Exceedingly Fast Copper(II)‐Promoted ortho CH Trifluoromethylation of Arenes using TMSCF3

The direct ortho‐trifluoromethylation of arenes, including heteroarenes, with TMSCF₃ has been accomplished by a copper(II)‐promoted C? H activation reaction which completes within 30 minutes. Mechanistic investigations are consistent with the involvement of C? H activation, rather than a simple electrophilic aromatic substitution (S_EAr), as the key step.     

Immuno‐Chemotherapeutic Platinum(IV) Prodrugs of Cisplatin as Multimodal Anticancer Agents

There is growing consensus that the clinical therapeutic efficacy of some chemotherapeutic agents depends on their off‐target immune‐modulating effects. Pt anticancer drugs have previously been identified to be potent immunomodulators of both the innate and the adaptive immune system. Nevertheless, there has been little development in the rational design of Pt‐based chemotherapeutic agents to exploit their immune‐activating capabilities. The FPR1/2 formyl peptide receptors are highly expressed in immune cells, as well as in many metastatic cancers. Herein, we report a rationally designed multimodal Pt^IV prodrug containing a FPR1/2‐targeting peptide that combines chemotherapy with immunotherapy to achieve therapeutic synergy and demonstrate the feasibility of this approach.     

Optoelectronic and Self‐assembly Properties of Porphyrin Derivatives with Click Chemistry Modification

A series of functionalized porphyrin molecules containing electron‐rich alkynes, synthesized by means of the Sonogashira coupling reaction were further modified by reacting the ethynyl groups with click reagent through a formal [2+2] click reaction. The photophysical and electrochemical properties of the porphyrin derivatives were studied by UV/Vis spectroscopy and cyclic voltammetry. We show that the optoelectronic properties are affected by the click reagent groups and central metal ions. The functionalized porphyrin molecules show strong charge‐transfer (CT) bands in the visible region (near‐IR region) and potent redox activities. Through a phase‐exchange self‐assembly method, the highly organized morphologies were observed by scanning electron microscopy (SEM). The functionalized porphyrin molecules represent an interesting set of candidates for optoelectronic device components. The effect of the metal ions or click reagent groups on the self‐assembly properties were also studied by the UV/Vis spectroscopic titration experiments.     

Boron‐Double‐Ring Sheet,Fullerene, and Nanotubes: Potential Hydrogen Storage Materials

Similar to carbon‐based graphene, fullerenes and carbon nanotubes, boron atoms can form sheets, fullerenes, and nanotubes. Here we investigate several of these novel boron structures all based on the boron double ring within the framework of density functional theory. The boron sheet is found to be metallic and flat in its ground state. The spherical boron cage containing 180 atoms is also stable and has I symmetry. Stable nanotubes are obtained by rolling up the boron sheet, and all are metallic. The hydrogen storage capacity of boron nanostructures is also explored, and it is found that Li‐decorated boron sheets and nanotubes are potential candidates for hydrogen storage. For Li‐decorated boron sheets, each Li atom can adsorb a maximum of 4 H₂ molecules with g_d=7.892 wt %. The hydrogen gravimetric density increases to g_d=12.309 wt % for the Li‐decorated (0,6) boron nanotube.     

High‐expression β1 adrenergic receptor/cell membrane chromatography method based on a target receptor to screen active ingredients from traditional Chinese medicines

β‐Adrenergic receptors are important targets for drug discovery. We have developed a new β₁‐adrenergic receptor cell membrane chromatography (β₁AR‐CMC) with offline ultra‐performance LC (UPLC) and MS method for screening active ingredients from traditional Chinese medicines. In this study, Chinese hamster ovary‐S cells with high β₁AR expression levels were established and used to prepare a cell membrane stationary phase in a β₁AR‐CMC model. The retention fractions were separated and identified by the UPLC–MS system. The screening results found that isoimperatorin from Rhizoma et Radix Notopterygii was the targeted component that could act on β₁AR in similar manner of metoprolol as a control drug. In addition, the biological effects of active component were also investigated in order to search for a new type of β₁AR antagonist. It will be a useful method for drug discovery as a leading compound resource.     

高分辨连续光源火焰原子吸收光谱法测定秀珍菇中金属元素

将秀珍菇样品用超纯水清洗后烘干至恒重,粉碎过0.149mm筛。称取适量样品(约0.5g),加入硝酸5mL及过氧化氢1mL进行微波消解。将溶液蒸至近干,残渣用硝酸(0.5+99.5)溶液溶解,并定容至25mL。取上述4种元素的标准溶液制备标准曲线,采用高分辨连续光源和低噪声线阵电荷耦合式检测器,按选定的仪器工作条件进行钙、铁、镁、锌4种元素的火焰原子吸收光谱顺序测定。按所提出的方法用于实际样品分析,加标回收率在95.5%~104%之间,测定值的相对标准偏差(n=6)均小于3%。     

靶向抑制DNA拓扑异构酶的抗肿瘤药物研究

DNA拓扑异构酶是真核细胞和原核细胞中的一种基本酶,广泛存在于细胞核中,对DNA的转录、复制以及基因表达过程中的DNA拓扑结构的改变起着重要的作用。研究发现DNA拓扑异构酶在肿瘤组织中高度表达,许多抗肿瘤药物的作用机制与抑制拓扑异构酶有关,目前拓扑异构酶已成为筛选抗肿瘤药物的重要靶点。     

金属标记结合高效液相色谱-选择离子监测质谱的蛋白质绝对定量新方法

建立了金属标记结合高效液相色谱-选择性离子监测质谱(SIM)的蛋白质绝对定量新方法。实验考察了金属标记效率、金属标记的稳定性、标记后肽段的色谱保留和质谱行为、新定量方法的线性范围和准确度。实验结果表明金属标记具有标记效率高,稳定性好,色谱保留行为一致等优点。另外,金属标记-选择离子监测质谱绝对定量方法灵敏度高,其定量限低至1 fmol,线性范围为1~500 fmol,线性范围内R2值大于0.99,具有良好的线性关系;经过测量,标准肽段的回收率为117.01%,说明该方法具有较高的准确度。将该方法应用于腾冲嗜热菌中烯醇酶蛋白的定量分析,相对标准偏差为5.47%,表明该方法的精密度高。以上结果表明该方法可以用于生物样本中的蛋白质的绝对定量分析,为比较简单的生物样本中蛋白质的绝对定量方法提供了一种新的选择。     

低温溶剂热法制备5V级性能优异的LiCr_(0.2)Ni_(0.4)Mn_(1.4)O_4正极材料(英文)

通过低温溶剂热的方法成功制备出了LiCr0.2Ni0.4Mn1.4O4尖晶石正极材料。通过此法,溶液的饱和蒸汽压急剧降低且在室温(25℃)下即可沸腾。所有的金属离子可在随后的热聚合过程中均匀分散且煅烧后所得材料无杂质相生成。采用了热重分析,X射线衍射,扫描电镜、循环伏安,交流阻抗等测试手段对材料进行了表征。结果表明:此法所得材料含有Mn3+,为Fd3m晶型,且其形貌规则、粒度分布均一。1C和10C下放电容量为140.5和121.0 mAh·g-1,10C下100次循环容量保持率高达96.9%。其优异的电化学性能可归因于均相的前驱体制备过程,高结晶度且无杂相生成,以及较高的锂离子扩散系数诸因素的共同作用。     

氮掺杂长竹节状碳纳米管的制备及其生长机理

采用电弧放电法,通过阳极棒与不锈钢片的共蒸发,制备了氮掺杂长竹节状碳纳米管(NDLBLCNTs)。借助扫描电子显微镜(SEM)、场发射高分辨透射电子显微镜(HRTEM)及其附带能量色散X射线(EDX)光谱仪和电子能量损失谱(EELS)、透射电子显微镜(TEM)等表征方法,对产物的形貌、结构和组成进行表征。表征结果表明,NDLBLCNTs的长度在640~835 nm之间,其内径在23~35 nm之间,外径在28~47 nm之间;且在每一节"竹节"与另一节"竹节"的连接处形成的内腔中均有一个黑色纳米颗粒,其直径尺寸以及产物中的NDLBLCNTs的含量均与熔化、蒸发的不锈钢片的面积有关。对NDLBLCNTs的生长机理进行了简单的探讨。