FOS-μSIA-LOV荧光猝灭法测定头孢拉定胶囊的含量

建立FOS-μSIA-LOV光谱在线过程分析,实现自动化含量测定头孢拉定(RAD)。通过程序编写,元件智能控制,优化实验条件,考察了RAD中的辅料,载液,进样体积等因素。优选条件为:载液吸入体积为500μL;RAD吸入体积为100μL;打出体积的流速为150μL·s~(-1),RAD质量浓度c与ΔF的线性关系为ΔF=812.6c+284(0.05~0.5mg·mL~(-1),r=0.999 5),RSD为4.4%,回收率为101%~103%。通过FOS-μSIA-LOV系统和设定特定检测程序,实现自动化在线过程分析,具有重现性好、节约试剂、省时省力的优点。     

用三维电镜图像数据测试空穴形状

用碳化硅强化金属基复合材料制作的不同切口的拉伸试样进行了拉伸试验并使用三维电子扫描显微镜对拉伸延性断面进行了微小空穴的三维形状测试，分析了在不同应力三维度下空穴聚合时空穴几何形状的变化，为准确模拟金属基复合材料在多向外载荷下的损伤过程，判断延性损伤机理提供了科学依据。     

Catalytic Asymmetric Dearomatization by Visible‐Light‐Activated [2+2] Photocycloaddition

A novel method for the catalytic asymmetric dearomatization by visible‐light‐activated [2+2] photocycloaddition with benzofurans and one example of a benzothiophene is reported, thereby providing chiral tricyclic structures with up to four stereocenters including quaternary stereocenters. The benzofurans and the benzothiophene are functionalized at the 2‐position with a chelating N‐acylpyrazole moiety which permits the coordination of a visible‐light‐activatable chiral‐at‐rhodium Lewis acid catalyst. Computational molecular modeling revealed the origin of the unusual regioselectivity and identified the heteroatom in the heterocycle to be key for the regiocontrol.     

Self-directed chain reaction by small ketones with the dangling bond site on the Si(100)-(2 x 1)-H surface: acetophenone, a unique example

Using scanning tunneling microscope (STM) at 300 K, we studied the growth of one-dimensional molecular assemblies (molecular lines) on the Si(100)-(2 x 1)-H surface through the chain reaction of small ketone (CH 3COCH 3, PhCOPh, and PhCOCH 3) molecules with dangling bond (DB) sites of the substrate. Acetone and benzophenone show the growth of molecular lines exclusively parallel to the dimer row direction. In contrast, acetophenone molecules show some molecular lines perpendicular, in addition to parallel, to the dimer row direction. Most of the molecular lines perpendicular to the dimer row direction were grown by self-turning the propagation direction of a chain reaction from parallel to perpendicular directions relative to the dimer row. A chiral center created upon adsorption of an acetophenone molecule allows the adsorbed molecules to align with identical as well as alternate enantiomeric forms along the dimer row direction, whereas such variations in molecular arrangement are not observed in the case of acetone and benzophenone molecules. The observed molecular lines growth both parallel and perpendicular to dimer row directions appears to be unique to acetophenone among all the molecules studied to date. Hence, the present study opens new possibility for fabricating one-dimensional molecular assemblies of various compositions in both high-symmetry directions on the Si(100)-(2 x 1)-H surface.     

Real-time detection of<Emphasis Type="SmallCaps"> L</Emphasis>-glutamate released from C6 glioma cells using a modified enzyme-luminescence method

There is an increasing interest in new strategies to detect neurotransmitters released from nerve cells in real time for brain science, drug assessment, and so on. Previously we reported real-time monitoring of dopamine release from nerve model cells by enzyme-catalyzed luminescence measurement with tyramine oxidase and peroxidase. In the present study, the system was modified with glutamate oxidase instead of tyramine oxidase to detect L-glutamate sensitively (≈ 10 nM) and rapidly with high temporal resolution (<1 s). We applied this modified method successfully to perform real-time monitoring of L-glutamate release from brain model cell (C6 glioma cell) using a luminescence plate reader upon stimulation with high concentration of KCl (>10 mM) or 5-hydroxytryptamine (>1 μM). The measurement solution was not toxic and therefore the L-glutamate release from the cell was measured by the second stimulation after exchanging the measurement solution. We conclude that the developed monitoring system is suitable for real-time detection of dynamic L-glutamate release from nerve cells in vitro and will be suitable for application in assessment of drugs acting on the nervous system. Figure Enzyme luminescence detection of L-glutamate released from cells     

Photo-responsive NIR-II biomimetic nanomedicine for efficient cancer-targeted theranostics

In pancreatic cancer, the special barrier system formed by a large number of stromal cells severely hinders drug penetration in deep tumor tissues, resulting in low treatment efficiency. Cell membrane protein-camouflaged liposomal nanomedicines have cancer cell targeting abilities, whereas near-infrared two-zone (NIR-II) fluorescence imaging can achieve deep tissue penetration due to its long light wavelength (1,000–1,700 nm). To combine the cell membrane-based biomimetic technology with NIR-II fluorescence imaging, we constructed a biomimetic nanomedicine (BLIPO-I/D) by camouflaging indocyanine green-doxorubicin (ICG-DOX) liposomes with SW1990 pancreatic cancer cell membrane. The nanomedicine exhibited light-controlled DOX release and high pancreatic cancer treatment efficiency in vitro and in vivo. BLIPO-I/D showed the ability of targeted delivery of a large number of liposomes to pancreatic tumor tissues through homologous targeting of SW1990 cell membranes, which increased the NIR-II fluorescence imaging intensity. Irradiation of the liposomes taken up by pancreatic tumor tissues with near-infrared light (808 nm) triggered the rapid release of DOX from the liposomes, induced the photothermal and photodynamic effects of ICG, which exerted anti-tumor effects. Therefore, the fabricated biomimetic liposomal nanomedicine BLIPO-I/D is expected to achieve precise theranostics of pancreatic cancer.