Graphene Saturable Absorber Mirror for Mode-Locked Orange Pulse Laser

Journal of Russian Laser Research - We demonstrate a passively-mode-locked Pr3+: LuLiF4 laser operated at the 604 nm orange wave-length, using monolayer graphene as a saturable absorber. The...     

Simultaneous Removal of Antibiotics and Heavy Metals with Poly(Aspartic Acid)-Based Fenton Micromotors

The discharge of diverse pollutants has led to a complex water environment and posed a huge health threat to humans and animals. Self-propelled micromotors have recently attracted considerable attention for efficient water remediation due to their strong localized mass transfer effect. However, a single functionalized component is difficult to tackle with multiple contaminants and requires to combine different decontamination effects together. Here, we introduced a multifunctional micromotor to implement the adsorption and degradation roles simultaneously by integrating the poly(aspartic acid) (PASP) adsorbent with a MnO₂-based catalyst. The as-prepared micromotors are well propelled in contaminated waters by MnO₂ catalyzing hydrogen peroxide. In addition, the catalytic ramsdellite MnO₂(R-MnO₂) inner layer is decorated with Fe₂O₃ nanoparticles to improve their catalytic performance, contributing to an excellent degradation ability with 90% tetracycline (TC) removal in 50 minutes by enhanced Fenton-like reactions. Combining the attractive adsorption capability of poly (aspartic acid) (PASP), the composite micromotors offer an efficient removal of heavy metal ions in short time. Moreover, the designed micromotors are able to simultaneously remove antibiotic and heavy metals in mixed contaminants circumstance just in single treatment. This multifunctional micromotor with distinctive decontamination ability exhibits a promising prospective in treating multiple pollutants in the future.     

FCC硫转移剂MgAlCuFe复合氧化物的结构与性能:金属盐前体的影响

分别以硝酸盐、盐酸盐和硫酸盐为金属盐前体,采用共沉淀法合成了MgAlCuFe类水滑石前驱体,经过700℃焙烧6h后,制得三种新型FCC硫转移剂.运用X射线衍射、热重、氮气吸附和红外光谱对这三种硫转移剂的结构和性能进行了表征,并采用改装的WRP-3热重天平评价了其氧化吸硫和还原脱硫的性能.结果表明,三种金属盐均可得到结构规整的类水滑石前驱体,经过焙烧后得到复合氧化物MgAlCuFe.与采用盐酸盐和硫酸盐作前体相比,由硝酸盐制得的硫转移剂具有较大的比表面积,其饱和吸附硫容和氧化吸硫速率均较高,6min可达到1.54g/g的饱和吸附能力,同时具有较强的还原脱硫能力.     

Interaction between sodium tanshinone IIA sulfonate and the adriamycin semiquinone free radical: A possible mechanism for antagonizing adriamycin-induced cardiotoxity

Adriamycin (ADR) is a powerful and widely used antitumor drug, but its dose dependent cardiotoxicity limits its application. This side effect is believed to be caused by the adriamycin semiquinone free radical (ASFR). The primary focus of this work is to test effects of sodium tanshinone IIA sulfonate (STS) on ASFR and adriamycin–induced lipid peroxidation. It was found that ADR, whether in the system of heart homogenate, heart mitochondria or heart submitochondria, with NADH as the substrate or in xanthine/xanthine oxidase under anaerobic conditions, all produced ASFR rapidly. STS was shown to effectively scavenge ASFR in all these systems and postpone the appearance of ASFR. The delayed time was proportional to the amount of STS. Under aerobic conditions, ASFR could be oxidized to generate oxygen free radicals. STS could not scavenge these oxygen free radicals, but it could effectively scavenge lipid free radicals generated from membrane lipid peroxidation of heart mitochondria. STS could significantly reduce mitochondrial swelling and lipid peroxidation induced by ADR. Animal experiments show that treatment of STS could inhibit endogenous lipid peroxidation caused by ADR. Here, a protective mechanism of STS is suggested that STS can rapidly and univalently oxidize ASFR, causing the cycle of adriamycin between its quinone form and semiquinone form and inhibiting the accumulation of ASFR. Under aerobic condition, STS can protect heart mitochondria by scavenging lipid free radicals generated from adriamycin-induced mitochondrial lipid peroxidation. This investigation shows that STS may be a physiological drug to antagonize the cardiotoxicity of ADR.     

铁(III)卟啉催化β-胡萝卜素分解动力学研究

使用BeckmannDU-8B紫外可见分光光度计研究了以氯合四－间三甲苯基卟啉铁（Ⅲ）（FeTMPCl）为催化剂，间氯过氧化苯甲酸（mCPBA）为氧化剂，咪唑（I_m）、2－甲基咪唑（MeI_m）、2－乙基－4－甲基咪唑（EMI_m）为轴向配体，催化β-胡萝卜素（β－cte）氧化分解为维生素A的动力学规律，提出了反应机理，研究了温度、催化剂浓度、氧化剂浓度及轴向配体对反应速率的影响，应用Gauss－Newton－Marquardt方法求得各基元反应的有关动力学参数．     

气相色谱中测定死时间的Grobler－Balizs法和Ambrus法的比较

经理论推导和实验数据验证，证明测定死时间的Ｇｒｏｂｌｅｒ－Ｂａｌｉｚｓ法和Ａｍｂｒｕｓ法是同一的。     

SNAP-tag蛋白标签技术与荧光分析法在蛋白原位分析中的联合应用

为将生物体内微观的蛋白行为可视化并以宏观信号呈现出来对蛋白进行实时、动态分析，借助SNAP-tag蛋白标签技术与有机小分子荧光染料，构建了一系列用于活细胞内实时监测目标蛋白的免洗荧光探针。标签蛋白SNAP-tag能够特异性识别探针中的苄基鸟嘌呤，从而使目标蛋白共价连接上荧光团（萘酰亚胺），携带上荧光信使。此外，由于萘酰亚胺从水环境中被牵引至SNAP-tag蛋白的疏水空腔，其荧光信号呈现出2~13倍的增强。通过SNAP-tag标签蛋白与目标蛋白的融合，该荧光探针实现了对活细胞内线粒体蛋白CoX8A及核内蛋白H2B特异性识别，在免洗条件下完成了对目标蛋白的实时追踪及原位分析。     

Different catalysis role of in‐loop and out‐of‐loop waters in assisting HNS/HSN proton transfer isomerizations: Bridging vs. surrounding effect

In this work, a density function theory (DFT) study is presented for the HNS/HSN isomerization assisted by 1–4 water molecules on the singlet state potential energy surface (PES). Two modes are considered to model the catalytic effect of these water molecules: (i) water molecule(s) participate directly in forming a proton transfer loop with HNS/HSN species, and (ii) water molecules are out of loop (referred to as out‐of‐loop waters) to assist the proton transfer. In the first mode, for the monohydration mechanism, the heat of reaction is 21.55 kcal · mol^?1 at the B3LYP/6‐311++G** level. The corresponding forward/backward barrier lowerings are obtained as 24.41/24.32 kcal · mol^?1 compared with the no‐water‐assisting isomerization barrier T (65.52/43.87 kcal · mol^?1). But when adding one water molecule on the HNS, there is another special proton‐transfer isomerization pathway with a transition state 10T′ in which the water is out of the proton transfer loop. The corresponding forward/backward barriers are 65.89/65.89 kcal · mol^?1. Clearly, this process is more difficult to follow than the R–T–P process. For the two‐water‐assisting mechanism, the heat of reaction is 19.61 kcal · mol^?1, and the forward/backward barriers are 32.27/12.66 kcal · mol^?1, decreased by 33.25/31.21 kcal · mol^?1 compared with T. For trihydration and tetrahydration, the forward/backward barriers decrease as 32.00/12.60 (30T) and 37.38/17.26 (40T) kcal · mol^?1, and the heat of reaction decreases by 19.39 and 19.23 kcal · mol^?1, compared with T, respectively. But, when four water molecules are involved in the reactant loop, the corresponding energy aspects increase compared with those of the trihydration. The forward/backward barriers are increased by 5.38 and 4.66 kcal · mol^?1 than the trihydration situation. In the second mode, the outer‐sphere water effect from the other water molecules directly H‐bonded to the loop is considered. When one to three water molecules attach to the looped water in one‐water in‐loop‐assisting proton transfer isomerization, their effects on the three energies are small, and the deviations are not more than 3 kcal · mol^?1 compared with the original monohydration‐assisting case. When adding one or two water molecules on the dihydration‐assisting mechanism, and increasing one water molecule on the trihydration, the corresponding energies also are not obviously changed. The results indicate that the forward/backward barriers for the three in‐loop water‐assisting case are the lowest, and the surrounding water molecules (out‐of‐loop) yield only a small effect. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006     

Chromogenic reaction of bromopyrogallol red with tri- and hexavalent chromium in the presence of cetyltrimethyl ammonium bromide and its application in Cr speciation

The coordination reactions of bromopyrogallol red (BPR) with tri- and hexavalent chromium in the presence of cetyltrimethylammonium bromide (CTAB) have been studied by absorption spectrometry. Results show that the reactions of Cr(VI) and Cr(III) with BPR in the absence or presence of CTAB have different temperature dependences. The reaction mechanism of Cr(VI) is that Cr(VI) is first reduced by BPR to Cr(III) and then the Cr(III) produced reacts with BPR. Based on the study on the coordination reactions and the effects of surfactants upon them, a simple, rapid, sensitive and accurate method for Cr speciation has been developed. Over the range of 0–8 g Cr(VI) or 0–12g Cr(III) per 25ml final volume, the calibration curve is linear with a detection limit of 3.5 × 10^–7 mol/1 for Cr(VI) or 4.4 × 10^–7 mol/1 for Cr(III).     

刺激响应型聚合物前药

前药(prodrug)是一类经过生物体内转化后才具有药理作用的化合物。与传统纳米药物输送系统相比具有载药率确定、稳定性高、爆释现象小等优点。但是,前药本身也面临着可控性,特异性释药不足而引起效果不佳等问题。因此,能够靶向病灶部位并能够针对病灶部位进行特异性释药的刺激敏感型前药受到广泛研究。本文以国内外学者及本课题组的研究成果为基础,以肿瘤部位特殊的生理环境为背景,综述了近年来pH敏感、温敏、氧化还原敏感、酶敏感等生物刺激响应型抗肿瘤聚合物前药的研究进展。