化剂丰富的食品。     

Anti‐VEGF‐Aptamer Modified C‐Dots—A Hybrid Nanocomposite for Topical Treatment of Ocular Vascular Disorders

The vascular endothelial growth factor (VEGF) induces pathological angiogenetic ocular diseases. It is a scientific challenge to develop carriers for the controlled release of inhibitors for VEGF present in the back of the eye domain. Carbon dots (C‐dots) functionalized with the VEGF aptamer are introduced and the hybrid nanoparticles are used for ocular nanomedicine. The C‐dots are applied as effective carriers of the anti‐VEGF aptamer across the cornea, yielding therapeutic levels upon topical administration. The hybrids show no toxicity for both in vitro and in vivo murine animal model, and further enable noninvasive intraocular concentration monitoring through the C‐dots inherent fluorescence. In addition, the hybrid C‐dots effectively inhibit VEGF‐stimulated angiogenesis in choroidal blood vessels. This inhibition is comparable to two commercially available anti‐VEGF drugs, bevacizumab and aflibercept. The hybrid aptamer‐modified C‐dots provide a versatile nanomaterial to treat age‐related macular degeneration and diabetic retinopathy.     

Geochemical and Stable Isotope Evidence for Precipitation and Groundwater Sourcing of Recharge at the Green Valley Site,Vigo County,Indiana

Abstract  We examined the recharge sources of acid mine drainage (AMD) seeps that form at the toe of the coal refuse (gob) pile at a site in Indiana, using traditional geochemistry and oxygen isotopes. AMD from this site has impacted local waterways, and reducing the volume of AMD is a priority. Our observations indicate that there are two main sources of recharge. The first is relatively dilute, isotopically homogenous, geochemically-reducing groundwater that flows up through pre-mining karst-like features beneath the gob pile due to localized, precipitation-induced, hydraulic head. This produces a perched water table above the regional water table. The second source of recharge is oxidizing and isotopically variable meteoric precipitation that percolates through the permeable capping material; a partially buried and abandoned railroad grade may also channel meteoric waters into the pile. During periods of low precipitation, oxygenated pore moisture in the unsaturated zone facilitates AMD generation. During periods of elevated precipitation, these metal-rich pore fluids are flushed through the system by isotopically variable, oxygenated, metal-poor meteoric waters. Each source contributes subequal but variable amounts of recharge waters. The hydraulic conductivity and permeability of the gob pile, as calculated by isotopic lag, is consistent with values for silty to clean unconsolidated sand.Electronic Supplementary Material  Electronic Supplementary Material is available for this article if you access it at     

基于振动特性判别钢管混凝土两种材料间的脱粘规律

通过钢管混凝土推出试验,分析比较推出过程中各阶段钢管混凝土非线性振动特性的差异,研究影响钢管混凝土非线性特性的因素。利用解析模式分解提取钢管混凝土振动信号的第一阶振动分量,通过Hilbert变换得到频率振幅关系,分析钢管混凝土的非线性振动特性。3根钢管混凝土构件试验结果表明,构件非线性在整个加载过程中呈现出先增大后减小的变化趋势,钢管混凝土非线性振动特性受其界面作用影响。在未发生加载脱粘的情况下,混凝土浇筑质量不良将削弱其界面的胶结作用,从而降低非线性特性。     

Protective Effects of Resveratrol against UVA-Induced Damage in ARPE19 Cells

Ultraviolet radiation, especially UVA, can penetrate the lens, reach the retina, and induce oxidative stress to retinal pigment epithelial (RPE) cells. Even though it is weakly absorbed by protein and DNA, it may trigger the production of reactive oxygen species (ROS) and generate oxidative injury; oxidative injury to the retinal pigment epithelium has been implicated to play a contributory role in age-related macular degeneration (AMD). Studies showed that resveratrol, an abundant and active component of red grapes, can protect several cell types from oxidative stress. In this study, adult RPE cells being treated with different concentrations of resveratrol were used to evaluate the protective effect of resveratrol on RPE cells against UVA-induced damage. Cell viability assay showed that resveratrol reduced the UVA-induced decrease in RPE cell viability. Through flow cytometry analysis, we found that the generation of intracellular H₂O₂ induced by UVA irradiation in RPE cells could be suppressed by resveratrol in a concentration-dependent manner. Results of Western blot analysis demonstrated that resveratrol lowered the activation of UVA-induced extracellular signal-regulated kinase, c-jun-NH₂ terminal kinase and p38 kinase in RPE cells. In addition, there was also a reduction in UVA-induced cyclooxygenase-2 (COX-2) expression in RPE cells pretreated with resveratrol. Our observations suggest that resveratrol is effective in preventing RPE cells from being damaged by UVA radiation, and is worth considering for further development as a chemoprotective agent for the prevention of early AMD.