Gold Nanorods Electrostatically Binding Nucleic Acid Probe for In Vivo MicroRNA Amplified Detection and Photoacoustic Imaging‐Guided Photothermal Therapy

Developing a comprehensive platform which has both diagnosis and therapeutic strategies is necessary for efficient tumor treatment. In this work, a F uel I mproved micro R NA E xplorer (FIRE) probe with signal amplification capability is designed for sensitive detection of microRNA‐21 (miR‐21), which is upregulated in most tumor cells. Besides, FIRE could be loaded by polyethylenimine (PEI)‐modified gold nanorods (AuNR‐PEI) via facile electrostatic interaction, which could avoid the complicated processes commonly used to covalently conjugate nucleic acid probes onto AuNRs. The as‐fabricated AuNR‐PEI/FIRE system could efficiently distinguish tumor cells from non‐tumor cells. The fluorescence signals in MCF‐7 breast carcinoma and HeLa cervical carcinoma cells treated with AuNR‐PEI/FIRE are enhanced 7‐ and 4.5‐fold, respectively, compared with non‐amplification system. AuNR‐PEI/FIRE improves tumor detection ability in vivo and exhibits excellent tumor inhibition efficacy under the fluorescence imaging and photoacoustic imaging guided photothermal therapy. This is the first time to utilize the combined application of amplified nucleic acid detection and photothermal effect derived from gold nanorods together with PA imaging in a facile manner to provide a promising theranostic strategy for accurate diagnosis and tumor therapy.     

Integrated ultrafiltration-nanofiltration membrane processes applied to the treatment of gold mining effluent: Influence of feed pH and temperature

This study aimed to evaluate the effect of feed pH (2.2 - original effluent pH – up to 6.0) and temperature (20 up to 40°C) on the performance of integrated ultrafiltration (UF) and nanofiltration (NF) applied to gold mining effluent. pH increase led to a significant decrease in UF permeate flux. NF showed high retention efficiencies of ions when temperature was below 30°C. Retention of high-valence counter-ions to balance the charge of retained co-ions seemed to be the strongest NF mechanisms. Process performance at feed pH of 5.0 was superior in terms of fouling, retention efficiency, and investment cost.     

纳米金棒诱导A549细胞产生自噬的机制研究

纳米金棒(AuNRs)具有众多独特的属性,已广泛运用于生物医学领域,但其是否具有潜在的生物危害尚有争议.作者运用了激光扫描共聚焦显微镜技术、western blotting技术和其他分子生物学方法从细胞氧化应激的角度探讨了AuNRs诱导A549细胞产生自噬的分子机制.研究结果表明,4μg·mL-1的AuNRs处理6 h能够诱导A549细胞自噬标志蛋白LC3-Ⅱ表达增加,LC3蛋白从细胞核转移至细胞质并形成自噬小泡.进一步研究发现,AuNRs能够降低A549细胞线粒体膜电位、ATP含量、UCP2蛋白表达水平以及细胞抗氧化能力并导致活性氧蓄积,后者可能最终引起细胞产生自噬.而10 mmol·L-1抗氧化剂NAC能够逆转上述线粒体及细胞功能的改变,并抑制自噬的发生.这一研究为深入认识其生物危害及可能机制提供了有力的实验证据.     

电镀银/钯/硬金组合耐磨镀层工艺研究

为了提高镀硬金导电环的耐磨性,在黄铜基材上电镀铜/钯/硬金、镍/钯/硬金和银/钯/硬金三种组合镀层,通过工艺实验,组合镀层的外观、厚度、结合力、硬度、接触电阻及表面微观形貌等性能测试,以及装配后耐磨性能考核试验,发现银/钯/硬金组合镀层耐磨性最好。结果表明,该镀层耐磨可达100万次,能够满足产品抗磨性要求。     

Cancer Cell Membrane‐Coated Gold Nanocages with Hyperthermia‐Triggered Drug Release and Homotypic Target Inhibit Growth and Metastasis of Breast Cancer

The cell‐specific targeting drug delivery and controlled release of drug at the cancer cells are still the main challenges for anti‐breast cancer metastasis therapy. Herein, the authors first report a biomimetic drug delivery system composed of doxorubicin (DOX)‐loaded gold nanocages (AuNs) as the inner cores and 4T1 cancer cell membranes (CMVs) as the outer shells (coated surface of DOX‐incorporated AuNs (CDAuNs)). The CDAuNs, perfectly utilizing the natural cancer cell membranes with the homotypic targeting and hyperthermia‐responsive ability to cap the DAuNs with the photothermal property, can realize the selective targeting of the homotypic tumor cells, hyperthermia‐triggered drug release under the near‐infrared laser irradiation, and the combination of chemo/photothermal therapy. The CDAuNs exhibit a stimuli‐release of DOX under the hyperthermia and a high cell‐specific targeting of the 4T1 cells in vitro. Moreover, the excellent combinational therapy with about 98.9% and 98.5% inhibiting rates of the tumor volume and metastatic nodules is observed in the 4T1 orthotopic mammary tumor models. As a result, CDAuNs can be a promising nanodelivery system for the future therapy of breast cancer.     

Plasmonic Dual‐Enhancement and Precise Color Tuning of Gold Nanorod@SiO2 Coupled Core–Shell–Shell Upconversion Nanocrystals

The last decade has witnessed the remarkable research progress of lanthanide‐doped upconversion nanocrystals (UCNCs) at the forefront of promising applications. However, the future development and application of UCNCs are constrained greatly by their underlying shortcomings such as significant nonradiative processes, low quantum efficiency, and single emission colors. Here a hybrid plasmonic upconversion nanostructure consisting of a GNR@SiO₂ coupled with NaGdF₄:Yb³⁺,Nd³⁺@NaGdF₄:Yb³⁺,Er³⁺@NaGdF₄ core–shell–shell UCNCs is rationally designed and fabricated, which exhibits strongly enhanced UC fluorescence (up to 20 folds) and flexibly tunable UC colors. The experimental findings show that controlling the SiO₂ spacer thickness enables readily manipulating the intensity ratio of the Er³⁺ red, green, and blue emissions, thereby allowing us to achieve the emission color tuning from pale yellow to green upon excitation at 808 nm. Electrodynamic simulations reveal that the tunable UC colors are due to the interplay of plasmon‐mediated simultaneous excitation and emission enhancements in the Er³⁺ green emission yet only excitation enhancement in the blue and red emissions. The results not only provide an upfront experimental design for constructing hybrid plasmonic UC nanostructures with high efficiency and color tunability, but also deepen the understanding of the interaction mechanism between the Er³⁺ emissions and plasmon resonances in such complex hybrid nanostructure.     

甘肃西成地区金矿石英脉与金矿化关系研究

甘肃西成地区金矿床主要产在中泥盆统西汉水组和安家岔组的浅变质细碎屑岩中，金矿化类型为细脉浸染型，含金石英脉和脉旁蚀变围岩共同构成工业矿体。金矿化强度与石英脉带的规模和脉体内、外黄铁矿的含量成正比；与石英脉带的规整程度和脉体厚度成反比。一般情况下，从石英脉带的中心→边部→远离脉带，金品位渐次降低；围岩矿化与蚀变强度和旁侧石英脉的含金量成正比。石英脉带是宏观上直观的找矿标志。这种矿化规律与陕西八卦庙特大型金矿床非常相似，显示本区具有良好的成矿条件和巨大的找矿前景     

X射线荧光法在燕山地区金矿勘查中的研究与应用

本文论述了Ｘ射线荧光法勘查金矿的地质、地球化学依据和物理基础，提出了解决基体效应、不平度效应和仪器一致性的方法和技术。燕山地区三个金矿区（点）的应用表明该方法可缩小找金矿的靶区，确定隐伏金矿体位置，划分金矿体的边界。     

吉林省兰家金矿床地质特征及控矿地质条件

古生代含硅质火山碎屑岩建造是兰家金矿床主要赋矿层位，并受印支－燕山期石英闪长岩和不同方向断裂控制，构成本区金矿成矿的重要地质前提。