Building 2D classification models and 3D CoMSIA models on small-molecule inhibitors of both wild-type and T790M/L858R double-mutant EGFR

Molecular Diversity - Epidermal growth factor receptor (EGFR) has received widespread attention because it is an important target for anticancer drug design. Mutations in the EGFR, especially the...     

Facile radiosynthesis of <Superscript>18</Superscript>F-labeled β-glutamic acid as a new PET tracer for imaging lung cancer

In this paper, N-(2-[¹⁸F]fluoropropionyl)-β-glutamic acid 8 ([¹⁸F]FP-β-Glu), a new N-substituted ¹⁸F-labeled amino acid tracer, was synthesized from the precursor 4 (diethyl 3-(2-bromopropanamido)pentanedioate) via a two-step reaction on the modified FDG synthesizer. The radiochemical yield was 20 ± 5% (n = 10, decay-corrected) from [¹⁸F]fluoride within 40 min, the radiochemical purity was 98%. Moreover, microPET studies showed that [¹⁸F]FP-β-Glu 8 exhibited rapid tumor uptake and good tumor-to-lung ratio in SPC-A-1 tumor-bearing mice. A high accumulation of radioactivity was found in the kidneys and bladder, which suggested that the tracer was mainly eliminated through the urinary system.     

In‐situ preparation of porous monolithic polymer inside hollow fiber as a micro‐solid phase extraction device for glucocorticoids in cosmetics

Glucocorticoids have a certain whitening effect on the skin. However, frequent and long‐term use of cosmetics including glucocorticoids is harmful to health. Herein, we proposed a novel micro‐solid phase extraction method for the detection of prednisolone acetate, prednisone, and prednisolone in cosmetics coupled with high‐performance liquid chromatography. In this method, porous monolithic polymer micro‐extraction bars were prepared by “one‐step, one‐pot” in situ photopolymerization combined with sacrificial support in hollow fiber under water atmosphere. The crucial factors such as pH of sample solution, extraction, and elution times that influence micro‐extraction were optimized and found to be 9.0, 2 h, and 32 min, respectively. Under the optimum experimental conditions, the linear range of the calibration curves were from 5.0 to 2000 µg/L with correlation coefficients (R²) between 0.9922 and 0.9996. The limit of detection and limit of quantification were 1.5 µg/L and 5.0 µg/L, respectively, and the recoveries were found to be in range of 69.0–113.3%. The analysis of precision for intraday and interday were less than 10.40 and 10.59%. The device has been successfully achieved photopolymerization under water atmosphere. The results indicated that this method is simple, accurate, and satisfactory for the pretreatment and determination of glucocorticoids in complex cosmetics samples.     

Synthesis and evaluation of nitrate derivatives of colchicine as anticancer agents

To search for more potent antitumor agent,a series of novel nitric oxide-donating colchicine(Col) derivatives(6a-f,8a and b) were synthesized by coupling nitrates with N-methyl colchiceinamide.Their cytotoxicity against four human cancer cell lines in vitro were evaluated by MTT assay.It was found that many of the derivatives displayed significant activity,particularly,compounds 6c,8a and 8b showed more potent cytotoxic activities than Col.     

Chemical composition of PM_(2.5) during winter in Tianjin,China

PM2.5 samples for 24 h were collected during winter in Tianjin,China. The ambient mass concentration and chemical composition of the PM2.5 were determined. Ionic species were analyzed by ion chromatog-raphy,while carbonaceous species were determined with the IMPROVE thermal optical reectance(TOR) method,and inorganic elements were measured by inductively coupled plasma-atomic emission spec-trometer. The daily PM2.5 mass concentrations ranged from 48.2 to 319.2 g/m3 with an arithmetic average of 144.6 g/m3. ...     

Copper oxide nanoarray based on the substrate of Cu applied for the chemical sensor of hydrazine detection

This communication reports on a novel amperometric hydrazine sensor of CuO nanoarray based on a Cu substrate. Copper oxide nanoarray was directly grown on Cu substrates using a one-step facile hydrothermal method and was characterized using scanning electron microscopy and X-ray powder diffraction. The electrochemical study has shown that the CuO nanoarray exhibits higher catalytic effect on the hydrazine than the normal CuO nanoparticles. This may be attributed to the special structure of the nanomaterials esp. the substrate of the electric Cu. And the amperometric response showed that the CuO nanoarray modified glassy carbon electrode has a low detection and a high sensitivity for hydrazine.     

A new biflavonoid from Selaginella labordei Hieron.ex Christ

A new biflavonoid,2,3-dihydro-5,5″,7,7″,4′-pentahydroxy-6,6″-dimethyl-[3′-O-4′″]-biflavone 1 and two known biflavonoids 2,3″-dihydroochnaflavone 2 and 2″,3″-dihydro-3′,3′″-biapigenin 3 were isolated from the herb of Selaginella labordei Hieron.ex Christ.Their structures were elucidated by spectroscopic methods.     

钯作基体改进剂FIA－HG－GFAAS法测定锗及其机理研究

采用钯，钯－镁作基体改进剂，ＦＩＡ－ＨＧ－ＧＦＡＡＳ法成功地测定了锗。灵敏度、精密度和分析速度都得到很大的提高。峰值吸收的特征质量８．０ｐｇ，检出限１０．９ｐｇ，相对标准偏差０．３４％，同时探讨了基体改进剂钯的稳定作用机理及锗在石墨管中的原子化机理。