Assessment of contaminants transport in a watershed affected by acid mine drainage,by coupling hydrological and geochemical modeling tools

Erini Stream (Thrace, northeastern Greece) is adversely affected by the presence of an abandoned mixed sulfide mine located in the upper watershed. The GIS based model SWAT (Soil Water and Assessment Tool) was applied to characterize hydrologic processes in the watershed. Model performance was evaluated by comparing the simulation results with field data including flow and concentration measurements from 12 monitoring points, for the time period from June 2005 to July 2006. Flow rate results indicated good agreement between simulated and measured data, with coefficient correlations R² in the range of 0.74–0.89. Simulation was focused on the dispersion of three pollutants, Zn, Cd and Mn. Using SWAT alone, simulation results systematically overestimated pollutants levels in Erini Stream.Geochemical model PHREEQC was used in combination with SWAT to obtain more accurate predictions regarding contaminants concentrations along the course of Erini Stream. The profiles of main metal contaminants, i.e. Zn, Cd and Mn, under wet conditions, were described with satisfactory precision assuming equilibrium with the carbonate minerals ZnCO₃·H₂O and otavite and partial supersaturation with respect to rhodochrosite. However, precipitation of discrete carbonate phases does not seem to be the predominant attenuation mechanism under dry conditions. Coprecipitation or sorption on the surface of precipitating calcite is another potential removal mechanism under these conditions.The methodology presented allows the reliable assessment of acid mine drainage impacts in the downstream aquatic environment and the design of effective measures for its mitigation based on an optimized number of monitoring data.     

Comparative Clinical Study of Bactigras and Telfa AMD for Skin Graft Donor-Site Dressing

The Bactigras^® paraffin tulle coated with chlorhexidine is normally used for the treatment of donor-site wounds in burn patients who received split-thickness skin grafts in several centers. It has some disadvantages, such as adhesion to wound surfaces and pain from the irritation caused by this dressing. The Telfa AMD^®, a non-adherent wound dressing which consists of absorbent cotton fibers impregnated with polyhexamethylene biguanide enclosed in a sleeve of thermoplastic polymers, is a new option for donor-site wound care which causes less adherence to the wound. The purpose of this study was to compare clinical efficacy of these two dressings for the management of donor-site wounds. Thirty-two patients who received split-thickness skin grafts by donor site harvesting from the thigh were enrolled in this study and randomized into two groups receiving either the Bactigras^® or the Telfa AMD^® wound treatment. Re-epithelialization, pain, infection and cost-effectiveness analyses were compared between both groups. The results showed that there was no significant difference in age, area of donor sites or length of hospital stays between the groups (p > 0.05). However, the day of re-epithelialization (≥90%) was significantly shorter in patients treated with the Telfa AMD^® compared to the Bactigras^® group (14.00 ± 3.05 vs. 9.25 ± 1.88 days for Bactigras^® and Telfa AMD^® groups, respectively, p < 0.001). The average pain score was also significantly lower in the Telfa AMD^® group (1.57 ± 0.55 vs. 4.70 ± 1.16, p < 0.001). There was no difference in the cost of treatment between the groups (4.64 ± 1.97 vs. 5.72 ± 2.54 USD, p = 0.19). This study indicated that the Telfa AMD^® was an effective dressing for the treatment of donor-site wounds.     

细菌在矿山酸性水形成和治理中的作用

矿山酸性废水是由于硫化矿物氧化而引起的污染问题,细菌加快了氧化反应的速度,在酸性水形成中起主要作用。由于氧化铁硫杆菌在Ｆｅ￣（２＋）氧化成Ｆｅ￣（３＋）时起催化作用,所以在酸性水处理中可利用细菌氧化代替空气氧化,再用ＣａＣＯ＿３使金属离子沉淀,从而降低了废水处理成本。     

磁处理对番茄幼苗MDH合成的影响

经磁处理的番茄(Lycopersicon esculeutum mill)幼苗苹果酸脱氢酶(malate dehydrogenase,MDH)活性增高,同工酶谱发生变化,出现新谱带．加放线菌素D(actinomycin D,AMD)后磁处理同工酶带中的新带消失,表明磁处理可能改变了基因表达的调控．而加AMD的磁处理组酶活仍高于相应的对照组,推测磁处理有可能对幼苗体内已有的MDH有活化作用．     

RESVEGA,a Nutraceutical Omega-3/Resveratrol Supplementation,Reduces Angiogenesis in a Preclinical Mouse Model of Choroidal Neovascularization

Age-related macular degeneration (AMD) is an eye disease that is characterized by damage to the central part of the retina, the macula, and that affects millions of people worldwide. At an advanced stage, a blind spot grows in the center of vision, severely handicapping patients with this degenerative condition. Despite therapeutic advances thanks to the use of anti-VEGF, many resistance mechanisms have been found to accentuate the visual deficit. In the present study, we explored whether supplementation with Resvega^®, a nutraceutical formulation composed of omega-3 fatty acids and resveratrol, a well-known polyphenol in grapes, was able to counteract laser-induced choroidal neovascularization (CNV) in mice. We highlight that Resvega^® significantly reduced CNV in mice compared with supplementations containing omega-3 or resveratrol alone. Moreover, a proteomic approach confirmed that Resvega^® could counteract the progression of AMD through a pleiotropic effect targeting key regulators of neoangiogenesis in retina cells in vivo. These events were associated with an accumulation of resveratrol metabolites within the retina. Therefore, a supplementation of omega-3/resveratrol could improve the management or slow the progression of AMD in patients with this condition.     

海洋平台结构振动的AMD主动控制试验研究

结合我国渤海JZ20—2MUQ平台的实际背景，设计制作了导管架式海洋平台结构1：10比例模型。利用传递函数法进行了平台结构模型的系统识别，并与有限元模型进行了比较。采用主动质量驱动控制系统(AMD)，利用容易实现的平台结构加速度输出反馈，设计并实现了平台结构的LQG控制算法。采用自行设计制作的AMD控制系统，进行了平台结构模型振动控制的地震模拟振动台试验，证实了AMD控制系统对平台结构良好的振动控制效果。本文的研究和结果为新建和现役平台结构的AMD振动控制应用奠定了基础。     

煤系黄铁矿氧化溶解地球化学动力学研究

对不同煤系的黄铁矿样品进行了氧化溶解动力学实验.研究表明，在模拟煤矿酸性水（pH≈2）的环境下，煤系黄铁矿的氧化速率随液相中Fe³⁺浓度的增加而增加，反应为Fe³⁺浓度的一级反应.温度对黄铁矿氧化反应速率有明显影响，温度每升高10 K，氧化速率平均增加约2倍.不同黄铁矿样品氧化溶解反应的活化能在50 kJ/mol以上，表明反应受表面反应的控制.不同来源煤系黄铁矿样品所含的杂质种类和含量不同，可能是造成其抗风化能力差异的重要因素，反映在其反应速率以及对温度的敏感程度，但反应机理基本一致.     

n-3多不饱和脂肪酸对中老年人群精神及视力影响的研究进展

通过综述n-3多不饱和脂肪酸对中老年人群疾病,特别是对中老年人群认知下降、老年痴呆、抑郁、黄斑变性等作用的研究,阐述了n-3多不饱和脂肪酸对认知下降风险的降低,以及对AMD病症发生的减缓作用。同时,n-3多不饱和脂肪酸在细胞中的含量与抑郁症发病率呈负相关性。尽管确切机理有待深入研究,但绝大部分临床研究表明,补充n-3多不饱和脂肪酸可以预防中老年人群精神及视力疾病的发生。     

Relative Contribution of Different Mitochondrial Oxidative Phosphorylation Components to the Retinal Pigment Epithelium Barrier Function: Implications for RPE-Related Retinal Diseases

Disruption of retinal pigment epithelial (RPE) barrier integrity is involved in the pathology of several blinding retinal diseases including age-related macular degeneration (AMD) and diabetic retinopathy (DR), but the underlying causes and pathophysiology are not completely well-defined. Mitochondria dysfunction has often been considered as a potential candidate implicated in such a process. In this study, we aimed to dissect the role of different mitochondrial components; specifically, those of oxidative phosphorylation (OxPhos), in maintaining the barrier functionality of RPE. Electric cell-substrate impedance sensing (ECIS) technology was used to collect multi-frequency electrical impedance data to assess in real-time the barrier formation of the RPE cells. For this purpose, the human retinal pigment epithelial cell line—ARPE-19—was used and treated with varying concentrations of specific mitochondrial inhibitors that target different steps in OxPhos: Rotenone for complex I (the largest protein complex in the electron transport chain (ETC)); oligomycin for ATP synthase; and carbonyl cyanide-p-trifluoromethoxyphenyl hydrazone (FCCP) for uncoupling ATP synthesis from the accompanying ETC. Furthermore, data were modeled using the ECIS-Zθ software to investigate in depth the effects of these inhibitors on three separate barrier parameters: cell–cell interactions (R_b), cell–matrix interactions (α), and the cell membrane capacitance (C_m). The viability of ARPE-19 cells was determined by lactate dehydrogenase (LDH) Cytotoxicity Assay. The ECIS program’s modeling demonstrated that FCCP and thus OxPhos uncoupling disrupt the barrier function in the ARPE-19 cells across all three components of the total resistance (Rb, α, and C_m) in a dose-dependent manner. On the other hand, oligomycin and thus ATP synthase inhibition mostly affects the ARPE-19 cells’ attachment to their substrate evident by a significant decrease in α resistance in a dose-dependent manner, both at the end and throughout the duration of the experiment. On the contrary, rotenone and complex I inhibition mostly affect the ARPE-19 paracellular resistance R_b in a dose-dependent manner compared to basolateral resistance α or C_m. Our results clearly demonstrate differential roles for different mitochondrial components in maintaining RPE cell functionality in which uncoupling of OxPhos is a major contributing factor to the disruption barrier function. Such differences can be used in investigating gene expression as well as for screening of selective agents that improve the OxPhos coupling efficiency to be used in the therapeutic approach for treating RPE-related retinal diseases.     

AMD-Like Substrate Causes Epithelial Mesenchymal Transition in iPSC-Derived Retinal Pigment Epithelial Cells Wild Type but Not C3-Knockout

The Bruch’s membrane (BrM) is a five-layered extracellular matrix (ECM) that supports the retinal pigment epithelium (RPE). Normal age-related changes in the BrM may lead to RPE cell damage and ultimately to the onset and progression of age-related macular degeneration (AMD), which is the most common cause of visual loss among the elderly. A role for the complement system in AMD pathology has been established, but the disease mechanisms are poorly understood, which hampers the design of efficient therapies to treat millions of patients. In an effort to identify the mechanisms that lead from normal aging to pathology, we have developed a cell-based model using complement deficient human induced pluripotent stem cell (iPSC)-derived RPE cells cultured on an AMD-like ECM that mimics BrM. The data present evidence that changes in the ECM result in loss of differentiation and promote epithelial mesenchymal transition (EMT) of healthy RPE cells. This pathological process is mediated by complement activation and involves the formation of a randomly oriented collagen meshwork that drives the dedifferentiation of the RPE monolayer. Genetic ablation of complement component 3 has a protective effect against EMT but does not prevent the abnormal deposition of collagens. These findings offer new insights into the sequence of events that initiate AMD and may guide the design of efficient therapies to treat this disease with unmet medical needs.