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181.
李瀛  达世俊 《合成化学》1997,5(2):168-170
以2-萘甲酸为原料,经硝化,酯化,重氮化,选择性催化氢化,BOC酸酐保护等六步反应,完成了N-BOC-8氨甲基-2-萘甲酸(1a)的合成,为化合物1的合成提供了新的合成途径。  相似文献   
182.
Panax quinquefolius, a popular medicinal herb, has been cultivated in China for many years. In this work, the region-specific profiles of metabolites in P. quinquefolius from Wendeng was investigated using liquid-chromatography–quadrupole–time-of-flight-(LC–Q–TOF)-based metabolomics analysis. The three most abundant biomarkers, identified as ginsenoside Rb3, notoginsenoside R1, and ginsenoside Rc, were the representative chemical components employed in the network pharmacology analysis. In addition, molecular docking and western blotting analyses revealed that the three compounds were effective binding ligands with Hsp90α, resulting in the inactivation of SRC and PI3K kinase, which eventually led to the inactivation of the Akt and ERK pathways and lung cancer suppression. The outcomes obtained herein demonstrated the intriguing chemical characteristics and potential functional activities of P. quinquefolius from Wendeng.  相似文献   
183.
Effective intracerebral delivery is key for glioma treatment. However, the drug delivery system within the brain is largely limited by its own adverse physical and chemical properties, low targeting efficiency, the blood–brain barrier and the blood–brain tumor barrier. Herein, we developed a simple, safe and efficient biomimetic nanosuspension. The C6 cell membrane (CCM) was utilized to camouflaged the 10-hydroxycamptothecin nanosuspension (HCPT-NS) in order to obtain HCPT-NS/CCM. Through the use of immune escape and homotypic binding of the cancer cell membrane, HCPT-NS/CCM was able to penetrate the blood–brain barrier and target tumors. The HCPT-NS is only comprised of drugs, as well as a small amount of stabilizers that are characterized by a simple preparation method and high drug loading. Similarly, the HCPT-NS/CCM is able to achieve targeted treatment of glioma without any ligand modification, which leads it to be stable and efficient. Cellular uptake and in vivo imaging experiments demonstrated that HCPT-NS/CCM is able to effectively cross the blood–brain barrier and was concentrated at the glioma site due to the natural homing pathway. Our results reveal that the glioma cancer cell membrane is able to promote drug transport into the brain and enter the tumor via a homologous targeting mechanism.  相似文献   
184.
Taking the advantage of reduced scattering and low autofluorescence background, the NIR fluorescence probes, such as fluorescence proteins, organic molecules and nanoparticles, not only hold the promise of in vivo imaging of biological processes in physiology and pathology with high signal-to-noise ratio, but also for clinical diagnosis. In this review, we provide an overview of the recent progress on NIR probes, focusing on fundamental mechanisms of NIR dyes and nanoparticles, and protein engineering strategies for NIR proteins.  相似文献   
185.
186.
Halogen bonding (XB) has emerged as an important bonding motif in supramolecules and biological systems. Although regarded as a strong noncovalent interaction, benchmark measurements of the halogen bond energy are scarce. Here, a combined anion photoelectron spectroscopy and density functional theory (DFT) study of XB in solvated Br? anions is reported. The XB strength between the positively‐charged σ‐hole on the Br atom of the bromotrichloromethane (CCl3Br) molecule and the Br? anion was found to be 0.63 eV (14.5 kcal mol?1). In the neutral complexes, Br(CCl3Br)1,2, the attraction between the free Br atom and the negatively charged equatorial belt on the Br atom of CCl3Br, which is a second type of halogen bonding, was estimated to have interaction strengths of 0.15 eV (3.5 kcal mol?1) and 0.12 eV (2.8 kcal mol?1).  相似文献   
187.
While carbon dots (C‐dots) have been extensively investigated pertaining to their fluorescent, phosphorescent, electrochemiluminescent, optoelectronic, and catalytic features, their inherent chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) properties are unknown. By virtue of their hydrophilicity and abundant exchangeable protons of hydroxyl, amine, and amide anchored on the surface, we report here that C‐dots can be adapted as effective diamagnetic CEST (diaCEST) MRI contrast agents. As a proof‐of‐concept demonstration, human glioma cells were labeled with liposomes with or without encapsulated C‐dots and implanted in mouse brain. In vivo CEST MRI was able to clearly differentiate labeled cells from non‐labeled cells. The present findings may encourage new applications of C‐dots for in vivo imaging in deep tissues, which is currently not possible using conventional fluorescent (near‐infrared) C‐dots.  相似文献   
188.
FTIR-ATR has been used for understanding the interaction between bacteria and surfaces in the adsorption progress.  相似文献   
189.
用激光测微法跟踪了双(对甲苯磺酸)-2,4-己二炔-1,6-二醇酯(TS)固态晶相热聚合时宏观尺寸的变化,由此推算TS聚合时晶胞参数的变化。结果表明,在形成聚合物PTS大分子链的c轴方向上一直收缩,而在横向a、b方向上则是先膨胀后收缩。  相似文献   
190.
紫外-可见光谱-偏最小二乘法测定渣油四组分含量   总被引:4,自引:0,他引:4  
褚小立  袁洪福  陆婉珍 《分析化学》2000,28(12):1457-1461
用已建立的渣油聚类和识别模型将渣油分为坟渣油、减压渣油和加氢渣油,用紫外-可见光谱-偏最小二乘法(UV-PLS)分别建立了这3种渣油的饱和烃、芳烃、胶质和沥青质四组分测定模型。该方法的测定结果与经典洗脱色谱法(EC)的结果相吻合。与EC方法相比,该方法具有快速、操作简单、不需分离,重复性好等特点。  相似文献   
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