Two-Dimensional Detergent Expansion Strategy for Membrane Protein Studies

Detergents are the most frequently applied reagents in membrane protein (MP) studies. The limited diversity of one-head-one-tailed traditional detergents, however, is far from sufficient for structurally distinct MPs. Expansion of detergent repertoire has a continuous momentum. In line with the speculation that detergent pre-assembly exerts superiority, herein we report for the first time cross-conjugation of two series of monomeric detergents for constructing a two-dimensional library of dimeric detergents. Optimum detergents stood out with unique preferences in the systematic evaluation of individual MPs. Furthermore, unprecedented hybrid detergents 14M8G and 14M9G enabled high-quality EM study of transporter MsbA and NMR study of G protein-coupled receptor A_2AAR, respectively. Given the abundance of cross-coupling chemistries, comprehensive diversity could be readily covered that would facilitate the finding of new detergents for the manipulation of thorny MPs and innovation of the functional and structural study in future.     

Hydrophilic Cu3BiS3 Nanoparticles for Computed Tomography Imaging and Photothermal Therapy

Hydrophilic Cu₃BiS₃ nanoparticles (NPs) have been prepared using the thermal decomposition of precursor complexes in oily‐mixed solvent followed by coating the produced Cu₃BiS₃ NPs with polyvinylpyrrolidone (PVP). The resulting Cu₃BiS₃/PVP NPs remain stable in aqueous solutions over a long period of time, and meanwhile, they show low in vitro cytotoxicity and negligible toxicity to mice in vivo. Cu₃BiS₃/PVP NPs could operate as an efficient dual‐modal contrast agent to simultaneously enhance X‐ray computed tomography imaging and photothermal imaging of tumor model in vivo. Moreover, highly efficient ablation of cancer cells both in vitro and in vivo has been successfully achieved by combining Cu₃BiS₃/PVP NPs with near‐infrared (NIR) laser irradiation. All of the positive results in this study highlight that Cu₃BiS₃/PVP NPs could serve as a promising platform for cancer diagnosis and therapy.     

Using aptamers to visualize and capture cancer cells

Since diseased cells exist in exceedingly low concentration at the early stage of cancer, highly sensitive imaging and detection methods are required. By improving the methods for capturing and visualizing cancer cells, clinicians can diagnose metastatic relapse, stratify patients for therapeutic purposes, monitor response to drugs and therapies, and track tumor progression. Therefore, using advanced biotechnological and analytical methods combined with cell-SELEX (systematic evolution of ligands by exponential enrichment)-based aptamers, we improved the capture and visualization of diseased cells in a manner that is inexpensive, simple, sensitive, and fast. This multiplexed cancer detection platform therefore improves our control over a range of clinical exigencies, including cancer diagnosis, therapeutic modalities, and drug delivery systems.     

铈(Ⅲ)-氨基酸-咪唑三元配合物的表征和循环伏安行为研究

合成了铈（Ⅲ）－色氨酸－咪唑和铈（Ⅲ）－苯丙氨酸－咪唑三元配合物,对配合物进行了元素分析、摩尔电导测试、热重－差热分析及红外光谱分析,确定了配合物的组成和成键特征,并用循环伏安法研究了铈（Ⅲ）离子、铈（Ⅲ）与氨基酸及咪唑混合溶液、铈（Ⅲ）二元及三元配合物在玻碳电极上的电化学行为。实验结果表明,在－０．１０～１．１０Ｖ（ｖｓ．ＳＣＥ）电位扫描范围内,两种铈（Ⅲ）三元配合物显示了安全不可逆的电子迁移过     

红螺菌吸附重金属红外光谱及原子力成像比较研究

研究了红螺菌对Cu2 、Cr6 的吸附行为.结果表明,在pH 2.9,35℃微光厌氧条件下,菌体对40mg/L Cu2 、Cr6 最大吸附率分别为94%、83.2%.利用红外光谱、原子力成像等方法,对吸附Cu2 、Cr6 前后的红螺茵进行了研究.红外光谱表明,羟基峰位红移,吸附Cu2 后峰位移动为22cm-1,吸附Cr6 后移动28cm-1,其它峰没有漂移,并且峰形基本保持不变,说明吸附后菌体的主要成分及结构保持完整.原子力成像表明,吸附前胞外聚合物分散分布,吸附后胞外聚合物出现交联,形成一个新的二维网状结构,并且吸附Cu2 后的交联程度比吸附Cr6 高.     

气相色谱-质谱联用法测定动物组织中氯霉素、氟甲砜霉素和甲砜霉素的残留量

建立了气相色谱-负离子化学电离源质谱同时测定动物组织中氯霉素(CAP)、甲砜霉素(TAP)和氟甲砜霉素(FF)残留量的方法。样品用乙酸乙酯提取,正己烷分配去脂肪,再用Florisil柱进一步净化,甲苯作为反应介质,用N,O-双(三甲基硅基)三氟乙酰胺(BSTFA)-三甲基氯硅烷(TMCS)(体积比为99∶1)进行硅烷化处理,用间硝基氯霉素(m-CAP)作为内标进行测定。CAP的检测限可达到0.03 μg/kg,TAP和FF的检测限可达到0.2 μg/kg;上述3种药物的标准曲线的线性相关系数均大于0.99。CAP,FF和TAP的批内测定的精密度(以相对标准偏差表示)依次为5.5%,10.4%和8.8%;批间测定的精密度依次为7.4%,20.7%和19.1%。回收率为80.0%~111.5%,相对标准偏差为1.2%~15.4%。该方法前处理步骤简单,处理后杂质干扰少,灵敏度高,适用性强,可用于猪肉及禽类、水产品等多种动物组织中氯霉素类药物残留的检测。     

高效液相色谱法同时测定大豆中12种酰胺类除草剂的残留量

建立了大豆中12种酰胺类除草剂多残留量同时检测的高效液相色谱方法。样品经丙酮提取、弗罗里硅土柱净化后,用高效液相色谱-二极管阵列检测器检测。在0.05～1.0 mg/kg的添加水平范围内,12种酰胺类药物的回收率为75%～102%,相对标准偏差为1.9%～16.1%；12种酰胺类除草剂的测定低限均能达到国家相关的残留限量要求。对样品的前处理条件进行了研究和优化,经商品化的固相萃取柱净化过的样品干扰杂质较少,有利于后续的检测分析和方法的推广应用。该方法能够在35 min内完成一次分析,具有快速、灵敏、准确、可靠的特点。     

新疆吐鲁番盆地的嗜热细菌

从新疆吐鲁番盆地分离出十二株嗜热(生长温度为:25℃～73℃,最适温度为:45℃～60℃)、革兰氏阳性芽孢杆菌,经鉴定为Bacillus spp。     

环氧树脂/累托土纳米复合材料结构转变特性的正电子谱学研究

采用正电子湮没寿命谱(PALS)技术,通过探测聚酰胺固化环氧树脂(epoxy)及环氧树脂/累托土(epoxy/rectorite)纳米复合材料分别在30～473 K及30～493 K温度区间内自由体积特性的变化,得到了epoxy和epoxy/rectorite两种材料中3个结构转变点温度为:次级转变点温度Tγ分别为160,120 K;玻璃化转变点温度Tg分别为270,260 K和橡胶态到粘流态的转变点温度Tf＝380 K(两种材料相同).比较两种材料的结构转变点,发现纳米复合材料Tf,Tg和Tγ分别比环氧树脂低0,10 K和40 K.说明累托土的加入影响了复合材料低温下的自由体积特性.在温度高于熔融温度Tm时,发现两种样品中自由体积浓度有较快的下降,归因为材料中分子链段运动非常剧烈,较小的孔洞消失.     

变截面黏弹性直杆纵振时复频率分析的差分解法

从一维黏弹性本构方程出发,导出了黏弹性变截面直杆纵向振动微分方程的一般形式,采用了有限差分法,并以二阶矩阵表示的递推形式,建立了该问题的复特征值方程组。两种Maxwell黏弹性变截面（指数指数、线性函数）直杆的数值计算表明,该方法运算简单,计算精度高,能适用于求解任意变截面黏弹性直属的纵向自由振动问题。